Updated assimp to commit 1d565b0 with iFire

Signed-off-by: RevoluPowered <gordon@gordonite.tech>
Signed-off-by: K. S. Ernest (iFIre) Lee <ernest.lee@chibifire.com>

33 files changed, 16421 insertions, 0 deletions

diff --git a/thirdparty/assimp/code/FBX/FBXAnimation.cpp b/thirdparty/assimp/code/FBX/FBXAnimation.cpp
new file mode 100644
index 0000000000..874914431b
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXAnimation.cpp
@@ -0,0 +1,305 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXAnimation.cpp
+ *  @brief Assimp::FBX::AnimationCurve, Assimp::FBX::AnimationCurveNode,
+ *         Assimp::FBX::AnimationLayer, Assimp::FBX::AnimationStack
+ */
+
+#ifndef ASSIMP_BUILD_NO_FBX_IMPORTER
+
+#include "FBXParser.h"
+#include "FBXDocument.h"
+#include "FBXImporter.h"
+#include "FBXDocumentUtil.h"
+
+namespace Assimp {
+namespace FBX {
+
+using namespace Util;
+
+// ------------------------------------------------------------------------------------------------
+AnimationCurve::AnimationCurve(uint64_t id, const Element& element, const std::string& name, const Document& /*doc*/)
+: Object(id, element, name)
+{
+    const Scope& sc = GetRequiredScope(element);
+    const Element& KeyTime = GetRequiredElement(sc,"KeyTime");
+    const Element& KeyValueFloat = GetRequiredElement(sc,"KeyValueFloat");
+
+    ParseVectorDataArray(keys, KeyTime);
+    ParseVectorDataArray(values, KeyValueFloat);
+
+    if(keys.size() != values.size()) {
+        DOMError("the number of key times does not match the number of keyframe values",&KeyTime);
+    }
+
+    // check if the key times are well-ordered
+    if(!std::equal(keys.begin(), keys.end() - 1, keys.begin() + 1, std::less<KeyTimeList::value_type>())) {
+        DOMError("the keyframes are not in ascending order",&KeyTime);
+    }
+
+    const Element* KeyAttrDataFloat = sc["KeyAttrDataFloat"];
+    if(KeyAttrDataFloat) {
+        ParseVectorDataArray(attributes, *KeyAttrDataFloat);
+    }
+
+    const Element* KeyAttrFlags = sc["KeyAttrFlags"];
+    if(KeyAttrFlags) {
+        ParseVectorDataArray(flags, *KeyAttrFlags);
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+AnimationCurve::~AnimationCurve()
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+AnimationCurveNode::AnimationCurveNode(uint64_t id, const Element& element, const std::string& name, 
+        const Document& doc, const char* const * target_prop_whitelist /*= NULL*/, 
+        size_t whitelist_size /*= 0*/)
+: Object(id, element, name)
+, target()
+, doc(doc)
+{
+    const Scope& sc = GetRequiredScope(element);
+
+    // find target node
+    const char* whitelist[] = {"Model","NodeAttribute","Deformer"};
+    const std::vector<const Connection*>& conns = doc.GetConnectionsBySourceSequenced(ID(),whitelist,3);
+
+    for(const Connection* con : conns) {
+
+        // link should go for a property
+        if (!con->PropertyName().length()) {
+            continue;
+        }
+
+        if(target_prop_whitelist) {
+            const char* const s = con->PropertyName().c_str();
+            bool ok = false;
+            for (size_t i = 0; i < whitelist_size; ++i) {
+                if (!strcmp(s, target_prop_whitelist[i])) {
+                    ok = true;
+                    break;
+                }
+            }
+
+            if (!ok) {
+                throw std::range_error("AnimationCurveNode target property is not in whitelist");
+            }
+        }
+
+        const Object* const ob = con->DestinationObject();
+        if(!ob) {
+            DOMWarning("failed to read destination object for AnimationCurveNode->Model link, ignoring",&element);
+            continue;
+        }
+
+        // XXX support constraints as DOM class
+        //ai_assert(dynamic_cast<const Model*>(ob) || dynamic_cast<const NodeAttribute*>(ob));
+        target = ob;
+        if(!target) {
+            continue;
+        }
+
+        prop = con->PropertyName();
+        break;
+    }
+
+    if(!target) {
+        DOMWarning("failed to resolve target Model/NodeAttribute/Constraint for AnimationCurveNode",&element);
+    }
+
+    props = GetPropertyTable(doc,"AnimationCurveNode.FbxAnimCurveNode",element,sc,false);
+}
+
+// ------------------------------------------------------------------------------------------------
+AnimationCurveNode::~AnimationCurveNode()
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+const AnimationCurveMap& AnimationCurveNode::Curves() const
+{
+    if ( curves.empty() ) {
+        // resolve attached animation curves
+        const std::vector<const Connection*>& conns = doc.GetConnectionsByDestinationSequenced(ID(),"AnimationCurve");
+
+        for(const Connection* con : conns) {
+
+            // link should go for a property
+            if (!con->PropertyName().length()) {
+                continue;
+            }
+
+            const Object* const ob = con->SourceObject();
+            if(!ob) {
+                DOMWarning("failed to read source object for AnimationCurve->AnimationCurveNode link, ignoring",&element);
+                continue;
+            }
+
+            const AnimationCurve* const anim = dynamic_cast<const AnimationCurve*>(ob);
+            if(!anim) {
+                DOMWarning("source object for ->AnimationCurveNode link is not an AnimationCurve",&element);
+                continue;
+            }
+
+            curves[con->PropertyName()] = anim;
+        }
+    }
+
+    return curves;
+}
+
+// ------------------------------------------------------------------------------------------------
+AnimationLayer::AnimationLayer(uint64_t id, const Element& element, const std::string& name, const Document& doc)
+: Object(id, element, name)
+, doc(doc)
+{
+    const Scope& sc = GetRequiredScope(element);
+
+    // note: the props table here bears little importance and is usually absent
+    props = GetPropertyTable(doc,"AnimationLayer.FbxAnimLayer",element,sc, true);
+}
+
+// ------------------------------------------------------------------------------------------------
+AnimationLayer::~AnimationLayer()
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+AnimationCurveNodeList AnimationLayer::Nodes(const char* const * target_prop_whitelist /*= NULL*/,
+    size_t whitelist_size /*= 0*/) const
+{
+    AnimationCurveNodeList nodes;
+
+    // resolve attached animation nodes
+    const std::vector<const Connection*>& conns = doc.GetConnectionsByDestinationSequenced(ID(),"AnimationCurveNode");
+    nodes.reserve(conns.size());
+
+    for(const Connection* con : conns) {
+
+        // link should not go to a property
+        if (con->PropertyName().length()) {
+            continue;
+        }
+
+        const Object* const ob = con->SourceObject();
+        if(!ob) {
+            DOMWarning("failed to read source object for AnimationCurveNode->AnimationLayer link, ignoring",&element);
+            continue;
+        }
+
+        const AnimationCurveNode* const anim = dynamic_cast<const AnimationCurveNode*>(ob);
+        if(!anim) {
+            DOMWarning("source object for ->AnimationLayer link is not an AnimationCurveNode",&element);
+            continue;
+        }
+
+        if(target_prop_whitelist) {
+            const char* s = anim->TargetProperty().c_str();
+            bool ok = false;
+            for (size_t i = 0; i < whitelist_size; ++i) {
+                if (!strcmp(s, target_prop_whitelist[i])) {
+                    ok = true;
+                    break;
+                }
+            }
+            if(!ok) {
+                continue;
+            }
+        }
+        nodes.push_back(anim);
+    }
+
+    return nodes; // pray for NRVO
+}
+
+// ------------------------------------------------------------------------------------------------
+AnimationStack::AnimationStack(uint64_t id, const Element& element, const std::string& name, const Document& doc)
+: Object(id, element, name)
+{
+    const Scope& sc = GetRequiredScope(element);
+
+    // note: we don't currently use any of these properties so we shouldn't bother if it is missing
+    props = GetPropertyTable(doc,"AnimationStack.FbxAnimStack",element,sc, true);
+
+    // resolve attached animation layers
+    const std::vector<const Connection*>& conns = doc.GetConnectionsByDestinationSequenced(ID(),"AnimationLayer");
+    layers.reserve(conns.size());
+
+    for(const Connection* con : conns) {
+
+        // link should not go to a property
+        if (con->PropertyName().length()) {
+            continue;
+        }
+
+        const Object* const ob = con->SourceObject();
+        if(!ob) {
+            DOMWarning("failed to read source object for AnimationLayer->AnimationStack link, ignoring",&element);
+            continue;
+        }
+
+        const AnimationLayer* const anim = dynamic_cast<const AnimationLayer*>(ob);
+        if(!anim) {
+            DOMWarning("source object for ->AnimationStack link is not an AnimationLayer",&element);
+            continue;
+        }
+        layers.push_back(anim);
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+AnimationStack::~AnimationStack()
+{
+    // empty
+}
+
+} //!FBX
+} //!Assimp
+
+#endif // ASSIMP_BUILD_NO_FBX_IMPORTER
diff --git a/thirdparty/assimp/code/FBX/FBXBinaryTokenizer.cpp b/thirdparty/assimp/code/FBX/FBXBinaryTokenizer.cpp
new file mode 100644
index 0000000000..a4a2bc8e79
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXBinaryTokenizer.cpp
@@ -0,0 +1,466 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+/** @file  FBXBinaryTokenizer.cpp
+ *  @brief Implementation of a fake lexer for binary fbx files -
+ *    we emit tokens so the parser needs almost no special handling
+ *    for binary files.
+ */
+
+#ifndef ASSIMP_BUILD_NO_FBX_IMPORTER
+
+#include "FBXTokenizer.h"
+#include "FBXUtil.h"
+#include <assimp/defs.h>
+#include <stdint.h>
+#include <assimp/Exceptional.h>
+#include <assimp/ByteSwapper.h>
+
+namespace Assimp {
+namespace FBX {
+
+//enum Flag
+//{
+//   e_unknown_0 = 1 << 0,
+//   e_unknown_1 = 1 << 1,
+//   e_unknown_2 = 1 << 2,
+//   e_unknown_3 = 1 << 3,
+//   e_unknown_4 = 1 << 4,
+//   e_unknown_5 = 1 << 5,
+//   e_unknown_6 = 1 << 6,
+//   e_unknown_7 = 1 << 7,
+//   e_unknown_8 = 1 << 8,
+//   e_unknown_9 = 1 << 9,
+//   e_unknown_10 = 1 << 10,
+//   e_unknown_11 = 1 << 11,
+//   e_unknown_12 = 1 << 12,
+//   e_unknown_13 = 1 << 13,
+//   e_unknown_14 = 1 << 14,
+//   e_unknown_15 = 1 << 15,
+//   e_unknown_16 = 1 << 16,
+//   e_unknown_17 = 1 << 17,
+//   e_unknown_18 = 1 << 18,
+//   e_unknown_19 = 1 << 19,
+//   e_unknown_20 = 1 << 20,
+//   e_unknown_21 = 1 << 21,
+//   e_unknown_22 = 1 << 22,
+//   e_unknown_23 = 1 << 23,
+//   e_flag_field_size_64_bit = 1 << 24, // Not sure what is
+//   e_unknown_25 = 1 << 25,
+//   e_unknown_26 = 1 << 26,
+//   e_unknown_27 = 1 << 27,
+//   e_unknown_28 = 1 << 28,
+//   e_unknown_29 = 1 << 29,
+//   e_unknown_30 = 1 << 30,
+//   e_unknown_31 = 1 << 31
+//};
+//
+//bool check_flag(uint32_t flags, Flag to_check)
+//{
+//	return (flags & to_check) != 0;
+//}
+// ------------------------------------------------------------------------------------------------
+Token::Token(const char* sbegin, const char* send, TokenType type, size_t offset)
+    :
+    #ifdef DEBUG
+    contents(sbegin, static_cast<size_t>(send-sbegin)),
+    #endif
+    sbegin(sbegin)
+    , send(send)
+    , type(type)
+    , line(offset)
+    , column(BINARY_MARKER)
+{
+    ai_assert(sbegin);
+    ai_assert(send);
+
+    // binary tokens may have zero length because they are sometimes dummies
+    // inserted by TokenizeBinary()
+    ai_assert(send >= sbegin);
+}
+
+
+namespace {
+
+// ------------------------------------------------------------------------------------------------
+// signal tokenization error, this is always unrecoverable. Throws DeadlyImportError.
+AI_WONT_RETURN void TokenizeError(const std::string& message, size_t offset) AI_WONT_RETURN_SUFFIX;
+AI_WONT_RETURN void TokenizeError(const std::string& message, size_t offset)
+{
+    throw DeadlyImportError(Util::AddOffset("FBX-Tokenize",message,offset));
+}
+
+
+// ------------------------------------------------------------------------------------------------
+size_t Offset(const char* begin, const char* cursor) {
+    ai_assert(begin <= cursor);
+
+    return cursor - begin;
+}
+
+// ------------------------------------------------------------------------------------------------
+void TokenizeError(const std::string& message, const char* begin, const char* cursor) {
+    TokenizeError(message, Offset(begin, cursor));
+}
+
+// ------------------------------------------------------------------------------------------------
+uint32_t ReadWord(const char* input, const char*& cursor, const char* end) {
+    const size_t k_to_read = sizeof( uint32_t );
+    if(Offset(cursor, end) < k_to_read ) {
+        TokenizeError("cannot ReadWord, out of bounds",input, cursor);
+    }
+
+    uint32_t word;
+    ::memcpy(&word, cursor, 4);
+    AI_SWAP4(word);
+
+    cursor += k_to_read;
+
+    return word;
+}
+
+// ------------------------------------------------------------------------------------------------
+uint64_t ReadDoubleWord(const char* input, const char*& cursor, const char* end) {
+    const size_t k_to_read = sizeof(uint64_t);
+    if(Offset(cursor, end) < k_to_read) {
+        TokenizeError("cannot ReadDoubleWord, out of bounds",input, cursor);
+    }
+
+    uint64_t dword /*= *reinterpret_cast<const uint64_t*>(cursor)*/;
+    ::memcpy( &dword, cursor, sizeof( uint64_t ) );
+    AI_SWAP8(dword);
+
+    cursor += k_to_read;
+
+    return dword;
+}
+
+// ------------------------------------------------------------------------------------------------
+uint8_t ReadByte(const char* input, const char*& cursor, const char* end) {
+    if(Offset(cursor, end) < sizeof( uint8_t ) ) {
+        TokenizeError("cannot ReadByte, out of bounds",input, cursor);
+    }
+
+    uint8_t word;/* = *reinterpret_cast< const uint8_t* >( cursor )*/
+    ::memcpy( &word, cursor, sizeof( uint8_t ) );
+    ++cursor;
+
+    return word;
+}
+
+// ------------------------------------------------------------------------------------------------
+unsigned int ReadString(const char*& sbegin_out, const char*& send_out, const char* input,
+        const char*& cursor, const char* end, bool long_length = false, bool allow_null = false) {
+    const uint32_t len_len = long_length ? 4 : 1;
+    if(Offset(cursor, end) < len_len) {
+        TokenizeError("cannot ReadString, out of bounds reading length",input, cursor);
+    }
+
+    const uint32_t length = long_length ? ReadWord(input, cursor, end) : ReadByte(input, cursor, end);
+
+    if (Offset(cursor, end) < length) {
+        TokenizeError("cannot ReadString, length is out of bounds",input, cursor);
+    }
+
+    sbegin_out = cursor;
+    cursor += length;
+
+    send_out = cursor;
+
+    if(!allow_null) {
+        for (unsigned int i = 0; i < length; ++i) {
+            if(sbegin_out[i] == '\0') {
+                TokenizeError("failed ReadString, unexpected NUL character in string",input, cursor);
+            }
+        }
+    }
+
+    return length;
+}
+
+// ------------------------------------------------------------------------------------------------
+void ReadData(const char*& sbegin_out, const char*& send_out, const char* input, const char*& cursor, const char* end) {
+    if(Offset(cursor, end) < 1) {
+        TokenizeError("cannot ReadData, out of bounds reading length",input, cursor);
+    }
+
+    const char type = *cursor;
+    sbegin_out = cursor++;
+
+    switch(type)
+    {
+        // 16 bit int
+    case 'Y':
+        cursor += 2;
+        break;
+
+        // 1 bit bool flag (yes/no)
+    case 'C':
+        cursor += 1;
+        break;
+
+        // 32 bit int
+    case 'I':
+        // <- fall through
+
+        // float
+    case 'F':
+        cursor += 4;
+        break;
+
+        // double
+    case 'D':
+        cursor += 8;
+        break;
+
+        // 64 bit int
+    case 'L':
+        cursor += 8;
+        break;
+
+        // note: do not write cursor += ReadWord(...cursor) as this would be UB
+
+        // raw binary data
+    case 'R':
+    {
+        const uint32_t length = ReadWord(input, cursor, end);
+        cursor += length;
+        break;
+    }
+
+    case 'b':
+        // TODO: what is the 'b' type code? Right now we just skip over it /
+        // take the full range we could get
+        cursor = end;
+        break;
+
+        // array of *
+    case 'f':
+    case 'd':
+    case 'l':
+    case 'i':
+    case 'c':   {
+        const uint32_t length = ReadWord(input, cursor, end);
+        const uint32_t encoding = ReadWord(input, cursor, end);
+
+        const uint32_t comp_len = ReadWord(input, cursor, end);
+
+        // compute length based on type and check against the stored value
+        if(encoding == 0) {
+            uint32_t stride = 0;
+            switch(type)
+            {
+            case 'f':
+            case 'i':
+                stride = 4;
+                break;
+
+            case 'd':
+            case 'l':
+                stride = 8;
+                break;
+
+            case 'c':
+                stride = 1;
+                break;
+
+            default:
+                ai_assert(false);
+            };
+            ai_assert(stride > 0);
+            if(length * stride != comp_len) {
+                TokenizeError("cannot ReadData, calculated data stride differs from what the file claims",input, cursor);
+            }
+        }
+        // zip/deflate algorithm (encoding==1)? take given length. anything else? die
+        else if (encoding != 1) {
+            TokenizeError("cannot ReadData, unknown encoding",input, cursor);
+        }
+        cursor += comp_len;
+        break;
+    }
+
+        // string
+    case 'S': {
+        const char* sb, *se;
+        // 0 characters can legally happen in such strings
+        ReadString(sb, se, input, cursor, end, true, true);
+        break;
+    }
+    default:
+        TokenizeError("cannot ReadData, unexpected type code: " + std::string(&type, 1),input, cursor);
+    }
+
+    if(cursor > end) {
+        TokenizeError("cannot ReadData, the remaining size is too small for the data type: " + std::string(&type, 1),input, cursor);
+    }
+
+    // the type code is contained in the returned range
+    send_out = cursor;
+}
+
+
+// ------------------------------------------------------------------------------------------------
+bool ReadScope(TokenList& output_tokens, const char* input, const char*& cursor, const char* end, bool const is64bits)
+{
+    // the first word contains the offset at which this block ends
+	const uint64_t end_offset = is64bits ? ReadDoubleWord(input, cursor, end) : ReadWord(input, cursor, end);
+
+    // we may get 0 if reading reached the end of the file -
+    // fbx files have a mysterious extra footer which I don't know
+    // how to extract any information from, but at least it always
+    // starts with a 0.
+    if(!end_offset) {
+        return false;
+    }
+
+    if(end_offset > Offset(input, end)) {
+        TokenizeError("block offset is out of range",input, cursor);
+    }
+    else if(end_offset < Offset(input, cursor)) {
+        TokenizeError("block offset is negative out of range",input, cursor);
+    }
+
+    // the second data word contains the number of properties in the scope
+	const uint64_t prop_count = is64bits ? ReadDoubleWord(input, cursor, end) : ReadWord(input, cursor, end);
+
+    // the third data word contains the length of the property list
+	const uint64_t prop_length = is64bits ? ReadDoubleWord(input, cursor, end) : ReadWord(input, cursor, end);
+
+    // now comes the name of the scope/key
+    const char* sbeg, *send;
+    ReadString(sbeg, send, input, cursor, end);
+
+    output_tokens.push_back(new_Token(sbeg, send, TokenType_KEY, Offset(input, cursor) ));
+
+    // now come the individual properties
+    const char* begin_cursor = cursor;
+    for (unsigned int i = 0; i < prop_count; ++i) {
+        ReadData(sbeg, send, input, cursor, begin_cursor + prop_length);
+
+        output_tokens.push_back(new_Token(sbeg, send, TokenType_DATA, Offset(input, cursor) ));
+
+        if(i != prop_count-1) {
+            output_tokens.push_back(new_Token(cursor, cursor + 1, TokenType_COMMA, Offset(input, cursor) ));
+        }
+    }
+
+    if (Offset(begin_cursor, cursor) != prop_length) {
+        TokenizeError("property length not reached, something is wrong",input, cursor);
+    }
+
+    // at the end of each nested block, there is a NUL record to indicate
+    // that the sub-scope exists (i.e. to distinguish between P: and P : {})
+    // this NUL record is 13 bytes long on 32 bit version and 25 bytes long on 64 bit.
+	const size_t sentinel_block_length = is64bits ? (sizeof(uint64_t)* 3 + 1) : (sizeof(uint32_t)* 3 + 1);
+
+    if (Offset(input, cursor) < end_offset) {
+        if (end_offset - Offset(input, cursor) < sentinel_block_length) {
+            TokenizeError("insufficient padding bytes at block end",input, cursor);
+        }
+
+        output_tokens.push_back(new_Token(cursor, cursor + 1, TokenType_OPEN_BRACKET, Offset(input, cursor) ));
+
+        // XXX this is vulnerable to stack overflowing ..
+        while(Offset(input, cursor) < end_offset - sentinel_block_length) {
+			ReadScope(output_tokens, input, cursor, input + end_offset - sentinel_block_length, is64bits);
+        }
+        output_tokens.push_back(new_Token(cursor, cursor + 1, TokenType_CLOSE_BRACKET, Offset(input, cursor) ));
+
+        for (unsigned int i = 0; i < sentinel_block_length; ++i) {
+            if(cursor[i] != '\0') {
+                TokenizeError("failed to read nested block sentinel, expected all bytes to be 0",input, cursor);
+            }
+        }
+        cursor += sentinel_block_length;
+    }
+
+    if (Offset(input, cursor) != end_offset) {
+        TokenizeError("scope length not reached, something is wrong",input, cursor);
+    }
+
+    return true;
+}
+
+} // anonymous namespace
+
+// ------------------------------------------------------------------------------------------------
+// TODO: Test FBX Binary files newer than the 7500 version to check if the 64 bits address behaviour is consistent
+void TokenizeBinary(TokenList& output_tokens, const char* input, size_t length)
+{
+    ai_assert(input);
+
+    if(length < 0x1b) {
+        TokenizeError("file is too short",0);
+    }
+
+    //uint32_t offset = 0x15;
+/*    const char* cursor = input + 0x15;
+
+    const uint32_t flags = ReadWord(input, cursor, input + length);
+
+    const uint8_t padding_0 = ReadByte(input, cursor, input + length); // unused
+    const uint8_t padding_1 = ReadByte(input, cursor, input + length); // unused*/
+
+    if (strncmp(input,"Kaydara FBX Binary",18)) {
+        TokenizeError("magic bytes not found",0);
+    }
+
+    const char* cursor = input + 18;
+	/*Result ignored*/ ReadByte(input, cursor, input + length);
+	/*Result ignored*/ ReadByte(input, cursor, input + length);
+	/*Result ignored*/ ReadByte(input, cursor, input + length);
+	/*Result ignored*/ ReadByte(input, cursor, input + length);
+	/*Result ignored*/ ReadByte(input, cursor, input + length);
+	const uint32_t version = ReadWord(input, cursor, input + length);
+	const bool is64bits = version >= 7500;
+    const char *end = input + length;
+    while (cursor < end ) {
+		if (!ReadScope(output_tokens, input, cursor, input + length, is64bits)) {
+            break;
+        }
+    }
+}
+
+} // !FBX
+} // !Assimp
+
+#endif
diff --git a/thirdparty/assimp/code/FBX/FBXCommon.h b/thirdparty/assimp/code/FBX/FBXCommon.h
new file mode 100644
index 0000000000..e516449130
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXCommon.h
@@ -0,0 +1,86 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+copyright notice, this list of conditions and the
+following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other
+materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+contributors may be used to endorse or promote products
+derived from this software without specific prior
+written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file FBXCommon.h
+* Some useful constants and enums for dealing with FBX files.
+*/
+#ifndef AI_FBXCOMMON_H_INC
+#define AI_FBXCOMMON_H_INC
+
+#ifndef ASSIMP_BUILD_NO_FBX_EXPORTER
+
+namespace Assimp {
+namespace FBX
+{
+    const std::string NULL_RECORD = { // 13 null bytes
+        '\0','\0','\0','\0','\0','\0','\0','\0','\0','\0','\0','\0','\0'
+    }; // who knows why
+    const std::string SEPARATOR = {'\x00', '\x01'}; // for use inside strings
+    const std::string MAGIC_NODE_TAG = "_$AssimpFbx$"; // from import
+    const int64_t SECOND = 46186158000; // FBX's kTime unit
+
+    // rotation order. We'll probably use EulerXYZ for everything
+    enum RotOrder {
+        RotOrder_EulerXYZ = 0,
+        RotOrder_EulerXZY,
+        RotOrder_EulerYZX,
+        RotOrder_EulerYXZ,
+        RotOrder_EulerZXY,
+        RotOrder_EulerZYX,
+
+        RotOrder_SphericXYZ,
+
+        RotOrder_MAX // end-of-enum sentinel
+    };
+
+    // transformation inheritance method. Most of the time RSrs
+    enum TransformInheritance {
+        TransformInheritance_RrSs = 0,
+        TransformInheritance_RSrs,
+        TransformInheritance_Rrs,
+
+        TransformInheritance_MAX // end-of-enum sentinel
+    };
+}
+}
+#endif // ASSIMP_BUILD_NO_FBX_EXPORTER
+
+#endif // AI_FBXCOMMON_H_INC
diff --git a/thirdparty/assimp/code/FBX/FBXCompileConfig.h b/thirdparty/assimp/code/FBX/FBXCompileConfig.h
new file mode 100644
index 0000000000..3a3841fa5b
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXCompileConfig.h
@@ -0,0 +1,70 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXCompileConfig.h
+ *  @brief FBX importer compile-time switches
+ */
+#ifndef INCLUDED_AI_FBX_COMPILECONFIG_H
+#define INCLUDED_AI_FBX_COMPILECONFIG_H
+
+#include <map>
+
+//
+#if _MSC_VER > 1500 || (defined __GNUC___)
+#   define ASSIMP_FBX_USE_UNORDERED_MULTIMAP
+#   else
+#   define fbx_unordered_map map
+#   define fbx_unordered_multimap multimap
+#endif
+
+#ifdef ASSIMP_FBX_USE_UNORDERED_MULTIMAP
+#   include <unordered_map>
+#   if _MSC_VER > 1600
+#       define fbx_unordered_map unordered_map
+#       define fbx_unordered_multimap unordered_multimap
+#   else
+#       define fbx_unordered_map tr1::unordered_map
+#       define fbx_unordered_multimap tr1::unordered_multimap
+#   endif
+#endif
+
+#endif // INCLUDED_AI_FBX_COMPILECONFIG_H
diff --git a/thirdparty/assimp/code/FBX/FBXConverter.cpp b/thirdparty/assimp/code/FBX/FBXConverter.cpp
new file mode 100644
index 0000000000..9f940d3226
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXConverter.cpp
@@ -0,0 +1,3636 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXConverter.cpp
+ *  @brief Implementation of the FBX DOM -> aiScene converter
+ */
+
+#ifndef ASSIMP_BUILD_NO_FBX_IMPORTER
+
+#include "FBXConverter.h"
+#include "FBXParser.h"
+#include "FBXMeshGeometry.h"
+#include "FBXDocument.h"
+#include "FBXUtil.h"
+#include "FBXProperties.h"
+#include "FBXImporter.h"
+
+#include <assimp/StringComparison.h>
+
+#include <assimp/scene.h>
+
+#include <assimp/CreateAnimMesh.h>
+
+#include <tuple>
+#include <memory>
+#include <iterator>
+#include <vector>
+#include <sstream>
+#include <iomanip>
+
+
+namespace Assimp {
+    namespace FBX {
+
+        using namespace Util;
+
+#define MAGIC_NODE_TAG "_$AssimpFbx$"
+
+#define CONVERT_FBX_TIME(time) static_cast<double>(time) / 46186158000L
+
+        FBXConverter::FBXConverter(aiScene* out, const Document& doc, bool removeEmptyBones, FbxUnit unit )
+        : defaultMaterialIndex()
+        , lights()
+        , cameras()
+        , textures()
+        , materials_converted()
+        , textures_converted()
+        , meshes_converted()
+        , node_anim_chain_bits()
+        , mNodeNames()
+        , anim_fps()
+        , out(out)
+        , doc(doc)
+        , mRemoveEmptyBones( removeEmptyBones )
+        , mCurrentUnit(FbxUnit::cm) {
+            // animations need to be converted first since this will
+            // populate the node_anim_chain_bits map, which is needed
+            // to determine which nodes need to be generated.
+            ConvertAnimations();
+            ConvertRootNode();
+
+            if (doc.Settings().readAllMaterials) {
+                // unfortunately this means we have to evaluate all objects
+                for (const ObjectMap::value_type& v : doc.Objects()) {
+
+                    const Object* ob = v.second->Get();
+                    if (!ob) {
+                        continue;
+                    }
+
+                    const Material* mat = dynamic_cast<const Material*>(ob);
+                    if (mat) {
+
+                        if (materials_converted.find(mat) == materials_converted.end()) {
+                            ConvertMaterial(*mat, 0);
+                        }
+                    }
+                }
+            }
+
+            ConvertGlobalSettings();
+            TransferDataToScene();
+            ConvertToUnitScale(unit);
+
+            // if we didn't read any meshes set the AI_SCENE_FLAGS_INCOMPLETE
+            // to make sure the scene passes assimp's validation. FBX files
+            // need not contain geometry (i.e. camera animations, raw armatures).
+            if (out->mNumMeshes == 0) {
+                out->mFlags |= AI_SCENE_FLAGS_INCOMPLETE;
+            }
+        }
+
+
+        FBXConverter::~FBXConverter() {
+            std::for_each(meshes.begin(), meshes.end(), Util::delete_fun<aiMesh>());
+            std::for_each(materials.begin(), materials.end(), Util::delete_fun<aiMaterial>());
+            std::for_each(animations.begin(), animations.end(), Util::delete_fun<aiAnimation>());
+            std::for_each(lights.begin(), lights.end(), Util::delete_fun<aiLight>());
+            std::for_each(cameras.begin(), cameras.end(), Util::delete_fun<aiCamera>());
+            std::for_each(textures.begin(), textures.end(), Util::delete_fun<aiTexture>());
+        }
+
+        void FBXConverter::ConvertRootNode() {
+            out->mRootNode = new aiNode();
+            std::string unique_name;
+            GetUniqueName("RootNode", unique_name);
+            out->mRootNode->mName.Set(unique_name);
+
+            // root has ID 0
+            ConvertNodes(0L, *out->mRootNode);
+        }
+
+        static std::string getAncestorBaseName(const aiNode* node)
+        {
+            const char* nodeName = nullptr;
+            size_t length = 0;
+            while (node && (!nodeName || length == 0))
+            {
+                nodeName = node->mName.C_Str();
+                length = node->mName.length;
+                node = node->mParent;
+            }
+
+            if (!nodeName || length == 0)
+            {
+                return {};
+            }
+            // could be std::string_view if c++17 available
+            return std::string(nodeName, length);
+        }
+
+        // Make unique name
+        std::string FBXConverter::MakeUniqueNodeName(const Model* const model, const aiNode& parent)
+        {
+            std::string original_name = FixNodeName(model->Name());
+            if (original_name.empty())
+            {
+                original_name = getAncestorBaseName(&parent);
+            }
+            std::string unique_name;
+            GetUniqueName(original_name, unique_name);
+            return unique_name;
+        }
+
+        void FBXConverter::ConvertNodes(uint64_t id, aiNode& parent, const aiMatrix4x4& parent_transform) {
+            const std::vector<const Connection*>& conns = doc.GetConnectionsByDestinationSequenced(id, "Model");
+
+            std::vector<aiNode*> nodes;
+            nodes.reserve(conns.size());
+
+            std::vector<aiNode*> nodes_chain;
+            std::vector<aiNode*> post_nodes_chain;
+
+            try {
+                for (const Connection* con : conns) {
+
+                    // ignore object-property links
+                    if (con->PropertyName().length()) {
+                        continue;
+                    }
+
+                    const Object* const object = con->SourceObject();
+                    if (nullptr == object) {
+                        FBXImporter::LogWarn("failed to convert source object for Model link");
+                        continue;
+                    }
+
+                    const Model* const model = dynamic_cast<const Model*>(object);
+
+                    if (nullptr != model) {
+                        nodes_chain.clear();
+                        post_nodes_chain.clear();
+
+                        aiMatrix4x4 new_abs_transform = parent_transform;
+
+                        std::string unique_name = MakeUniqueNodeName(model, parent);
+
+                        // even though there is only a single input node, the design of
+                        // assimp (or rather: the complicated transformation chain that
+                        // is employed by fbx) means that we may need multiple aiNode's
+                        // to represent a fbx node's transformation.
+                        const bool need_additional_node = GenerateTransformationNodeChain(*model, unique_name, nodes_chain, post_nodes_chain);
+
+                        ai_assert(nodes_chain.size());
+
+                        if (need_additional_node) {
+                            nodes_chain.push_back(new aiNode(unique_name));
+                        }
+
+                        //setup metadata on newest node
+                        SetupNodeMetadata(*model, *nodes_chain.back());
+
+                        // link all nodes in a row
+                        aiNode* last_parent = &parent;
+                        for (aiNode* prenode : nodes_chain) {
+                            ai_assert(prenode);
+
+                            if (last_parent != &parent) {
+                                last_parent->mNumChildren = 1;
+                                last_parent->mChildren = new aiNode*[1];
+                                last_parent->mChildren[0] = prenode;
+                            }
+
+                            prenode->mParent = last_parent;
+                            last_parent = prenode;
+
+                            new_abs_transform *= prenode->mTransformation;
+                        }
+
+                        // attach geometry
+                        ConvertModel(*model, *nodes_chain.back(), new_abs_transform);
+
+                        // check if there will be any child nodes
+                        const std::vector<const Connection*>& child_conns
+                            = doc.GetConnectionsByDestinationSequenced(model->ID(), "Model");
+
+                        // if so, link the geometric transform inverse nodes
+                        // before we attach any child nodes
+                        if (child_conns.size()) {
+                            for (aiNode* postnode : post_nodes_chain) {
+                                ai_assert(postnode);
+
+                                if (last_parent != &parent) {
+                                    last_parent->mNumChildren = 1;
+                                    last_parent->mChildren = new aiNode*[1];
+                                    last_parent->mChildren[0] = postnode;
+                                }
+
+                                postnode->mParent = last_parent;
+                                last_parent = postnode;
+
+                                new_abs_transform *= postnode->mTransformation;
+                            }
+                        }
+                        else {
+                            // free the nodes we allocated as we don't need them
+                            Util::delete_fun<aiNode> deleter;
+                            std::for_each(
+                                post_nodes_chain.begin(),
+                                post_nodes_chain.end(),
+                                deleter
+                            );
+                        }
+
+                        // attach sub-nodes (if any)
+                        ConvertNodes(model->ID(), *last_parent, new_abs_transform);
+
+                        if (doc.Settings().readLights) {
+                            ConvertLights(*model, unique_name);
+                        }
+
+                        if (doc.Settings().readCameras) {
+                            ConvertCameras(*model, unique_name);
+                        }
+
+                        nodes.push_back(nodes_chain.front());
+                        nodes_chain.clear();
+                    }
+                }
+
+                if (nodes.size()) {
+                    parent.mChildren = new aiNode*[nodes.size()]();
+                    parent.mNumChildren = static_cast<unsigned int>(nodes.size());
+
+                    std::swap_ranges(nodes.begin(), nodes.end(), parent.mChildren);
+                }
+            }
+            catch (std::exception&) {
+                Util::delete_fun<aiNode> deleter;
+                std::for_each(nodes.begin(), nodes.end(), deleter);
+                std::for_each(nodes_chain.begin(), nodes_chain.end(), deleter);
+                std::for_each(post_nodes_chain.begin(), post_nodes_chain.end(), deleter);
+            }
+        }
+
+
+        void FBXConverter::ConvertLights(const Model& model, const std::string &orig_name) {
+            const std::vector<const NodeAttribute*>& node_attrs = model.GetAttributes();
+            for (const NodeAttribute* attr : node_attrs) {
+                const Light* const light = dynamic_cast<const Light*>(attr);
+                if (light) {
+                    ConvertLight(*light, orig_name);
+                }
+            }
+        }
+
+        void FBXConverter::ConvertCameras(const Model& model, const std::string &orig_name) {
+            const std::vector<const NodeAttribute*>& node_attrs = model.GetAttributes();
+            for (const NodeAttribute* attr : node_attrs) {
+                const Camera* const cam = dynamic_cast<const Camera*>(attr);
+                if (cam) {
+                    ConvertCamera(*cam, orig_name);
+                }
+            }
+        }
+
+        void FBXConverter::ConvertLight(const Light& light, const std::string &orig_name) {
+            lights.push_back(new aiLight());
+            aiLight* const out_light = lights.back();
+
+            out_light->mName.Set(orig_name);
+
+            const float intensity = light.Intensity() / 100.0f;
+            const aiVector3D& col = light.Color();
+
+            out_light->mColorDiffuse = aiColor3D(col.x, col.y, col.z);
+            out_light->mColorDiffuse.r *= intensity;
+            out_light->mColorDiffuse.g *= intensity;
+            out_light->mColorDiffuse.b *= intensity;
+
+            out_light->mColorSpecular = out_light->mColorDiffuse;
+
+            //lights are defined along negative y direction
+            out_light->mPosition = aiVector3D(0.0f);
+            out_light->mDirection = aiVector3D(0.0f, -1.0f, 0.0f);
+            out_light->mUp = aiVector3D(0.0f, 0.0f, -1.0f);
+
+            switch (light.LightType())
+            {
+            case Light::Type_Point:
+                out_light->mType = aiLightSource_POINT;
+                break;
+
+            case Light::Type_Directional:
+                out_light->mType = aiLightSource_DIRECTIONAL;
+                break;
+
+            case Light::Type_Spot:
+                out_light->mType = aiLightSource_SPOT;
+                out_light->mAngleOuterCone = AI_DEG_TO_RAD(light.OuterAngle());
+                out_light->mAngleInnerCone = AI_DEG_TO_RAD(light.InnerAngle());
+                break;
+
+            case Light::Type_Area:
+                FBXImporter::LogWarn("cannot represent area light, set to UNDEFINED");
+                out_light->mType = aiLightSource_UNDEFINED;
+                break;
+
+            case Light::Type_Volume:
+                FBXImporter::LogWarn("cannot represent volume light, set to UNDEFINED");
+                out_light->mType = aiLightSource_UNDEFINED;
+                break;
+            default:
+                ai_assert(false);
+            }
+
+            float decay = light.DecayStart();
+            switch (light.DecayType())
+            {
+            case Light::Decay_None:
+                out_light->mAttenuationConstant = decay;
+                out_light->mAttenuationLinear = 0.0f;
+                out_light->mAttenuationQuadratic = 0.0f;
+                break;
+            case Light::Decay_Linear:
+                out_light->mAttenuationConstant = 0.0f;
+                out_light->mAttenuationLinear = 2.0f / decay;
+                out_light->mAttenuationQuadratic = 0.0f;
+                break;
+            case Light::Decay_Quadratic:
+                out_light->mAttenuationConstant = 0.0f;
+                out_light->mAttenuationLinear = 0.0f;
+                out_light->mAttenuationQuadratic = 2.0f / (decay * decay);
+                break;
+            case Light::Decay_Cubic:
+                FBXImporter::LogWarn("cannot represent cubic attenuation, set to Quadratic");
+                out_light->mAttenuationQuadratic = 1.0f;
+                break;
+            default:
+                ai_assert(false);
+                break;
+            }
+        }
+
+        void FBXConverter::ConvertCamera(const Camera& cam, const std::string &orig_name)
+        {
+            cameras.push_back(new aiCamera());
+            aiCamera* const out_camera = cameras.back();
+
+            out_camera->mName.Set(orig_name);
+
+            out_camera->mAspect = cam.AspectWidth() / cam.AspectHeight();
+
+            out_camera->mPosition = aiVector3D(0.0f);
+            out_camera->mLookAt = aiVector3D(1.0f, 0.0f, 0.0f);
+            out_camera->mUp = aiVector3D(0.0f, 1.0f, 0.0f);
+
+            out_camera->mHorizontalFOV = AI_DEG_TO_RAD(cam.FieldOfView());
+
+            out_camera->mClipPlaneNear = cam.NearPlane();
+            out_camera->mClipPlaneFar = cam.FarPlane();
+
+            out_camera->mHorizontalFOV = AI_DEG_TO_RAD(cam.FieldOfView());
+            out_camera->mClipPlaneNear = cam.NearPlane();
+            out_camera->mClipPlaneFar = cam.FarPlane();
+        }
+
+        void FBXConverter::GetUniqueName(const std::string &name, std::string &uniqueName)
+        {
+            uniqueName = name;
+            auto it_pair = mNodeNames.insert({ name, 0 }); // duplicate node name instance count
+            unsigned int& i = it_pair.first->second;
+            while (!it_pair.second)
+            {
+                i++;
+                std::ostringstream ext;
+                ext << name << std::setfill('0') << std::setw(3) << i;
+                uniqueName = ext.str();
+                it_pair = mNodeNames.insert({ uniqueName, 0 });
+            }
+        }
+
+        const char* FBXConverter::NameTransformationComp(TransformationComp comp) {
+            switch (comp) {
+            case TransformationComp_Translation:
+                return "Translation";
+            case TransformationComp_RotationOffset:
+                return "RotationOffset";
+            case TransformationComp_RotationPivot:
+                return "RotationPivot";
+            case TransformationComp_PreRotation:
+                return "PreRotation";
+            case TransformationComp_Rotation:
+                return "Rotation";
+            case TransformationComp_PostRotation:
+                return "PostRotation";
+            case TransformationComp_RotationPivotInverse:
+                return "RotationPivotInverse";
+            case TransformationComp_ScalingOffset:
+                return "ScalingOffset";
+            case TransformationComp_ScalingPivot:
+                return "ScalingPivot";
+            case TransformationComp_Scaling:
+                return "Scaling";
+            case TransformationComp_ScalingPivotInverse:
+                return "ScalingPivotInverse";
+            case TransformationComp_GeometricScaling:
+                return "GeometricScaling";
+            case TransformationComp_GeometricRotation:
+                return "GeometricRotation";
+            case TransformationComp_GeometricTranslation:
+                return "GeometricTranslation";
+            case TransformationComp_GeometricScalingInverse:
+                return "GeometricScalingInverse";
+            case TransformationComp_GeometricRotationInverse:
+                return "GeometricRotationInverse";
+            case TransformationComp_GeometricTranslationInverse:
+                return "GeometricTranslationInverse";
+            case TransformationComp_MAXIMUM: // this is to silence compiler warnings
+            default:
+                break;
+            }
+
+            ai_assert(false);
+
+            return nullptr;
+        }
+
+        const char* FBXConverter::NameTransformationCompProperty(TransformationComp comp) {
+            switch (comp) {
+            case TransformationComp_Translation:
+                return "Lcl Translation";
+            case TransformationComp_RotationOffset:
+                return "RotationOffset";
+            case TransformationComp_RotationPivot:
+                return "RotationPivot";
+            case TransformationComp_PreRotation:
+                return "PreRotation";
+            case TransformationComp_Rotation:
+                return "Lcl Rotation";
+            case TransformationComp_PostRotation:
+                return "PostRotation";
+            case TransformationComp_RotationPivotInverse:
+                return "RotationPivotInverse";
+            case TransformationComp_ScalingOffset:
+                return "ScalingOffset";
+            case TransformationComp_ScalingPivot:
+                return "ScalingPivot";
+            case TransformationComp_Scaling:
+                return "Lcl Scaling";
+            case TransformationComp_ScalingPivotInverse:
+                return "ScalingPivotInverse";
+            case TransformationComp_GeometricScaling:
+                return "GeometricScaling";
+            case TransformationComp_GeometricRotation:
+                return "GeometricRotation";
+            case TransformationComp_GeometricTranslation:
+                return "GeometricTranslation";
+            case TransformationComp_GeometricScalingInverse:
+                return "GeometricScalingInverse";
+            case TransformationComp_GeometricRotationInverse:
+                return "GeometricRotationInverse";
+            case TransformationComp_GeometricTranslationInverse:
+                return "GeometricTranslationInverse";
+            case TransformationComp_MAXIMUM: // this is to silence compiler warnings
+                break;
+            }
+
+            ai_assert(false);
+
+            return nullptr;
+        }
+
+        aiVector3D FBXConverter::TransformationCompDefaultValue(TransformationComp comp)
+        {
+            // XXX a neat way to solve the never-ending special cases for scaling
+            // would be to do everything in log space!
+            return comp == TransformationComp_Scaling ? aiVector3D(1.f, 1.f, 1.f) : aiVector3D();
+        }
+
+        void FBXConverter::GetRotationMatrix(Model::RotOrder mode, const aiVector3D& rotation, aiMatrix4x4& out)
+        {
+            if (mode == Model::RotOrder_SphericXYZ) {
+                FBXImporter::LogError("Unsupported RotationMode: SphericXYZ");
+                out = aiMatrix4x4();
+                return;
+            }
+
+            const float angle_epsilon = 1e-6f;
+
+            out = aiMatrix4x4();
+
+            bool is_id[3] = { true, true, true };
+
+            aiMatrix4x4 temp[3];
+            if (std::fabs(rotation.z) > angle_epsilon) {
+                aiMatrix4x4::RotationZ(AI_DEG_TO_RAD(rotation.z), temp[2]);
+                is_id[2] = false;
+            }
+            if (std::fabs(rotation.y) > angle_epsilon) {
+                aiMatrix4x4::RotationY(AI_DEG_TO_RAD(rotation.y), temp[1]);
+                is_id[1] = false;
+            }
+            if (std::fabs(rotation.x) > angle_epsilon) {
+                aiMatrix4x4::RotationX(AI_DEG_TO_RAD(rotation.x), temp[0]);
+                is_id[0] = false;
+            }
+
+            int order[3] = { -1, -1, -1 };
+
+            // note: rotation order is inverted since we're left multiplying as is usual in assimp
+            switch (mode)
+            {
+            case Model::RotOrder_EulerXYZ:
+                order[0] = 2;
+                order[1] = 1;
+                order[2] = 0;
+                break;
+
+            case Model::RotOrder_EulerXZY:
+                order[0] = 1;
+                order[1] = 2;
+                order[2] = 0;
+                break;
+
+            case Model::RotOrder_EulerYZX:
+                order[0] = 0;
+                order[1] = 2;
+                order[2] = 1;
+                break;
+
+            case Model::RotOrder_EulerYXZ:
+                order[0] = 2;
+                order[1] = 0;
+                order[2] = 1;
+                break;
+
+            case Model::RotOrder_EulerZXY:
+                order[0] = 1;
+                order[1] = 0;
+                order[2] = 2;
+                break;
+
+            case Model::RotOrder_EulerZYX:
+                order[0] = 0;
+                order[1] = 1;
+                order[2] = 2;
+                break;
+
+            default:
+                ai_assert(false);
+                break;
+            }
+
+            ai_assert(order[0] >= 0);
+            ai_assert(order[0] <= 2);
+            ai_assert(order[1] >= 0);
+            ai_assert(order[1] <= 2);
+            ai_assert(order[2] >= 0);
+            ai_assert(order[2] <= 2);
+
+            if (!is_id[order[0]]) {
+                out = temp[order[0]];
+            }
+
+            if (!is_id[order[1]]) {
+                out = out * temp[order[1]];
+            }
+
+            if (!is_id[order[2]]) {
+                out = out * temp[order[2]];
+            }
+        }
+
+        bool FBXConverter::NeedsComplexTransformationChain(const Model& model)
+        {
+            const PropertyTable& props = model.Props();
+            bool ok;
+
+            const float zero_epsilon = 1e-6f;
+            const aiVector3D all_ones(1.0f, 1.0f, 1.0f);
+            for (size_t i = 0; i < TransformationComp_MAXIMUM; ++i) {
+                const TransformationComp comp = static_cast<TransformationComp>(i);
+
+                if (comp == TransformationComp_Rotation || comp == TransformationComp_Scaling || comp == TransformationComp_Translation) {
+                    continue;
+                }
+
+                bool scale_compare = (comp == TransformationComp_GeometricScaling || comp == TransformationComp_Scaling);
+
+                const aiVector3D& v = PropertyGet<aiVector3D>(props, NameTransformationCompProperty(comp), ok);
+                if (ok && scale_compare) {
+                    if ((v - all_ones).SquareLength() > zero_epsilon) {
+                        return true;
+                    }
+                } else if (ok) {
+                    if (v.SquareLength() > zero_epsilon) {
+                        return true;
+                    }
+                }
+            }
+
+            return false;
+        }
+
+        std::string FBXConverter::NameTransformationChainNode(const std::string& name, TransformationComp comp)
+        {
+            return name + std::string(MAGIC_NODE_TAG) + "_" + NameTransformationComp(comp);
+        }
+
+        bool FBXConverter::GenerateTransformationNodeChain(const Model& model, const std::string& name, std::vector<aiNode*>& output_nodes,
+            std::vector<aiNode*>& post_output_nodes) {
+            const PropertyTable& props = model.Props();
+            const Model::RotOrder rot = model.RotationOrder();
+
+            bool ok;
+
+            aiMatrix4x4 chain[TransformationComp_MAXIMUM];
+            std::fill_n(chain, static_cast<unsigned int>(TransformationComp_MAXIMUM), aiMatrix4x4());
+
+            // generate transformation matrices for all the different transformation components
+            const float zero_epsilon = 1e-6f;
+            const aiVector3D all_ones(1.0f, 1.0f, 1.0f);
+            bool is_complex = false;
+
+            const aiVector3D& PreRotation = PropertyGet<aiVector3D>(props, "PreRotation", ok);
+            if (ok && PreRotation.SquareLength() > zero_epsilon) {
+                is_complex = true;
+
+                GetRotationMatrix(Model::RotOrder::RotOrder_EulerXYZ, PreRotation, chain[TransformationComp_PreRotation]);
+            }
+
+            const aiVector3D& PostRotation = PropertyGet<aiVector3D>(props, "PostRotation", ok);
+            if (ok && PostRotation.SquareLength() > zero_epsilon) {
+                is_complex = true;
+
+                GetRotationMatrix(Model::RotOrder::RotOrder_EulerXYZ, PostRotation, chain[TransformationComp_PostRotation]);
+            }
+
+            const aiVector3D& RotationPivot = PropertyGet<aiVector3D>(props, "RotationPivot", ok);
+            if (ok && RotationPivot.SquareLength() > zero_epsilon) {
+                is_complex = true;
+
+                aiMatrix4x4::Translation(RotationPivot, chain[TransformationComp_RotationPivot]);
+                aiMatrix4x4::Translation(-RotationPivot, chain[TransformationComp_RotationPivotInverse]);
+            }
+
+            const aiVector3D& RotationOffset = PropertyGet<aiVector3D>(props, "RotationOffset", ok);
+            if (ok && RotationOffset.SquareLength() > zero_epsilon) {
+                is_complex = true;
+
+                aiMatrix4x4::Translation(RotationOffset, chain[TransformationComp_RotationOffset]);
+            }
+
+            const aiVector3D& ScalingOffset = PropertyGet<aiVector3D>(props, "ScalingOffset", ok);
+            if (ok && ScalingOffset.SquareLength() > zero_epsilon) {
+                is_complex = true;
+
+                aiMatrix4x4::Translation(ScalingOffset, chain[TransformationComp_ScalingOffset]);
+            }
+
+            const aiVector3D& ScalingPivot = PropertyGet<aiVector3D>(props, "ScalingPivot", ok);
+            if (ok && ScalingPivot.SquareLength() > zero_epsilon) {
+                is_complex = true;
+
+                aiMatrix4x4::Translation(ScalingPivot, chain[TransformationComp_ScalingPivot]);
+                aiMatrix4x4::Translation(-ScalingPivot, chain[TransformationComp_ScalingPivotInverse]);
+            }
+
+            const aiVector3D& Translation = PropertyGet<aiVector3D>(props, "Lcl Translation", ok);
+            if (ok && Translation.SquareLength() > zero_epsilon) {
+                aiMatrix4x4::Translation(Translation, chain[TransformationComp_Translation]);
+            }
+
+            const aiVector3D& Scaling = PropertyGet<aiVector3D>(props, "Lcl Scaling", ok);
+            if (ok && (Scaling - all_ones).SquareLength() > zero_epsilon) {
+                aiMatrix4x4::Scaling(Scaling, chain[TransformationComp_Scaling]);
+            }
+
+            const aiVector3D& Rotation = PropertyGet<aiVector3D>(props, "Lcl Rotation", ok);
+            if (ok && Rotation.SquareLength() > zero_epsilon) {
+                GetRotationMatrix(rot, Rotation, chain[TransformationComp_Rotation]);
+            }
+
+            const aiVector3D& GeometricScaling = PropertyGet<aiVector3D>(props, "GeometricScaling", ok);
+            if (ok && (GeometricScaling - all_ones).SquareLength() > zero_epsilon) {
+                is_complex = true;
+                aiMatrix4x4::Scaling(GeometricScaling, chain[TransformationComp_GeometricScaling]);
+                aiVector3D GeometricScalingInverse = GeometricScaling;
+                bool canscale = true;
+                for (unsigned int i = 0; i < 3; ++i) {
+                    if (std::fabs(GeometricScalingInverse[i]) > zero_epsilon) {
+                        GeometricScalingInverse[i] = 1.0f / GeometricScaling[i];
+                    }
+                    else {
+                        FBXImporter::LogError("cannot invert geometric scaling matrix with a 0.0 scale component");
+                        canscale = false;
+                        break;
+                    }
+                }
+                if (canscale) {
+                    aiMatrix4x4::Scaling(GeometricScalingInverse, chain[TransformationComp_GeometricScalingInverse]);
+                }
+            }
+
+            const aiVector3D& GeometricRotation = PropertyGet<aiVector3D>(props, "GeometricRotation", ok);
+            if (ok && GeometricRotation.SquareLength() > zero_epsilon) {
+                is_complex = true;
+                GetRotationMatrix(rot, GeometricRotation, chain[TransformationComp_GeometricRotation]);
+                GetRotationMatrix(rot, GeometricRotation, chain[TransformationComp_GeometricRotationInverse]);
+                chain[TransformationComp_GeometricRotationInverse].Inverse();
+            }
+
+            const aiVector3D& GeometricTranslation = PropertyGet<aiVector3D>(props, "GeometricTranslation", ok);
+            if (ok && GeometricTranslation.SquareLength() > zero_epsilon) {
+                is_complex = true;
+                aiMatrix4x4::Translation(GeometricTranslation, chain[TransformationComp_GeometricTranslation]);
+                aiMatrix4x4::Translation(-GeometricTranslation, chain[TransformationComp_GeometricTranslationInverse]);
+            }
+
+            // is_complex needs to be consistent with NeedsComplexTransformationChain()
+            // or the interplay between this code and the animation converter would
+            // not be guaranteed.
+            ai_assert(NeedsComplexTransformationChain(model) == is_complex);
+
+            // now, if we have more than just Translation, Scaling and Rotation,
+            // we need to generate a full node chain to accommodate for assimp's
+            // lack to express pivots and offsets.
+            if (is_complex && doc.Settings().preservePivots) {
+                FBXImporter::LogInfo("generating full transformation chain for node: " + name);
+
+                // query the anim_chain_bits dictionary to find out which chain elements
+                // have associated node animation channels. These can not be dropped
+                // even if they have identity transform in bind pose.
+                NodeAnimBitMap::const_iterator it = node_anim_chain_bits.find(name);
+                const unsigned int anim_chain_bitmask = (it == node_anim_chain_bits.end() ? 0 : (*it).second);
+
+                unsigned int bit = 0x1;
+                for (size_t i = 0; i < TransformationComp_MAXIMUM; ++i, bit <<= 1) {
+                    const TransformationComp comp = static_cast<TransformationComp>(i);
+
+                    if (chain[i].IsIdentity() && (anim_chain_bitmask & bit) == 0) {
+                        continue;
+                    }
+
+                    if (comp == TransformationComp_PostRotation) {
+                        chain[i] = chain[i].Inverse();
+                    }
+
+                    aiNode* nd = new aiNode();
+                    nd->mName.Set(NameTransformationChainNode(name, comp));
+                    nd->mTransformation = chain[i];
+
+                    // geometric inverses go in a post-node chain
+                    if (comp == TransformationComp_GeometricScalingInverse ||
+                        comp == TransformationComp_GeometricRotationInverse ||
+                        comp == TransformationComp_GeometricTranslationInverse
+                        ) {
+                        post_output_nodes.push_back(nd);
+                    }
+                    else {
+                        output_nodes.push_back(nd);
+                    }
+                }
+
+                ai_assert(output_nodes.size());
+                return true;
+            }
+
+            // else, we can just multiply the matrices together
+            aiNode* nd = new aiNode();
+            output_nodes.push_back(nd);
+
+            // name passed to the method is already unique
+            nd->mName.Set(name);
+
+            for (const auto &transform : chain) {
+                nd->mTransformation = nd->mTransformation * transform;
+            }
+            return false;
+        }
+
+        void FBXConverter::SetupNodeMetadata(const Model& model, aiNode& nd)
+        {
+            const PropertyTable& props = model.Props();
+            DirectPropertyMap unparsedProperties = props.GetUnparsedProperties();
+
+            // create metadata on node
+            const std::size_t numStaticMetaData = 2;
+            aiMetadata* data = aiMetadata::Alloc(static_cast<unsigned int>(unparsedProperties.size() + numStaticMetaData));
+            nd.mMetaData = data;
+            int index = 0;
+
+            // find user defined properties (3ds Max)
+            data->Set(index++, "UserProperties", aiString(PropertyGet<std::string>(props, "UDP3DSMAX", "")));
+            // preserve the info that a node was marked as Null node in the original file.
+            data->Set(index++, "IsNull", model.IsNull() ? true : false);
+
+            // add unparsed properties to the node's metadata
+            for (const DirectPropertyMap::value_type& prop : unparsedProperties) {
+                // Interpret the property as a concrete type
+                if (const TypedProperty<bool>* interpreted = prop.second->As<TypedProperty<bool> >()) {
+                    data->Set(index++, prop.first, interpreted->Value());
+                }
+                else if (const TypedProperty<int>* interpreted = prop.second->As<TypedProperty<int> >()) {
+                    data->Set(index++, prop.first, interpreted->Value());
+                }
+                else if (const TypedProperty<uint64_t>* interpreted = prop.second->As<TypedProperty<uint64_t> >()) {
+                    data->Set(index++, prop.first, interpreted->Value());
+                }
+                else if (const TypedProperty<float>* interpreted = prop.second->As<TypedProperty<float> >()) {
+                    data->Set(index++, prop.first, interpreted->Value());
+                }
+                else if (const TypedProperty<std::string>* interpreted = prop.second->As<TypedProperty<std::string> >()) {
+                    data->Set(index++, prop.first, aiString(interpreted->Value()));
+                }
+                else if (const TypedProperty<aiVector3D>* interpreted = prop.second->As<TypedProperty<aiVector3D> >()) {
+                    data->Set(index++, prop.first, interpreted->Value());
+                }
+                else {
+                    ai_assert(false);
+                }
+            }
+        }
+
+        void FBXConverter::ConvertModel(const Model& model, aiNode& nd, const aiMatrix4x4& node_global_transform)
+        {
+            const std::vector<const Geometry*>& geos = model.GetGeometry();
+
+            std::vector<unsigned int> meshes;
+            meshes.reserve(geos.size());
+
+            for (const Geometry* geo : geos) {
+
+                const MeshGeometry* const mesh = dynamic_cast<const MeshGeometry*>(geo);
+                const LineGeometry* const line = dynamic_cast<const LineGeometry*>(geo);
+                if (mesh) {
+                    const std::vector<unsigned int>& indices = ConvertMesh(*mesh, model, node_global_transform, nd);
+                    std::copy(indices.begin(), indices.end(), std::back_inserter(meshes));
+                }
+                else if (line) {
+                    const std::vector<unsigned int>& indices = ConvertLine(*line, model, node_global_transform, nd);
+                    std::copy(indices.begin(), indices.end(), std::back_inserter(meshes));
+                }
+                else {
+                    FBXImporter::LogWarn("ignoring unrecognized geometry: " + geo->Name());
+                }
+            }
+
+            if (meshes.size()) {
+                nd.mMeshes = new unsigned int[meshes.size()]();
+                nd.mNumMeshes = static_cast<unsigned int>(meshes.size());
+
+                std::swap_ranges(meshes.begin(), meshes.end(), nd.mMeshes);
+            }
+        }
+
+        std::vector<unsigned int> FBXConverter::ConvertMesh(const MeshGeometry& mesh, const Model& model,
+            const aiMatrix4x4& node_global_transform, aiNode& nd)
+        {
+            std::vector<unsigned int> temp;
+
+            MeshMap::const_iterator it = meshes_converted.find(&mesh);
+            if (it != meshes_converted.end()) {
+                std::copy((*it).second.begin(), (*it).second.end(), std::back_inserter(temp));
+                return temp;
+            }
+
+            const std::vector<aiVector3D>& vertices = mesh.GetVertices();
+            const std::vector<unsigned int>& faces = mesh.GetFaceIndexCounts();
+            if (vertices.empty() || faces.empty()) {
+                FBXImporter::LogWarn("ignoring empty geometry: " + mesh.Name());
+                return temp;
+            }
+
+            // one material per mesh maps easily to aiMesh. Multiple material
+            // meshes need to be split.
+            const MatIndexArray& mindices = mesh.GetMaterialIndices();
+            if (doc.Settings().readMaterials && !mindices.empty()) {
+                const MatIndexArray::value_type base = mindices[0];
+                for (MatIndexArray::value_type index : mindices) {
+                    if (index != base) {
+                        return ConvertMeshMultiMaterial(mesh, model, node_global_transform, nd);
+                    }
+                }
+            }
+
+            // faster code-path, just copy the data
+            temp.push_back(ConvertMeshSingleMaterial(mesh, model, node_global_transform, nd));
+            return temp;
+        }
+
+        std::vector<unsigned int> FBXConverter::ConvertLine(const LineGeometry& line, const Model& model,
+            const aiMatrix4x4& node_global_transform, aiNode& nd)
+        {
+            std::vector<unsigned int> temp;
+
+            const std::vector<aiVector3D>& vertices = line.GetVertices();
+            const std::vector<int>& indices = line.GetIndices();
+            if (vertices.empty() || indices.empty()) {
+                FBXImporter::LogWarn("ignoring empty line: " + line.Name());
+                return temp;
+            }
+
+            aiMesh* const out_mesh = SetupEmptyMesh(line, nd);
+            out_mesh->mPrimitiveTypes |= aiPrimitiveType_LINE;
+
+            // copy vertices
+            out_mesh->mNumVertices = static_cast<unsigned int>(vertices.size());
+            out_mesh->mVertices = new aiVector3D[out_mesh->mNumVertices];
+            std::copy(vertices.begin(), vertices.end(), out_mesh->mVertices);
+
+            //Number of line segments (faces) is "Number of Points - Number of Endpoints"
+            //N.B.: Endpoints in FbxLine are denoted by negative indices.
+            //If such an Index is encountered, add 1 and multiply by -1 to get the real index.
+            unsigned int epcount = 0;
+            for (unsigned i = 0; i < indices.size(); i++)
+            {
+                if (indices[i] < 0) {
+                    epcount++;
+                }
+            }
+            unsigned int pcount = static_cast<unsigned int>( indices.size() );
+            unsigned int scount = out_mesh->mNumFaces = pcount - epcount;
+
+            aiFace* fac = out_mesh->mFaces = new aiFace[scount]();
+            for (unsigned int i = 0; i < pcount; ++i) {
+                if (indices[i] < 0) continue;
+                aiFace& f = *fac++;
+                f.mNumIndices = 2; //2 == aiPrimitiveType_LINE 
+                f.mIndices = new unsigned int[2];
+                f.mIndices[0] = indices[i];
+                int segid = indices[(i + 1 == pcount ? 0 : i + 1)];   //If we have reached he last point, wrap around
+                f.mIndices[1] = (segid < 0 ? (segid + 1)*-1 : segid); //Convert EndPoint Index to normal Index
+            }
+            temp.push_back(static_cast<unsigned int>(meshes.size() - 1));
+            return temp;
+        }
+
+        aiMesh* FBXConverter::SetupEmptyMesh(const Geometry& mesh, aiNode& nd)
+        {
+            aiMesh* const out_mesh = new aiMesh();
+            meshes.push_back(out_mesh);
+            meshes_converted[&mesh].push_back(static_cast<unsigned int>(meshes.size() - 1));
+
+            // set name
+            std::string name = mesh.Name();
+            if (name.substr(0, 10) == "Geometry::") {
+                name = name.substr(10);
+            }
+
+            if (name.length()) {
+                out_mesh->mName.Set(name);
+            }
+            else
+            {
+                out_mesh->mName = nd.mName;
+            }
+
+            return out_mesh;
+        }
+
+        unsigned int FBXConverter::ConvertMeshSingleMaterial(const MeshGeometry& mesh, const Model& model,
+            const aiMatrix4x4& node_global_transform, aiNode& nd)
+        {
+            const MatIndexArray& mindices = mesh.GetMaterialIndices();
+            aiMesh* const out_mesh = SetupEmptyMesh(mesh, nd);
+
+            const std::vector<aiVector3D>& vertices = mesh.GetVertices();
+            const std::vector<unsigned int>& faces = mesh.GetFaceIndexCounts();
+
+            // copy vertices
+            out_mesh->mNumVertices = static_cast<unsigned int>(vertices.size());
+            out_mesh->mVertices = new aiVector3D[vertices.size()];
+
+            std::copy(vertices.begin(), vertices.end(), out_mesh->mVertices);
+
+            // generate dummy faces
+            out_mesh->mNumFaces = static_cast<unsigned int>(faces.size());
+            aiFace* fac = out_mesh->mFaces = new aiFace[faces.size()]();
+
+            unsigned int cursor = 0;
+            for (unsigned int pcount : faces) {
+                aiFace& f = *fac++;
+                f.mNumIndices = pcount;
+                f.mIndices = new unsigned int[pcount];
+                switch (pcount)
+                {
+                case 1:
+                    out_mesh->mPrimitiveTypes |= aiPrimitiveType_POINT;
+                    break;
+                case 2:
+                    out_mesh->mPrimitiveTypes |= aiPrimitiveType_LINE;
+                    break;
+                case 3:
+                    out_mesh->mPrimitiveTypes |= aiPrimitiveType_TRIANGLE;
+                    break;
+                default:
+                    out_mesh->mPrimitiveTypes |= aiPrimitiveType_POLYGON;
+                    break;
+                }
+                for (unsigned int i = 0; i < pcount; ++i) {
+                    f.mIndices[i] = cursor++;
+                }
+            }
+
+            // copy normals
+            const std::vector<aiVector3D>& normals = mesh.GetNormals();
+            if (normals.size()) {
+                ai_assert(normals.size() == vertices.size());
+
+                out_mesh->mNormals = new aiVector3D[vertices.size()];
+                std::copy(normals.begin(), normals.end(), out_mesh->mNormals);
+            }
+
+            // copy tangents - assimp requires both tangents and bitangents (binormals)
+            // to be present, or neither of them. Compute binormals from normals
+            // and tangents if needed.
+            const std::vector<aiVector3D>& tangents = mesh.GetTangents();
+            const std::vector<aiVector3D>* binormals = &mesh.GetBinormals();
+
+            if (tangents.size()) {
+                std::vector<aiVector3D> tempBinormals;
+                if (!binormals->size()) {
+                    if (normals.size()) {
+                        tempBinormals.resize(normals.size());
+                        for (unsigned int i = 0; i < tangents.size(); ++i) {
+                            tempBinormals[i] = normals[i] ^ tangents[i];
+                        }
+
+                        binormals = &tempBinormals;
+                    }
+                    else {
+                        binormals = NULL;
+                    }
+                }
+
+                if (binormals) {
+                    ai_assert(tangents.size() == vertices.size());
+                    ai_assert(binormals->size() == vertices.size());
+
+                    out_mesh->mTangents = new aiVector3D[vertices.size()];
+                    std::copy(tangents.begin(), tangents.end(), out_mesh->mTangents);
+
+                    out_mesh->mBitangents = new aiVector3D[vertices.size()];
+                    std::copy(binormals->begin(), binormals->end(), out_mesh->mBitangents);
+                }
+            }
+
+            // copy texture coords
+            for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++i) {
+                const std::vector<aiVector2D>& uvs = mesh.GetTextureCoords(i);
+                if (uvs.empty()) {
+                    break;
+                }
+
+                aiVector3D* out_uv = out_mesh->mTextureCoords[i] = new aiVector3D[vertices.size()];
+                for (const aiVector2D& v : uvs) {
+                    *out_uv++ = aiVector3D(v.x, v.y, 0.0f);
+                }
+
+                out_mesh->mNumUVComponents[i] = 2;
+            }
+
+            // copy vertex colors
+            for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_COLOR_SETS; ++i) {
+                const std::vector<aiColor4D>& colors = mesh.GetVertexColors(i);
+                if (colors.empty()) {
+                    break;
+                }
+
+                out_mesh->mColors[i] = new aiColor4D[vertices.size()];
+                std::copy(colors.begin(), colors.end(), out_mesh->mColors[i]);
+            }
+
+            if (!doc.Settings().readMaterials || mindices.empty()) {
+                FBXImporter::LogError("no material assigned to mesh, setting default material");
+                out_mesh->mMaterialIndex = GetDefaultMaterial();
+            }
+            else {
+                ConvertMaterialForMesh(out_mesh, model, mesh, mindices[0]);
+            }
+
+            if (doc.Settings().readWeights && mesh.DeformerSkin() != NULL) {
+                ConvertWeights(out_mesh, model, mesh, node_global_transform, NO_MATERIAL_SEPARATION);
+            }
+
+            std::vector<aiAnimMesh*> animMeshes;
+            for (const BlendShape* blendShape : mesh.GetBlendShapes()) {
+                for (const BlendShapeChannel* blendShapeChannel : blendShape->BlendShapeChannels()) {
+                    const std::vector<const ShapeGeometry*>& shapeGeometries = blendShapeChannel->GetShapeGeometries();
+                    for (size_t i = 0; i < shapeGeometries.size(); i++) {
+                        aiAnimMesh *animMesh = aiCreateAnimMesh(out_mesh);
+                        const ShapeGeometry* shapeGeometry = shapeGeometries.at(i);
+                        const std::vector<aiVector3D>& vertices = shapeGeometry->GetVertices();
+                        const std::vector<aiVector3D>& normals = shapeGeometry->GetNormals();
+                        const std::vector<unsigned int>& indices = shapeGeometry->GetIndices();
+                        animMesh->mName.Set(FixAnimMeshName(shapeGeometry->Name()));
+                        for (size_t j = 0; j < indices.size(); j++) {
+                            unsigned int index = indices.at(j);
+                            aiVector3D vertex = vertices.at(j);
+                            aiVector3D normal = normals.at(j);
+                            unsigned int count = 0;
+                            const unsigned int* outIndices = mesh.ToOutputVertexIndex(index, count);
+                            for (unsigned int k = 0; k < count; k++) {
+                                unsigned int index = outIndices[k];
+                                animMesh->mVertices[index] += vertex;
+                                if (animMesh->mNormals != nullptr) {
+                                    animMesh->mNormals[index] += normal;
+                                    animMesh->mNormals[index].NormalizeSafe();
+                                }
+                            }
+                        }
+                        animMesh->mWeight = shapeGeometries.size() > 1 ? blendShapeChannel->DeformPercent() / 100.0f : 1.0f;
+                        animMeshes.push_back(animMesh);
+                    }
+                }
+            }
+            const size_t numAnimMeshes = animMeshes.size();
+            if (numAnimMeshes > 0) {
+                out_mesh->mNumAnimMeshes = static_cast<unsigned int>(numAnimMeshes);
+                out_mesh->mAnimMeshes = new aiAnimMesh*[numAnimMeshes];
+                for (size_t i = 0; i < numAnimMeshes; i++) {
+                    out_mesh->mAnimMeshes[i] = animMeshes.at(i);
+                }
+            }
+            return static_cast<unsigned int>(meshes.size() - 1);
+        }
+
+        std::vector<unsigned int> FBXConverter::ConvertMeshMultiMaterial(const MeshGeometry& mesh, const Model& model,
+            const aiMatrix4x4& node_global_transform, aiNode& nd)
+        {
+            const MatIndexArray& mindices = mesh.GetMaterialIndices();
+            ai_assert(mindices.size());
+
+            std::set<MatIndexArray::value_type> had;
+            std::vector<unsigned int> indices;
+
+            for (MatIndexArray::value_type index : mindices) {
+                if (had.find(index) == had.end()) {
+
+                    indices.push_back(ConvertMeshMultiMaterial(mesh, model, index, node_global_transform, nd));
+                    had.insert(index);
+                }
+            }
+
+            return indices;
+        }
+
+        unsigned int FBXConverter::ConvertMeshMultiMaterial(const MeshGeometry& mesh, const Model& model,
+            MatIndexArray::value_type index,
+            const aiMatrix4x4& node_global_transform,
+            aiNode& nd)
+        {
+            aiMesh* const out_mesh = SetupEmptyMesh(mesh, nd);
+
+            const MatIndexArray& mindices = mesh.GetMaterialIndices();
+            const std::vector<aiVector3D>& vertices = mesh.GetVertices();
+            const std::vector<unsigned int>& faces = mesh.GetFaceIndexCounts();
+
+            const bool process_weights = doc.Settings().readWeights && mesh.DeformerSkin() != NULL;
+
+            unsigned int count_faces = 0;
+            unsigned int count_vertices = 0;
+
+            // count faces
+            std::vector<unsigned int>::const_iterator itf = faces.begin();
+            for (MatIndexArray::const_iterator it = mindices.begin(),
+                end = mindices.end(); it != end; ++it, ++itf)
+            {
+                if ((*it) != index) {
+                    continue;
+                }
+                ++count_faces;
+                count_vertices += *itf;
+            }
+
+            ai_assert(count_faces);
+            ai_assert(count_vertices);
+
+            // mapping from output indices to DOM indexing, needed to resolve weights or blendshapes
+            std::vector<unsigned int> reverseMapping;
+            std::map<unsigned int, unsigned int> translateIndexMap;
+            if (process_weights || mesh.GetBlendShapes().size() > 0) {
+                reverseMapping.resize(count_vertices);
+            }
+
+            // allocate output data arrays, but don't fill them yet
+            out_mesh->mNumVertices = count_vertices;
+            out_mesh->mVertices = new aiVector3D[count_vertices];
+
+            out_mesh->mNumFaces = count_faces;
+            aiFace* fac = out_mesh->mFaces = new aiFace[count_faces]();
+
+
+            // allocate normals
+            const std::vector<aiVector3D>& normals = mesh.GetNormals();
+            if (normals.size()) {
+                ai_assert(normals.size() == vertices.size());
+                out_mesh->mNormals = new aiVector3D[vertices.size()];
+            }
+
+            // allocate tangents, binormals.
+            const std::vector<aiVector3D>& tangents = mesh.GetTangents();
+            const std::vector<aiVector3D>* binormals = &mesh.GetBinormals();
+            std::vector<aiVector3D> tempBinormals;
+
+            if (tangents.size()) {
+                if (!binormals->size()) {
+                    if (normals.size()) {
+                        // XXX this computes the binormals for the entire mesh, not only
+                        // the part for which we need them.
+                        tempBinormals.resize(normals.size());
+                        for (unsigned int i = 0; i < tangents.size(); ++i) {
+                            tempBinormals[i] = normals[i] ^ tangents[i];
+                        }
+
+                        binormals = &tempBinormals;
+                    }
+                    else {
+                        binormals = NULL;
+                    }
+                }
+
+                if (binormals) {
+                    ai_assert(tangents.size() == vertices.size() && binormals->size() == vertices.size());
+
+                    out_mesh->mTangents = new aiVector3D[vertices.size()];
+                    out_mesh->mBitangents = new aiVector3D[vertices.size()];
+                }
+            }
+
+            // allocate texture coords
+            unsigned int num_uvs = 0;
+            for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++i, ++num_uvs) {
+                const std::vector<aiVector2D>& uvs = mesh.GetTextureCoords(i);
+                if (uvs.empty()) {
+                    break;
+                }
+
+                out_mesh->mTextureCoords[i] = new aiVector3D[vertices.size()];
+                out_mesh->mNumUVComponents[i] = 2;
+            }
+
+            // allocate vertex colors
+            unsigned int num_vcs = 0;
+            for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_COLOR_SETS; ++i, ++num_vcs) {
+                const std::vector<aiColor4D>& colors = mesh.GetVertexColors(i);
+                if (colors.empty()) {
+                    break;
+                }
+
+                out_mesh->mColors[i] = new aiColor4D[vertices.size()];
+            }
+
+            unsigned int cursor = 0, in_cursor = 0;
+
+            itf = faces.begin();
+            for (MatIndexArray::const_iterator it = mindices.begin(), end = mindices.end(); it != end; ++it, ++itf)
+            {
+                const unsigned int pcount = *itf;
+                if ((*it) != index) {
+                    in_cursor += pcount;
+                    continue;
+                }
+
+                aiFace& f = *fac++;
+
+                f.mNumIndices = pcount;
+                f.mIndices = new unsigned int[pcount];
+                switch (pcount)
+                {
+                case 1:
+                    out_mesh->mPrimitiveTypes |= aiPrimitiveType_POINT;
+                    break;
+                case 2:
+                    out_mesh->mPrimitiveTypes |= aiPrimitiveType_LINE;
+                    break;
+                case 3:
+                    out_mesh->mPrimitiveTypes |= aiPrimitiveType_TRIANGLE;
+                    break;
+                default:
+                    out_mesh->mPrimitiveTypes |= aiPrimitiveType_POLYGON;
+                    break;
+                }
+                for (unsigned int i = 0; i < pcount; ++i, ++cursor, ++in_cursor) {
+                    f.mIndices[i] = cursor;
+
+                    if (reverseMapping.size()) {
+                        reverseMapping[cursor] = in_cursor;
+                        translateIndexMap[in_cursor] = cursor;
+                    }
+
+                    out_mesh->mVertices[cursor] = vertices[in_cursor];
+
+                    if (out_mesh->mNormals) {
+                        out_mesh->mNormals[cursor] = normals[in_cursor];
+                    }
+
+                    if (out_mesh->mTangents) {
+                        out_mesh->mTangents[cursor] = tangents[in_cursor];
+                        out_mesh->mBitangents[cursor] = (*binormals)[in_cursor];
+                    }
+
+                    for (unsigned int j = 0; j < num_uvs; ++j) {
+                        const std::vector<aiVector2D>& uvs = mesh.GetTextureCoords(j);
+                        out_mesh->mTextureCoords[j][cursor] = aiVector3D(uvs[in_cursor].x, uvs[in_cursor].y, 0.0f);
+                    }
+
+                    for (unsigned int j = 0; j < num_vcs; ++j) {
+                        const std::vector<aiColor4D>& cols = mesh.GetVertexColors(j);
+                        out_mesh->mColors[j][cursor] = cols[in_cursor];
+                    }
+                }
+            }
+
+            ConvertMaterialForMesh(out_mesh, model, mesh, index);
+
+            if (process_weights) {
+                ConvertWeights(out_mesh, model, mesh, node_global_transform, index, &reverseMapping);
+            }
+
+            std::vector<aiAnimMesh*> animMeshes;
+            for (const BlendShape* blendShape : mesh.GetBlendShapes()) {
+                for (const BlendShapeChannel* blendShapeChannel : blendShape->BlendShapeChannels()) {
+                    const std::vector<const ShapeGeometry*>& shapeGeometries = blendShapeChannel->GetShapeGeometries();
+                    for (size_t i = 0; i < shapeGeometries.size(); i++) {
+                        aiAnimMesh* animMesh = aiCreateAnimMesh(out_mesh);
+                        const ShapeGeometry* shapeGeometry = shapeGeometries.at(i);
+                        const std::vector<aiVector3D>& vertices = shapeGeometry->GetVertices();
+                        const std::vector<aiVector3D>& normals = shapeGeometry->GetNormals();
+                        const std::vector<unsigned int>& indices = shapeGeometry->GetIndices();
+                        animMesh->mName.Set(FixAnimMeshName(shapeGeometry->Name()));
+                        for (size_t j = 0; j < indices.size(); j++) {
+                            unsigned int index = indices.at(j);
+                            aiVector3D vertex = vertices.at(j);
+                            aiVector3D normal = normals.at(j);
+                            unsigned int count = 0;
+                            const unsigned int* outIndices = mesh.ToOutputVertexIndex(index, count);
+                            for (unsigned int k = 0; k < count; k++) {
+                                unsigned int outIndex = outIndices[k];
+                                if (translateIndexMap.find(outIndex) == translateIndexMap.end())
+                                    continue;
+                                unsigned int index = translateIndexMap[outIndex];
+                                animMesh->mVertices[index] += vertex;
+                                if (animMesh->mNormals != nullptr) {
+                                    animMesh->mNormals[index] += normal;
+                                    animMesh->mNormals[index].NormalizeSafe();
+                                }
+                            }
+                        }
+                        animMesh->mWeight = shapeGeometries.size() > 1 ? blendShapeChannel->DeformPercent() / 100.0f : 1.0f;
+                        animMeshes.push_back(animMesh);
+                    }
+                }
+            }
+
+            const size_t numAnimMeshes = animMeshes.size();
+            if (numAnimMeshes > 0) {
+                out_mesh->mNumAnimMeshes = static_cast<unsigned int>(numAnimMeshes);
+                out_mesh->mAnimMeshes = new aiAnimMesh*[numAnimMeshes];
+                for (size_t i = 0; i < numAnimMeshes; i++) {
+                    out_mesh->mAnimMeshes[i] = animMeshes.at(i);
+                }
+            }
+
+            return static_cast<unsigned int>(meshes.size() - 1);
+        }
+
+        void FBXConverter::ConvertWeights(aiMesh* out, const Model& model, const MeshGeometry& geo,
+            const aiMatrix4x4& node_global_transform,
+            unsigned int materialIndex,
+            std::vector<unsigned int>* outputVertStartIndices)
+        {
+            ai_assert(geo.DeformerSkin());
+
+            std::vector<size_t> out_indices;
+            std::vector<size_t> index_out_indices;
+            std::vector<size_t> count_out_indices;
+
+            const Skin& sk = *geo.DeformerSkin();
+
+            std::vector<aiBone*> bones;
+            bones.reserve(sk.Clusters().size());
+
+            const bool no_mat_check = materialIndex == NO_MATERIAL_SEPARATION;
+            ai_assert(no_mat_check || outputVertStartIndices);
+
+            try {
+
+                for (const Cluster* cluster : sk.Clusters()) {
+                    ai_assert(cluster);
+
+                    const WeightIndexArray& indices = cluster->GetIndices();
+
+                    if (indices.empty() && mRemoveEmptyBones ) {
+                        continue;
+                    }
+
+                    const MatIndexArray& mats = geo.GetMaterialIndices();
+
+                    bool ok = false;
+
+                    const size_t no_index_sentinel = std::numeric_limits<size_t>::max();
+
+                    count_out_indices.clear();
+                    index_out_indices.clear();
+                    out_indices.clear();
+
+                    // now check if *any* of these weights is contained in the output mesh,
+                    // taking notes so we don't need to do it twice.
+                    for (WeightIndexArray::value_type index : indices) {
+
+                        unsigned int count = 0;
+                        const unsigned int* const out_idx = geo.ToOutputVertexIndex(index, count);
+                        // ToOutputVertexIndex only returns NULL if index is out of bounds
+                        // which should never happen
+                        ai_assert(out_idx != NULL);
+
+                        index_out_indices.push_back(no_index_sentinel);
+                        count_out_indices.push_back(0);
+
+                        for (unsigned int i = 0; i < count; ++i) {
+                            if (no_mat_check || static_cast<size_t>(mats[geo.FaceForVertexIndex(out_idx[i])]) == materialIndex) {
+
+                                if (index_out_indices.back() == no_index_sentinel) {
+                                    index_out_indices.back() = out_indices.size();
+                                }
+
+                                if (no_mat_check) {
+                                    out_indices.push_back(out_idx[i]);
+                                } else {
+                                    // this extra lookup is in O(logn), so the entire algorithm becomes O(nlogn)
+                                    const std::vector<unsigned int>::iterator it = std::lower_bound(
+                                        outputVertStartIndices->begin(),
+                                        outputVertStartIndices->end(),
+                                        out_idx[i]
+                                    );
+
+                                    out_indices.push_back(std::distance(outputVertStartIndices->begin(), it));
+                                }
+
+                                ++count_out_indices.back();
+                                ok = true;
+                            }
+                        }
+                    }
+                    
+                    // if we found at least one, generate the output bones
+                    // XXX this could be heavily simplified by collecting the bone
+                    // data in a single step.
+                    if (ok && mRemoveEmptyBones) {
+                        ConvertCluster(bones, model, *cluster, out_indices, index_out_indices,
+                            count_out_indices, node_global_transform);
+                    }
+                }
+            }
+            catch (std::exception&) {
+                std::for_each(bones.begin(), bones.end(), Util::delete_fun<aiBone>());
+                throw;
+            }
+
+            if (bones.empty()) {
+                return;
+            }
+
+            out->mBones = new aiBone*[bones.size()]();
+            out->mNumBones = static_cast<unsigned int>(bones.size());
+
+            std::swap_ranges(bones.begin(), bones.end(), out->mBones);
+        }
+
+        void FBXConverter::ConvertCluster(std::vector<aiBone*>& bones, const Model& /*model*/, const Cluster& cl,
+            std::vector<size_t>& out_indices,
+            std::vector<size_t>& index_out_indices,
+            std::vector<size_t>& count_out_indices,
+            const aiMatrix4x4& node_global_transform)
+        {
+
+            aiBone* const bone = new aiBone();
+            bones.push_back(bone);
+
+            bone->mName = FixNodeName(cl.TargetNode()->Name());
+
+            bone->mOffsetMatrix = cl.TransformLink();
+            bone->mOffsetMatrix.Inverse();
+
+            bone->mOffsetMatrix = bone->mOffsetMatrix * node_global_transform;
+
+            bone->mNumWeights = static_cast<unsigned int>(out_indices.size());
+            aiVertexWeight* cursor = bone->mWeights = new aiVertexWeight[out_indices.size()];
+
+            const size_t no_index_sentinel = std::numeric_limits<size_t>::max();
+            const WeightArray& weights = cl.GetWeights();
+
+            const size_t c = index_out_indices.size();
+            for (size_t i = 0; i < c; ++i) {
+                const size_t index_index = index_out_indices[i];
+
+                if (index_index == no_index_sentinel) {
+                    continue;
+                }
+
+                const size_t cc = count_out_indices[i];
+                for (size_t j = 0; j < cc; ++j) {
+                    aiVertexWeight& out_weight = *cursor++;
+
+                    out_weight.mVertexId = static_cast<unsigned int>(out_indices[index_index + j]);
+                    out_weight.mWeight = weights[i];
+                }
+            }
+        }
+
+        void FBXConverter::ConvertMaterialForMesh(aiMesh* out, const Model& model, const MeshGeometry& geo,
+            MatIndexArray::value_type materialIndex)
+        {
+            // locate source materials for this mesh
+            const std::vector<const Material*>& mats = model.GetMaterials();
+            if (static_cast<unsigned int>(materialIndex) >= mats.size() || materialIndex < 0) {
+                FBXImporter::LogError("material index out of bounds, setting default material");
+                out->mMaterialIndex = GetDefaultMaterial();
+                return;
+            }
+
+            const Material* const mat = mats[materialIndex];
+            MaterialMap::const_iterator it = materials_converted.find(mat);
+            if (it != materials_converted.end()) {
+                out->mMaterialIndex = (*it).second;
+                return;
+            }
+
+            out->mMaterialIndex = ConvertMaterial(*mat, &geo);
+            materials_converted[mat] = out->mMaterialIndex;
+        }
+
+        unsigned int FBXConverter::GetDefaultMaterial()
+        {
+            if (defaultMaterialIndex) {
+                return defaultMaterialIndex - 1;
+            }
+
+            aiMaterial* out_mat = new aiMaterial();
+            materials.push_back(out_mat);
+
+            const aiColor3D diffuse = aiColor3D(0.8f, 0.8f, 0.8f);
+            out_mat->AddProperty(&diffuse, 1, AI_MATKEY_COLOR_DIFFUSE);
+
+            aiString s;
+            s.Set(AI_DEFAULT_MATERIAL_NAME);
+
+            out_mat->AddProperty(&s, AI_MATKEY_NAME);
+
+            defaultMaterialIndex = static_cast<unsigned int>(materials.size());
+            return defaultMaterialIndex - 1;
+        }
+
+
+        unsigned int FBXConverter::ConvertMaterial(const Material& material, const MeshGeometry* const mesh)
+        {
+            const PropertyTable& props = material.Props();
+
+            // generate empty output material
+            aiMaterial* out_mat = new aiMaterial();
+            materials_converted[&material] = static_cast<unsigned int>(materials.size());
+
+            materials.push_back(out_mat);
+
+            aiString str;
+
+            // strip Material:: prefix
+            std::string name = material.Name();
+            if (name.substr(0, 10) == "Material::") {
+                name = name.substr(10);
+            }
+
+            // set material name if not empty - this could happen
+            // and there should be no key for it in this case.
+            if (name.length()) {
+                str.Set(name);
+                out_mat->AddProperty(&str, AI_MATKEY_NAME);
+            }
+
+            // Set the shading mode as best we can: The FBX specification only mentions Lambert and Phong, and only Phong is mentioned in Assimp's aiShadingMode enum.
+            if (material.GetShadingModel() == "phong")
+            {
+                aiShadingMode shadingMode = aiShadingMode_Phong;
+                out_mat->AddProperty<aiShadingMode>(&shadingMode, 1, AI_MATKEY_SHADING_MODEL);               
+            }
+
+            // shading stuff and colors
+            SetShadingPropertiesCommon(out_mat, props);
+            SetShadingPropertiesRaw( out_mat, props, material.Textures(), mesh );
+
+            // texture assignments
+            SetTextureProperties(out_mat, material.Textures(), mesh);
+            SetTextureProperties(out_mat, material.LayeredTextures(), mesh);
+
+            return static_cast<unsigned int>(materials.size() - 1);
+        }
+
+        unsigned int FBXConverter::ConvertVideo(const Video& video)
+        {
+            // generate empty output texture
+            aiTexture* out_tex = new aiTexture();
+            textures.push_back(out_tex);
+
+            // assuming the texture is compressed
+            out_tex->mWidth = static_cast<unsigned int>(video.ContentLength()); // total data size
+            out_tex->mHeight = 0; // fixed to 0
+
+            // steal the data from the Video to avoid an additional copy
+            out_tex->pcData = reinterpret_cast<aiTexel*>(const_cast<Video&>(video).RelinquishContent());
+
+            // try to extract a hint from the file extension
+            const std::string& filename = video.RelativeFilename().empty() ? video.FileName() : video.RelativeFilename();
+            std::string ext = BaseImporter::GetExtension(filename);
+
+            if (ext == "jpeg") {
+                ext = "jpg";
+            }
+
+            if (ext.size() <= 3) {
+                memcpy(out_tex->achFormatHint, ext.c_str(), ext.size());
+            }
+
+            out_tex->mFilename.Set(filename.c_str());
+
+            return static_cast<unsigned int>(textures.size() - 1);
+        }
+
+        aiString FBXConverter::GetTexturePath(const Texture* tex)
+        {
+            aiString path;
+            path.Set(tex->RelativeFilename());
+
+            const Video* media = tex->Media();
+            if (media != nullptr) {
+                bool textureReady = false; //tells if our texture is ready (if it was loaded or if it was found)
+                unsigned int index;
+
+                VideoMap::const_iterator it = textures_converted.find(media);
+                if (it != textures_converted.end()) {
+                    index = (*it).second;
+                    textureReady = true;
+                }
+                else {
+                    if (media->ContentLength() > 0) {
+                        index = ConvertVideo(*media);
+                        textures_converted[media] = index;
+                        textureReady = true;
+                    }
+                }
+
+                // setup texture reference string (copied from ColladaLoader::FindFilenameForEffectTexture), if the texture is ready
+                if (doc.Settings().useLegacyEmbeddedTextureNaming) {
+                    if (textureReady) {
+                        // TODO: check the possibility of using the flag "AI_CONFIG_IMPORT_FBX_EMBEDDED_TEXTURES_LEGACY_NAMING"
+                        // In FBX files textures are now stored internally by Assimp with their filename included
+                        // Now Assimp can lookup through the loaded textures after all data is processed
+                        // We need to load all textures before referencing them, as FBX file format order may reference a texture before loading it
+                        // This may occur on this case too, it has to be studied
+                        path.data[0] = '*';
+                        path.length = 1 + ASSIMP_itoa10(path.data + 1, MAXLEN - 1, index);
+                    }
+                }
+            }
+
+            return path;
+        }
+
+        void FBXConverter::TrySetTextureProperties(aiMaterial* out_mat, const TextureMap& textures,
+                const std::string& propName,
+                aiTextureType target, const MeshGeometry* const mesh) {
+            TextureMap::const_iterator it = textures.find(propName);
+            if (it == textures.end()) {
+                return;
+            }
+
+            const Texture* const tex = (*it).second;
+            if (tex != 0)
+            {
+                aiString path = GetTexturePath(tex);
+                out_mat->AddProperty(&path, _AI_MATKEY_TEXTURE_BASE, target, 0);
+
+                aiUVTransform uvTrafo;
+                // XXX handle all kinds of UV transformations
+                uvTrafo.mScaling = tex->UVScaling();
+                uvTrafo.mTranslation = tex->UVTranslation();
+                out_mat->AddProperty(&uvTrafo, 1, _AI_MATKEY_UVTRANSFORM_BASE, target, 0);
+
+                const PropertyTable& props = tex->Props();
+
+                int uvIndex = 0;
+
+                bool ok;
+                const std::string& uvSet = PropertyGet<std::string>(props, "UVSet", ok);
+                if (ok) {
+                    // "default" is the name which usually appears in the FbxFileTexture template
+                    if (uvSet != "default" && uvSet.length()) {
+                        // this is a bit awkward - we need to find a mesh that uses this
+                        // material and scan its UV channels for the given UV name because
+                        // assimp references UV channels by index, not by name.
+
+                        // XXX: the case that UV channels may appear in different orders
+                        // in meshes is unhandled. A possible solution would be to sort
+                        // the UV channels alphabetically, but this would have the side
+                        // effect that the primary (first) UV channel would sometimes
+                        // be moved, causing trouble when users read only the first
+                        // UV channel and ignore UV channel assignments altogether.
+
+                        const unsigned int matIndex = static_cast<unsigned int>(std::distance(materials.begin(),
+                            std::find(materials.begin(), materials.end(), out_mat)
+                        ));
+
+
+                        uvIndex = -1;
+                        if (!mesh)
+                        {
+                            for (const MeshMap::value_type& v : meshes_converted) {
+                                const MeshGeometry* const meshGeom = dynamic_cast<const MeshGeometry*> (v.first);
+                                if (!meshGeom) {
+                                    continue;
+                                }
+
+                                const MatIndexArray& mats = meshGeom->GetMaterialIndices();
+                                if (std::find(mats.begin(), mats.end(), matIndex) == mats.end()) {
+                                    continue;
+                                }
+
+                                int index = -1;
+                                for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++i) {
+                                    if (meshGeom->GetTextureCoords(i).empty()) {
+                                        break;
+                                    }
+                                    const std::string& name = meshGeom->GetTextureCoordChannelName(i);
+                                    if (name == uvSet) {
+                                        index = static_cast<int>(i);
+                                        break;
+                                    }
+                                }
+                                if (index == -1) {
+                                    FBXImporter::LogWarn("did not find UV channel named " + uvSet + " in a mesh using this material");
+                                    continue;
+                                }
+
+                                if (uvIndex == -1) {
+                                    uvIndex = index;
+                                }
+                                else {
+                                    FBXImporter::LogWarn("the UV channel named " + uvSet +
+                                        " appears at different positions in meshes, results will be wrong");
+                                }
+                            }
+                        }
+                        else
+                        {
+                            int index = -1;
+                            for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++i) {
+                                if (mesh->GetTextureCoords(i).empty()) {
+                                    break;
+                                }
+                                const std::string& name = mesh->GetTextureCoordChannelName(i);
+                                if (name == uvSet) {
+                                    index = static_cast<int>(i);
+                                    break;
+                                }
+                            }
+                            if (index == -1) {
+                                FBXImporter::LogWarn("did not find UV channel named " + uvSet + " in a mesh using this material");
+                            }
+
+                            if (uvIndex == -1) {
+                                uvIndex = index;
+                            }
+                        }
+
+                        if (uvIndex == -1) {
+                            FBXImporter::LogWarn("failed to resolve UV channel " + uvSet + ", using first UV channel");
+                            uvIndex = 0;
+                        }
+                    }
+                }
+
+                out_mat->AddProperty(&uvIndex, 1, _AI_MATKEY_UVWSRC_BASE, target, 0);
+            }
+        }
+
+        void FBXConverter::TrySetTextureProperties(aiMaterial* out_mat, const LayeredTextureMap& layeredTextures,
+            const std::string& propName,
+            aiTextureType target, const MeshGeometry* const mesh) {
+            LayeredTextureMap::const_iterator it = layeredTextures.find(propName);
+            if (it == layeredTextures.end()) {
+                return;
+            }
+
+            int texCount = (*it).second->textureCount();
+
+            // Set the blend mode for layered textures
+            int blendmode = (*it).second->GetBlendMode();
+            out_mat->AddProperty(&blendmode, 1, _AI_MATKEY_TEXOP_BASE, target, 0);
+
+            for (int texIndex = 0; texIndex < texCount; texIndex++) {
+
+                const Texture* const tex = (*it).second->getTexture(texIndex);
+
+                aiString path = GetTexturePath(tex);
+                out_mat->AddProperty(&path, _AI_MATKEY_TEXTURE_BASE, target, texIndex);
+
+                aiUVTransform uvTrafo;
+                // XXX handle all kinds of UV transformations
+                uvTrafo.mScaling = tex->UVScaling();
+                uvTrafo.mTranslation = tex->UVTranslation();
+                out_mat->AddProperty(&uvTrafo, 1, _AI_MATKEY_UVTRANSFORM_BASE, target, texIndex);
+
+                const PropertyTable& props = tex->Props();
+
+                int uvIndex = 0;
+
+                bool ok;
+                const std::string& uvSet = PropertyGet<std::string>(props, "UVSet", ok);
+                if (ok) {
+                    // "default" is the name which usually appears in the FbxFileTexture template
+                    if (uvSet != "default" && uvSet.length()) {
+                        // this is a bit awkward - we need to find a mesh that uses this
+                        // material and scan its UV channels for the given UV name because
+                        // assimp references UV channels by index, not by name.
+
+                        // XXX: the case that UV channels may appear in different orders
+                        // in meshes is unhandled. A possible solution would be to sort
+                        // the UV channels alphabetically, but this would have the side
+                        // effect that the primary (first) UV channel would sometimes
+                        // be moved, causing trouble when users read only the first
+                        // UV channel and ignore UV channel assignments altogether.
+
+                        const unsigned int matIndex = static_cast<unsigned int>(std::distance(materials.begin(),
+                            std::find(materials.begin(), materials.end(), out_mat)
+                        ));
+
+                        uvIndex = -1;
+                        if (!mesh)
+                        {
+                            for (const MeshMap::value_type& v : meshes_converted) {
+                                const MeshGeometry* const meshGeom = dynamic_cast<const MeshGeometry*> (v.first);
+                                if (!meshGeom) {
+                                    continue;
+                                }
+
+                                const MatIndexArray& mats = meshGeom->GetMaterialIndices();
+                                if (std::find(mats.begin(), mats.end(), matIndex) == mats.end()) {
+                                    continue;
+                                }
+
+                                int index = -1;
+                                for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++i) {
+                                    if (meshGeom->GetTextureCoords(i).empty()) {
+                                        break;
+                                    }
+                                    const std::string& name = meshGeom->GetTextureCoordChannelName(i);
+                                    if (name == uvSet) {
+                                        index = static_cast<int>(i);
+                                        break;
+                                    }
+                                }
+                                if (index == -1) {
+                                    FBXImporter::LogWarn("did not find UV channel named " + uvSet + " in a mesh using this material");
+                                    continue;
+                                }
+
+                                if (uvIndex == -1) {
+                                    uvIndex = index;
+                                }
+                                else {
+                                    FBXImporter::LogWarn("the UV channel named " + uvSet +
+                                        " appears at different positions in meshes, results will be wrong");
+                                }
+                            }
+                        }
+                        else
+                        {
+                            int index = -1;
+                            for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++i) {
+                                if (mesh->GetTextureCoords(i).empty()) {
+                                    break;
+                                }
+                                const std::string& name = mesh->GetTextureCoordChannelName(i);
+                                if (name == uvSet) {
+                                    index = static_cast<int>(i);
+                                    break;
+                                }
+                            }
+                            if (index == -1) {
+                                FBXImporter::LogWarn("did not find UV channel named " + uvSet + " in a mesh using this material");
+                            }
+
+                            if (uvIndex == -1) {
+                                uvIndex = index;
+                            }
+                        }
+
+                        if (uvIndex == -1) {
+                            FBXImporter::LogWarn("failed to resolve UV channel " + uvSet + ", using first UV channel");
+                            uvIndex = 0;
+                        }
+                    }
+                }
+
+                out_mat->AddProperty(&uvIndex, 1, _AI_MATKEY_UVWSRC_BASE, target, texIndex);
+            }
+        }
+
+        void FBXConverter::SetTextureProperties(aiMaterial* out_mat, const TextureMap& textures, const MeshGeometry* const mesh)
+        {
+            TrySetTextureProperties(out_mat, textures, "DiffuseColor", aiTextureType_DIFFUSE, mesh);
+            TrySetTextureProperties(out_mat, textures, "AmbientColor", aiTextureType_AMBIENT, mesh);
+            TrySetTextureProperties(out_mat, textures, "EmissiveColor", aiTextureType_EMISSIVE, mesh);
+            TrySetTextureProperties(out_mat, textures, "SpecularColor", aiTextureType_SPECULAR, mesh);
+            TrySetTextureProperties(out_mat, textures, "SpecularFactor", aiTextureType_SPECULAR, mesh);
+            TrySetTextureProperties(out_mat, textures, "TransparentColor", aiTextureType_OPACITY, mesh);
+            TrySetTextureProperties(out_mat, textures, "ReflectionColor", aiTextureType_REFLECTION, mesh);
+            TrySetTextureProperties(out_mat, textures, "DisplacementColor", aiTextureType_DISPLACEMENT, mesh);
+            TrySetTextureProperties(out_mat, textures, "NormalMap", aiTextureType_NORMALS, mesh);
+            TrySetTextureProperties(out_mat, textures, "Bump", aiTextureType_HEIGHT, mesh);
+            TrySetTextureProperties(out_mat, textures, "ShininessExponent", aiTextureType_SHININESS, mesh);
+			TrySetTextureProperties( out_mat, textures, "TransparencyFactor", aiTextureType_OPACITY, mesh );
+			TrySetTextureProperties( out_mat, textures, "EmissiveFactor", aiTextureType_EMISSIVE, mesh );
+            //Maya counterparts
+            TrySetTextureProperties(out_mat, textures, "Maya|DiffuseTexture", aiTextureType_DIFFUSE, mesh);
+            TrySetTextureProperties(out_mat, textures, "Maya|NormalTexture", aiTextureType_NORMALS, mesh);
+            TrySetTextureProperties(out_mat, textures, "Maya|SpecularTexture", aiTextureType_SPECULAR, mesh);
+            TrySetTextureProperties(out_mat, textures, "Maya|FalloffTexture", aiTextureType_OPACITY, mesh);
+            TrySetTextureProperties(out_mat, textures, "Maya|ReflectionMapTexture", aiTextureType_REFLECTION, mesh);
+        }
+
+        void FBXConverter::SetTextureProperties(aiMaterial* out_mat, const LayeredTextureMap& layeredTextures, const MeshGeometry* const mesh)
+        {
+            TrySetTextureProperties(out_mat, layeredTextures, "DiffuseColor", aiTextureType_DIFFUSE, mesh);
+            TrySetTextureProperties(out_mat, layeredTextures, "AmbientColor", aiTextureType_AMBIENT, mesh);
+            TrySetTextureProperties(out_mat, layeredTextures, "EmissiveColor", aiTextureType_EMISSIVE, mesh);
+            TrySetTextureProperties(out_mat, layeredTextures, "SpecularColor", aiTextureType_SPECULAR, mesh);
+            TrySetTextureProperties(out_mat, layeredTextures, "SpecularFactor", aiTextureType_SPECULAR, mesh);
+            TrySetTextureProperties(out_mat, layeredTextures, "TransparentColor", aiTextureType_OPACITY, mesh);
+            TrySetTextureProperties(out_mat, layeredTextures, "ReflectionColor", aiTextureType_REFLECTION, mesh);
+            TrySetTextureProperties(out_mat, layeredTextures, "DisplacementColor", aiTextureType_DISPLACEMENT, mesh);
+            TrySetTextureProperties(out_mat, layeredTextures, "NormalMap", aiTextureType_NORMALS, mesh);
+            TrySetTextureProperties(out_mat, layeredTextures, "Bump", aiTextureType_HEIGHT, mesh);
+            TrySetTextureProperties(out_mat, layeredTextures, "ShininessExponent", aiTextureType_SHININESS, mesh);
+			TrySetTextureProperties( out_mat, layeredTextures, "EmissiveFactor", aiTextureType_EMISSIVE, mesh );
+			TrySetTextureProperties( out_mat, layeredTextures, "TransparencyFactor", aiTextureType_OPACITY, mesh );
+        }
+
+        aiColor3D FBXConverter::GetColorPropertyFactored(const PropertyTable& props, const std::string& colorName,
+            const std::string& factorName, bool& result, bool useTemplate)
+        {
+            result = true;
+
+            bool ok;
+            aiVector3D BaseColor = PropertyGet<aiVector3D>(props, colorName, ok, useTemplate);
+            if (!ok) {
+                result = false;
+                return aiColor3D(0.0f, 0.0f, 0.0f);
+            }
+
+            // if no factor name, return the colour as is
+            if (factorName.empty()) {
+                return aiColor3D(BaseColor.x, BaseColor.y, BaseColor.z);
+            }
+
+            // otherwise it should be multiplied by the factor, if found.
+            float factor = PropertyGet<float>(props, factorName, ok, useTemplate);
+            if (ok) {
+                BaseColor *= factor;
+            }
+            return aiColor3D(BaseColor.x, BaseColor.y, BaseColor.z);
+        }
+
+        aiColor3D FBXConverter::GetColorPropertyFromMaterial(const PropertyTable& props, const std::string& baseName,
+            bool& result)
+        {
+            return GetColorPropertyFactored(props, baseName + "Color", baseName + "Factor", result, true);
+        }
+
+        aiColor3D FBXConverter::GetColorProperty(const PropertyTable& props, const std::string& colorName,
+            bool& result, bool useTemplate)
+        {
+            result = true;
+            bool ok;
+            const aiVector3D& ColorVec = PropertyGet<aiVector3D>(props, colorName, ok, useTemplate);
+            if (!ok) {
+                result = false;
+                return aiColor3D(0.0f, 0.0f, 0.0f);
+            }
+            return aiColor3D(ColorVec.x, ColorVec.y, ColorVec.z);
+        }
+
+        void FBXConverter::SetShadingPropertiesCommon(aiMaterial* out_mat, const PropertyTable& props)
+        {
+            // Set shading properties.
+            // Modern FBX Files have two separate systems for defining these,
+            // with only the more comprehensive one described in the property template.
+            // Likely the other values are a legacy system,
+            // which is still always exported by the official FBX SDK.
+            //
+            // Blender's FBX import and export mostly ignore this legacy system,
+            // and as we only support recent versions of FBX anyway, we can do the same.
+            bool ok;
+
+            const aiColor3D& Diffuse = GetColorPropertyFromMaterial(props, "Diffuse", ok);
+            if (ok) {
+                out_mat->AddProperty(&Diffuse, 1, AI_MATKEY_COLOR_DIFFUSE);
+            }
+
+            const aiColor3D& Emissive = GetColorPropertyFromMaterial(props, "Emissive", ok);
+            if (ok) {
+                out_mat->AddProperty(&Emissive, 1, AI_MATKEY_COLOR_EMISSIVE);
+            }
+
+            const aiColor3D& Ambient = GetColorPropertyFromMaterial(props, "Ambient", ok);
+            if (ok) {
+                out_mat->AddProperty(&Ambient, 1, AI_MATKEY_COLOR_AMBIENT);
+            }
+
+            // we store specular factor as SHININESS_STRENGTH, so just get the color
+            const aiColor3D& Specular = GetColorProperty(props, "SpecularColor", ok, true);
+            if (ok) {
+                out_mat->AddProperty(&Specular, 1, AI_MATKEY_COLOR_SPECULAR);
+            }
+
+            // and also try to get SHININESS_STRENGTH
+            const float SpecularFactor = PropertyGet<float>(props, "SpecularFactor", ok, true);
+            if (ok) {
+                out_mat->AddProperty(&SpecularFactor, 1, AI_MATKEY_SHININESS_STRENGTH);
+            }
+
+            // and the specular exponent
+            const float ShininessExponent = PropertyGet<float>(props, "ShininessExponent", ok);
+            if (ok) {
+                out_mat->AddProperty(&ShininessExponent, 1, AI_MATKEY_SHININESS);
+            }
+
+            // TransparentColor / TransparencyFactor... gee thanks FBX :rolleyes:
+            const aiColor3D& Transparent = GetColorPropertyFactored(props, "TransparentColor", "TransparencyFactor", ok);
+            float CalculatedOpacity = 1.0f;
+            if (ok) {
+                out_mat->AddProperty(&Transparent, 1, AI_MATKEY_COLOR_TRANSPARENT);
+                // as calculated by FBX SDK 2017:
+                CalculatedOpacity = 1.0f - ((Transparent.r + Transparent.g + Transparent.b) / 3.0f);
+            }
+
+            // try to get the transparency factor
+            const float TransparencyFactor = PropertyGet<float>(props, "TransparencyFactor", ok);
+            if (ok) {
+                out_mat->AddProperty(&TransparencyFactor, 1, AI_MATKEY_TRANSPARENCYFACTOR);
+            }
+
+            // use of TransparencyFactor is inconsistent.
+            // Maya always stores it as 1.0,
+            // so we can't use it to set AI_MATKEY_OPACITY.
+            // Blender is more sensible and stores it as the alpha value.
+            // However both the FBX SDK and Blender always write an additional
+            // legacy "Opacity" field, so we can try to use that.
+            //
+            // If we can't find it,
+            // we can fall back to the value which the FBX SDK calculates
+            // from transparency colour (RGB) and factor (F) as
+            // 1.0 - F*((R+G+B)/3).
+            //
+            // There's no consistent way to interpret this opacity value,
+            // so it's up to clients to do the correct thing.
+            const float Opacity = PropertyGet<float>(props, "Opacity", ok);
+            if (ok) {
+                out_mat->AddProperty(&Opacity, 1, AI_MATKEY_OPACITY);
+            }
+            else if (CalculatedOpacity != 1.0) {
+                out_mat->AddProperty(&CalculatedOpacity, 1, AI_MATKEY_OPACITY);
+            }
+
+            // reflection color and factor are stored separately
+            const aiColor3D& Reflection = GetColorProperty(props, "ReflectionColor", ok, true);
+            if (ok) {
+                out_mat->AddProperty(&Reflection, 1, AI_MATKEY_COLOR_REFLECTIVE);
+            }
+
+            float ReflectionFactor = PropertyGet<float>(props, "ReflectionFactor", ok, true);
+            if (ok) {
+                out_mat->AddProperty(&ReflectionFactor, 1, AI_MATKEY_REFLECTIVITY);
+            }
+
+            const float BumpFactor = PropertyGet<float>(props, "BumpFactor", ok);
+            if (ok) {
+                out_mat->AddProperty(&BumpFactor, 1, AI_MATKEY_BUMPSCALING);
+            }
+
+            const float DispFactor = PropertyGet<float>(props, "DisplacementFactor", ok);
+            if (ok) {
+                out_mat->AddProperty(&DispFactor, 1, "$mat.displacementscaling", 0, 0);
+    }
+}
+
+
+void FBXConverter::SetShadingPropertiesRaw(aiMaterial* out_mat, const PropertyTable& props, const TextureMap& textures, const MeshGeometry* const mesh)
+{
+    // Add all the unparsed properties with a "$raw." prefix
+
+    const std::string prefix = "$raw.";
+
+    for (const DirectPropertyMap::value_type& prop : props.GetUnparsedProperties()) {
+
+        std::string name = prefix + prop.first;
+
+        if (const TypedProperty<aiVector3D>* interpreted = prop.second->As<TypedProperty<aiVector3D> >())
+        {
+            out_mat->AddProperty(&interpreted->Value(), 1, name.c_str(), 0, 0);
+        }
+        else if (const TypedProperty<aiColor3D>* interpreted = prop.second->As<TypedProperty<aiColor3D> >())
+        {
+            out_mat->AddProperty(&interpreted->Value(), 1, name.c_str(), 0, 0);
+        }
+        else if (const TypedProperty<aiColor4D>* interpreted = prop.second->As<TypedProperty<aiColor4D> >())
+        {
+            out_mat->AddProperty(&interpreted->Value(), 1, name.c_str(), 0, 0);
+        }
+        else if (const TypedProperty<float>* interpreted = prop.second->As<TypedProperty<float> >())
+        {
+            out_mat->AddProperty(&interpreted->Value(), 1, name.c_str(), 0, 0);
+        }
+        else if (const TypedProperty<int>* interpreted = prop.second->As<TypedProperty<int> >())
+        {
+            out_mat->AddProperty(&interpreted->Value(), 1, name.c_str(), 0, 0);
+        }
+        else if (const TypedProperty<bool>* interpreted = prop.second->As<TypedProperty<bool> >())
+        {
+            int value = interpreted->Value() ? 1 : 0;
+            out_mat->AddProperty(&value, 1, name.c_str(), 0, 0);
+        }
+        else if (const TypedProperty<std::string>* interpreted = prop.second->As<TypedProperty<std::string> >())
+        {
+            const aiString value = aiString(interpreted->Value());
+            out_mat->AddProperty(&value, name.c_str(), 0, 0);
+        }
+    }
+
+    // Add the textures' properties
+
+    for (TextureMap::const_iterator it = textures.begin(); it != textures.end(); it++) {
+
+        std::string name = prefix + it->first;
+
+        const Texture* const tex = (*it).second;
+        if (tex != nullptr)
+        {
+            aiString path;
+            path.Set(tex->RelativeFilename());
+
+            const Video* media = tex->Media();
+            if (media != nullptr && media->ContentLength() > 0) {
+                unsigned int index;
+
+                VideoMap::const_iterator it = textures_converted.find(media);
+                if (it != textures_converted.end()) {
+                    index = (*it).second;
+                }
+                else {
+                    index = ConvertVideo(*media);
+                    textures_converted[media] = index;
+                }
+
+                // setup texture reference string (copied from ColladaLoader::FindFilenameForEffectTexture)
+                path.data[0] = '*';
+                path.length = 1 + ASSIMP_itoa10(path.data + 1, MAXLEN - 1, index);
+            }
+
+            out_mat->AddProperty(&path, (name + "|file").c_str(), aiTextureType_UNKNOWN, 0);
+
+            aiUVTransform uvTrafo;
+            // XXX handle all kinds of UV transformations
+            uvTrafo.mScaling = tex->UVScaling();
+            uvTrafo.mTranslation = tex->UVTranslation();
+            out_mat->AddProperty(&uvTrafo, 1, (name + "|uvtrafo").c_str(), aiTextureType_UNKNOWN, 0);
+ 
+            int uvIndex = 0;
+
+            bool uvFound = false;
+            const std::string& uvSet = PropertyGet<std::string>(tex->Props(), "UVSet", uvFound);
+            if (uvFound) {
+                // "default" is the name which usually appears in the FbxFileTexture template
+                if (uvSet != "default" && uvSet.length()) {
+                    // this is a bit awkward - we need to find a mesh that uses this
+                    // material and scan its UV channels for the given UV name because
+                    // assimp references UV channels by index, not by name.
+
+                    // XXX: the case that UV channels may appear in different orders
+                    // in meshes is unhandled. A possible solution would be to sort
+                    // the UV channels alphabetically, but this would have the side
+                    // effect that the primary (first) UV channel would sometimes
+                    // be moved, causing trouble when users read only the first
+                    // UV channel and ignore UV channel assignments altogether.
+
+                    std::vector<aiMaterial*>::iterator materialIt = std::find(materials.begin(), materials.end(), out_mat);
+                    const unsigned int matIndex = static_cast<unsigned int>(std::distance(materials.begin(), materialIt));
+
+                    uvIndex = -1;
+                    if (!mesh)
+                    {
+                        for (const MeshMap::value_type& v : meshes_converted) {
+                            const MeshGeometry* const meshGeom = dynamic_cast<const MeshGeometry*>(v.first);
+                            if (!meshGeom) {
+                                continue;
+                            }
+
+                            const MatIndexArray& mats = meshGeom->GetMaterialIndices();
+                            if (std::find(mats.begin(), mats.end(), matIndex) == mats.end()) {
+                                continue;
+                            }
+
+                            int index = -1;
+                            for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++i) {
+                                if (meshGeom->GetTextureCoords(i).empty()) {
+                                    break;
+                                }
+                                const std::string& name = meshGeom->GetTextureCoordChannelName(i);
+                                if (name == uvSet) {
+                                    index = static_cast<int>(i);
+                                    break;
+                                }
+                            }
+                            if (index == -1) {
+                                FBXImporter::LogWarn("did not find UV channel named " + uvSet + " in a mesh using this material");
+                                continue;
+                            }
+
+                            if (uvIndex == -1) {
+                                uvIndex = index;
+                            }
+                            else {
+                                FBXImporter::LogWarn("the UV channel named " + uvSet + " appears at different positions in meshes, results will be wrong");
+                            }
+                        }
+                    }
+                    else
+                    {
+                        int index = -1;
+                        for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++i) {
+                            if (mesh->GetTextureCoords(i).empty()) {
+                                break;
+                            }
+                            const std::string& name = mesh->GetTextureCoordChannelName(i);
+                            if (name == uvSet) {
+                                index = static_cast<int>(i);
+                                break;
+                            }
+                        }
+                        if (index == -1) {
+                            FBXImporter::LogWarn("did not find UV channel named " + uvSet + " in a mesh using this material");
+                        }
+
+                        if (uvIndex == -1) {
+                            uvIndex = index;
+                        }
+                    }
+
+                    if (uvIndex == -1) {
+                        FBXImporter::LogWarn("failed to resolve UV channel " + uvSet + ", using first UV channel");
+                        uvIndex = 0;
+                    }
+                }
+            }
+
+            out_mat->AddProperty(&uvIndex, 1, (name + "|uvwsrc").c_str(), aiTextureType_UNKNOWN, 0);
+        }
+            }
+        }
+
+
+        double FBXConverter::FrameRateToDouble(FileGlobalSettings::FrameRate fp, double customFPSVal) {
+            switch (fp) {
+            case FileGlobalSettings::FrameRate_DEFAULT:
+                return 1.0;
+
+            case FileGlobalSettings::FrameRate_120:
+                return 120.0;
+
+            case FileGlobalSettings::FrameRate_100:
+                return 100.0;
+
+            case FileGlobalSettings::FrameRate_60:
+                return 60.0;
+
+            case FileGlobalSettings::FrameRate_50:
+                return 50.0;
+
+            case FileGlobalSettings::FrameRate_48:
+                return 48.0;
+
+            case FileGlobalSettings::FrameRate_30:
+            case FileGlobalSettings::FrameRate_30_DROP:
+                return 30.0;
+
+            case FileGlobalSettings::FrameRate_NTSC_DROP_FRAME:
+            case FileGlobalSettings::FrameRate_NTSC_FULL_FRAME:
+                return 29.9700262;
+
+            case FileGlobalSettings::FrameRate_PAL:
+                return 25.0;
+
+            case FileGlobalSettings::FrameRate_CINEMA:
+                return 24.0;
+
+            case FileGlobalSettings::FrameRate_1000:
+                return 1000.0;
+
+            case FileGlobalSettings::FrameRate_CINEMA_ND:
+                return 23.976;
+
+            case FileGlobalSettings::FrameRate_CUSTOM:
+                return customFPSVal;
+
+            case FileGlobalSettings::FrameRate_MAX: // this is to silence compiler warnings
+                break;
+            }
+
+            ai_assert(false);
+
+            return -1.0f;
+        }
+
+
+        void FBXConverter::ConvertAnimations()
+        {
+            // first of all determine framerate
+            const FileGlobalSettings::FrameRate fps = doc.GlobalSettings().TimeMode();
+            const float custom = doc.GlobalSettings().CustomFrameRate();
+            anim_fps = FrameRateToDouble(fps, custom);
+
+            const std::vector<const AnimationStack*>& animations = doc.AnimationStacks();
+            for (const AnimationStack* stack : animations) {
+                ConvertAnimationStack(*stack);
+            }
+        }
+
+        std::string FBXConverter::FixNodeName(const std::string& name) {
+            // strip Model:: prefix, avoiding ambiguities (i.e. don't strip if
+            // this causes ambiguities, well possible between empty identifiers,
+            // such as "Model::" and ""). Make sure the behaviour is consistent
+            // across multiple calls to FixNodeName().
+            if (name.substr(0, 7) == "Model::") {
+                std::string temp = name.substr(7);
+                return temp;
+            }
+
+            return name;
+        }
+
+        std::string FBXConverter::FixAnimMeshName(const std::string& name) {
+            if (name.length()) {
+                size_t indexOf = name.find_first_of("::");
+                if (indexOf != std::string::npos && indexOf < name.size() - 2) {
+                    return name.substr(indexOf + 2);
+                }
+            }
+            return name.length() ? name : "AnimMesh";
+        }
+
+        void FBXConverter::ConvertAnimationStack(const AnimationStack& st)
+        {
+            const AnimationLayerList& layers = st.Layers();
+            if (layers.empty()) {
+                return;
+            }
+
+            aiAnimation* const anim = new aiAnimation();
+            animations.push_back(anim);
+
+            // strip AnimationStack:: prefix
+            std::string name = st.Name();
+            if (name.substr(0, 16) == "AnimationStack::") {
+                name = name.substr(16);
+            }
+            else if (name.substr(0, 11) == "AnimStack::") {
+                name = name.substr(11);
+            }
+
+            anim->mName.Set(name);
+
+            // need to find all nodes for which we need to generate node animations -
+            // it may happen that we need to merge multiple layers, though.
+            NodeMap node_map;
+
+            // reverse mapping from curves to layers, much faster than querying
+            // the FBX DOM for it.
+            LayerMap layer_map;
+
+            const char* prop_whitelist[] = {
+                "Lcl Scaling",
+                "Lcl Rotation",
+                "Lcl Translation",
+                "DeformPercent"
+            };
+
+            std::map<std::string, morphAnimData*> morphAnimDatas;
+
+            for (const AnimationLayer* layer : layers) {
+                ai_assert(layer);
+                const AnimationCurveNodeList& nodes = layer->Nodes(prop_whitelist, 4);
+                for (const AnimationCurveNode* node : nodes) {
+                    ai_assert(node);
+                    const Model* const model = dynamic_cast<const Model*>(node->Target());
+                    if (model) {
+                        const std::string& name = FixNodeName(model->Name());
+                        node_map[name].push_back(node);
+                        layer_map[node] = layer;
+                        continue;
+                    }
+                    const BlendShapeChannel* const bsc = dynamic_cast<const BlendShapeChannel*>(node->Target());
+                    if (bsc) {
+                        ProcessMorphAnimDatas(&morphAnimDatas, bsc, node);
+                    }
+                }
+            }
+
+            // generate node animations
+            std::vector<aiNodeAnim*> node_anims;
+
+            double min_time = 1e10;
+            double max_time = -1e10;
+
+            int64_t start_time = st.LocalStart();
+            int64_t stop_time = st.LocalStop();
+            bool has_local_startstop = start_time != 0 || stop_time != 0;
+            if (!has_local_startstop) {
+                // no time range given, so accept every keyframe and use the actual min/max time
+                // the numbers are INT64_MIN/MAX, the 20000 is for safety because GenerateNodeAnimations uses an epsilon of 10000
+                start_time = -9223372036854775807ll + 20000;
+                stop_time = 9223372036854775807ll - 20000;
+            }
+
+            try {
+                for (const NodeMap::value_type& kv : node_map) {
+                    GenerateNodeAnimations(node_anims,
+                        kv.first,
+                        kv.second,
+                        layer_map,
+                        start_time, stop_time,
+                        max_time,
+                        min_time);
+                }
+            }
+            catch (std::exception&) {
+                std::for_each(node_anims.begin(), node_anims.end(), Util::delete_fun<aiNodeAnim>());
+                throw;
+            }
+
+            if (node_anims.size() || morphAnimDatas.size()) {
+                if (node_anims.size()) {
+                    anim->mChannels = new aiNodeAnim*[node_anims.size()]();
+                    anim->mNumChannels = static_cast<unsigned int>(node_anims.size());
+                    std::swap_ranges(node_anims.begin(), node_anims.end(), anim->mChannels);
+                }
+                if (morphAnimDatas.size()) {
+                    unsigned int numMorphMeshChannels = static_cast<unsigned int>(morphAnimDatas.size());
+                    anim->mMorphMeshChannels = new aiMeshMorphAnim*[numMorphMeshChannels];
+                    anim->mNumMorphMeshChannels = numMorphMeshChannels;
+                    unsigned int i = 0;
+                    for (auto morphAnimIt : morphAnimDatas) {
+                        morphAnimData* animData = morphAnimIt.second;
+                        unsigned int numKeys = static_cast<unsigned int>(animData->size());
+                        aiMeshMorphAnim* meshMorphAnim = new aiMeshMorphAnim();
+                        meshMorphAnim->mName.Set(morphAnimIt.first);
+                        meshMorphAnim->mNumKeys = numKeys;
+                        meshMorphAnim->mKeys = new aiMeshMorphKey[numKeys];
+                        unsigned int j = 0;
+                        for (auto animIt : *animData) {
+                            morphKeyData* keyData = animIt.second;
+                            unsigned int numValuesAndWeights = static_cast<unsigned int>(keyData->values.size());
+                            meshMorphAnim->mKeys[j].mNumValuesAndWeights = numValuesAndWeights;
+                            meshMorphAnim->mKeys[j].mValues = new unsigned int[numValuesAndWeights];
+                            meshMorphAnim->mKeys[j].mWeights = new double[numValuesAndWeights];
+                            meshMorphAnim->mKeys[j].mTime = CONVERT_FBX_TIME(animIt.first) * anim_fps;
+                            for (unsigned int k = 0; k < numValuesAndWeights; k++) {
+                                meshMorphAnim->mKeys[j].mValues[k] = keyData->values.at(k);
+                                meshMorphAnim->mKeys[j].mWeights[k] = keyData->weights.at(k);
+                            }
+                            j++;
+                        }
+                        anim->mMorphMeshChannels[i++] = meshMorphAnim;
+                    }
+                }
+            }
+            else {
+                // empty animations would fail validation, so drop them
+                delete anim;
+                animations.pop_back();
+                FBXImporter::LogInfo("ignoring empty AnimationStack (using IK?): " + name);
+                return;
+            }
+
+            double start_time_fps = has_local_startstop ? (CONVERT_FBX_TIME(start_time) * anim_fps) : min_time;
+            double stop_time_fps = has_local_startstop ? (CONVERT_FBX_TIME(stop_time) * anim_fps) : max_time;
+
+            // adjust relative timing for animation
+            for (unsigned int c = 0; c < anim->mNumChannels; c++) {
+                aiNodeAnim* channel = anim->mChannels[c];
+                for (uint32_t i = 0; i < channel->mNumPositionKeys; i++) {
+                    channel->mPositionKeys[i].mTime -= start_time_fps;
+                }
+                for (uint32_t i = 0; i < channel->mNumRotationKeys; i++) {
+                    channel->mRotationKeys[i].mTime -= start_time_fps;
+                }
+                for (uint32_t i = 0; i < channel->mNumScalingKeys; i++) {
+                    channel->mScalingKeys[i].mTime -= start_time_fps;
+                }
+            }
+            for (unsigned int c = 0; c < anim->mNumMorphMeshChannels; c++) {
+                aiMeshMorphAnim* channel = anim->mMorphMeshChannels[c];
+                for (uint32_t i = 0; i < channel->mNumKeys; i++) {
+                    channel->mKeys[i].mTime -= start_time_fps;
+                }
+            }
+
+            // for some mysterious reason, mDuration is simply the maximum key -- the
+            // validator always assumes animations to start at zero.
+            anim->mDuration = stop_time_fps - start_time_fps;
+            anim->mTicksPerSecond = anim_fps;
+        }
+
+        // ------------------------------------------------------------------------------------------------
+        void FBXConverter::ProcessMorphAnimDatas(std::map<std::string, morphAnimData*>* morphAnimDatas, const BlendShapeChannel* bsc, const AnimationCurveNode* node) {
+            std::vector<const Connection*> bscConnections = doc.GetConnectionsBySourceSequenced(bsc->ID(), "Deformer");
+            for (const Connection* bscConnection : bscConnections) {
+                auto bs = dynamic_cast<const BlendShape*>(bscConnection->DestinationObject());
+                if (bs) {
+                    auto channelIt = std::find(bs->BlendShapeChannels().begin(), bs->BlendShapeChannels().end(), bsc);
+                    if (channelIt != bs->BlendShapeChannels().end()) {
+                        auto channelIndex = static_cast<unsigned int>(std::distance(bs->BlendShapeChannels().begin(), channelIt));
+                        std::vector<const Connection*> bsConnections = doc.GetConnectionsBySourceSequenced(bs->ID(), "Geometry");
+                        for (const Connection* bsConnection : bsConnections) {
+                            auto geo = dynamic_cast<const Geometry*>(bsConnection->DestinationObject());
+                            if (geo) {
+                                std::vector<const Connection*> geoConnections = doc.GetConnectionsBySourceSequenced(geo->ID(), "Model");
+                                for (const Connection* geoConnection : geoConnections) {
+                                    auto model = dynamic_cast<const Model*>(geoConnection->DestinationObject());
+                                    if (model) {
+                                        auto geoIt = std::find(model->GetGeometry().begin(), model->GetGeometry().end(), geo);
+                                        auto geoIndex = static_cast<unsigned int>(std::distance(model->GetGeometry().begin(), geoIt));
+                                        auto name = aiString(FixNodeName(model->Name() + "*"));
+                                        name.length = 1 + ASSIMP_itoa10(name.data + name.length, MAXLEN - 1, geoIndex);
+                                        morphAnimData* animData;
+                                        auto animIt = morphAnimDatas->find(name.C_Str());
+                                        if (animIt == morphAnimDatas->end()) {
+                                            animData = new morphAnimData();
+                                            morphAnimDatas->insert(std::make_pair(name.C_Str(), animData));
+                                        }
+                                        else {
+                                            animData = animIt->second;
+                                        }
+                                        for (std::pair<std::string, const AnimationCurve*> curvesIt : node->Curves()) {
+                                            if (curvesIt.first == "d|DeformPercent") {
+                                                const AnimationCurve* animationCurve = curvesIt.second;
+                                                const KeyTimeList& keys = animationCurve->GetKeys();
+                                                const KeyValueList& values = animationCurve->GetValues();
+                                                unsigned int k = 0;
+                                                for (auto key : keys) {
+                                                    morphKeyData* keyData;
+                                                    auto keyIt = animData->find(key);
+                                                    if (keyIt == animData->end()) {
+                                                        keyData = new morphKeyData();
+                                                        animData->insert(std::make_pair(key, keyData));
+                                                    }
+                                                    else {
+                                                        keyData = keyIt->second;
+                                                    }
+                                                    keyData->values.push_back(channelIndex);
+                                                    keyData->weights.push_back(values.at(k) / 100.0f);
+                                                    k++;
+                                                }
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        // ------------------------------------------------------------------------------------------------
+#ifdef ASSIMP_BUILD_DEBUG
+        // ------------------------------------------------------------------------------------------------
+        // sanity check whether the input is ok
+        static void validateAnimCurveNodes(const std::vector<const AnimationCurveNode*>& curves,
+            bool strictMode) {
+            const Object* target(NULL);
+            for (const AnimationCurveNode* node : curves) {
+                if (!target) {
+                    target = node->Target();
+                }
+                if (node->Target() != target) {
+                    FBXImporter::LogWarn("Node target is nullptr type.");
+                }
+                if (strictMode) {
+                    ai_assert(node->Target() == target);
+                }
+            }
+        }
+#endif // ASSIMP_BUILD_DEBUG
+
+        // ------------------------------------------------------------------------------------------------
+        void FBXConverter::GenerateNodeAnimations(std::vector<aiNodeAnim*>& node_anims,
+            const std::string& fixed_name,
+            const std::vector<const AnimationCurveNode*>& curves,
+            const LayerMap& layer_map,
+            int64_t start, int64_t stop,
+            double& max_time,
+            double& min_time)
+        {
+
+            NodeMap node_property_map;
+            ai_assert(curves.size());
+
+#ifdef ASSIMP_BUILD_DEBUG
+            validateAnimCurveNodes(curves, doc.Settings().strictMode);
+#endif
+            const AnimationCurveNode* curve_node = NULL;
+            for (const AnimationCurveNode* node : curves) {
+                ai_assert(node);
+
+                if (node->TargetProperty().empty()) {
+                    FBXImporter::LogWarn("target property for animation curve not set: " + node->Name());
+                    continue;
+                }
+
+                curve_node = node;
+                if (node->Curves().empty()) {
+                    FBXImporter::LogWarn("no animation curves assigned to AnimationCurveNode: " + node->Name());
+                    continue;
+                }
+
+                node_property_map[node->TargetProperty()].push_back(node);
+            }
+
+            ai_assert(curve_node);
+            ai_assert(curve_node->TargetAsModel());
+
+            const Model& target = *curve_node->TargetAsModel();
+
+            // check for all possible transformation components
+            NodeMap::const_iterator chain[TransformationComp_MAXIMUM];
+
+            bool has_any = false;
+            bool has_complex = false;
+
+            for (size_t i = 0; i < TransformationComp_MAXIMUM; ++i) {
+                const TransformationComp comp = static_cast<TransformationComp>(i);
+
+                // inverse pivots don't exist in the input, we just generate them
+                if (comp == TransformationComp_RotationPivotInverse || comp == TransformationComp_ScalingPivotInverse) {
+                    chain[i] = node_property_map.end();
+                    continue;
+                }
+
+                chain[i] = node_property_map.find(NameTransformationCompProperty(comp));
+                if (chain[i] != node_property_map.end()) {
+
+                    // check if this curves contains redundant information by looking
+                    // up the corresponding node's transformation chain.
+                    if (doc.Settings().optimizeEmptyAnimationCurves &&
+                        IsRedundantAnimationData(target, comp, (*chain[i]).second)) {
+
+                        FBXImporter::LogDebug("dropping redundant animation channel for node " + target.Name());
+                        continue;
+                    }
+
+                    has_any = true;
+
+                    if (comp != TransformationComp_Rotation && comp != TransformationComp_Scaling && comp != TransformationComp_Translation)
+                    {
+                        has_complex = true;
+                    }
+                }
+            }
+
+            if (!has_any) {
+                FBXImporter::LogWarn("ignoring node animation, did not find any transformation key frames");
+                return;
+            }
+
+            // this needs to play nicely with GenerateTransformationNodeChain() which will
+            // be invoked _later_ (animations come first). If this node has only rotation,
+            // scaling and translation _and_ there are no animated other components either,
+            // we can use a single node and also a single node animation channel.
+            if (!has_complex && !NeedsComplexTransformationChain(target)) {
+
+                aiNodeAnim* const nd = GenerateSimpleNodeAnim(fixed_name, target, chain,
+                    node_property_map.end(),
+                    layer_map,
+                    start, stop,
+                    max_time,
+                    min_time,
+                    true // input is TRS order, assimp is SRT
+                );
+
+                ai_assert(nd);
+                if (nd->mNumPositionKeys == 0 && nd->mNumRotationKeys == 0 && nd->mNumScalingKeys == 0) {
+                    delete nd;
+                }
+                else {
+                    node_anims.push_back(nd);
+                }
+                return;
+            }
+
+            // otherwise, things get gruesome and we need separate animation channels
+            // for each part of the transformation chain. Remember which channels
+            // we generated and pass this information to the node conversion
+            // code to avoid nodes that have identity transform, but non-identity
+            // animations, being dropped.
+            unsigned int flags = 0, bit = 0x1;
+            for (size_t i = 0; i < TransformationComp_MAXIMUM; ++i, bit <<= 1) {
+                const TransformationComp comp = static_cast<TransformationComp>(i);
+
+                if (chain[i] != node_property_map.end()) {
+                    flags |= bit;
+
+                    ai_assert(comp != TransformationComp_RotationPivotInverse);
+                    ai_assert(comp != TransformationComp_ScalingPivotInverse);
+
+                    const std::string& chain_name = NameTransformationChainNode(fixed_name, comp);
+
+                    aiNodeAnim* na = nullptr;
+                    switch (comp)
+                    {
+                    case TransformationComp_Rotation:
+                    case TransformationComp_PreRotation:
+                    case TransformationComp_PostRotation:
+                    case TransformationComp_GeometricRotation:
+                        na = GenerateRotationNodeAnim(chain_name,
+                            target,
+                            (*chain[i]).second,
+                            layer_map,
+                            start, stop,
+                            max_time,
+                            min_time);
+
+                        break;
+
+                    case TransformationComp_RotationOffset:
+                    case TransformationComp_RotationPivot:
+                    case TransformationComp_ScalingOffset:
+                    case TransformationComp_ScalingPivot:
+                    case TransformationComp_Translation:
+                    case TransformationComp_GeometricTranslation:
+                        na = GenerateTranslationNodeAnim(chain_name,
+                            target,
+                            (*chain[i]).second,
+                            layer_map,
+                            start, stop,
+                            max_time,
+                            min_time);
+
+                        // pivoting requires us to generate an implicit inverse channel to undo the pivot translation
+                        if (comp == TransformationComp_RotationPivot) {
+                            const std::string& invName = NameTransformationChainNode(fixed_name,
+                                TransformationComp_RotationPivotInverse);
+
+                            aiNodeAnim* const inv = GenerateTranslationNodeAnim(invName,
+                                target,
+                                (*chain[i]).second,
+                                layer_map,
+                                start, stop,
+                                max_time,
+                                min_time,
+                                true);
+
+                            ai_assert(inv);
+                            if (inv->mNumPositionKeys == 0 && inv->mNumRotationKeys == 0 && inv->mNumScalingKeys == 0) {
+                                delete inv;
+                            }
+                            else {
+                                node_anims.push_back(inv);
+                            }
+
+                            ai_assert(TransformationComp_RotationPivotInverse > i);
+                            flags |= bit << (TransformationComp_RotationPivotInverse - i);
+                        }
+                        else if (comp == TransformationComp_ScalingPivot) {
+                            const std::string& invName = NameTransformationChainNode(fixed_name,
+                                TransformationComp_ScalingPivotInverse);
+
+                            aiNodeAnim* const inv = GenerateTranslationNodeAnim(invName,
+                                target,
+                                (*chain[i]).second,
+                                layer_map,
+                                start, stop,
+                                max_time,
+                                min_time,
+                                true);
+
+                            ai_assert(inv);
+                            if (inv->mNumPositionKeys == 0 && inv->mNumRotationKeys == 0 && inv->mNumScalingKeys == 0) {
+                                delete inv;
+                            }
+                            else {
+                                node_anims.push_back(inv);
+                            }
+
+                            ai_assert(TransformationComp_RotationPivotInverse > i);
+                            flags |= bit << (TransformationComp_RotationPivotInverse - i);
+                        }
+
+                        break;
+
+                    case TransformationComp_Scaling:
+                    case TransformationComp_GeometricScaling:
+                        na = GenerateScalingNodeAnim(chain_name,
+                            target,
+                            (*chain[i]).second,
+                            layer_map,
+                            start, stop,
+                            max_time,
+                            min_time);
+
+                        break;
+
+                    default:
+                        ai_assert(false);
+                    }
+
+                    ai_assert(na);
+                    if (na->mNumPositionKeys == 0 && na->mNumRotationKeys == 0 && na->mNumScalingKeys == 0) {
+                        delete na;
+                    }
+                    else {
+                        node_anims.push_back(na);
+                    }
+                    continue;
+                }
+            }
+
+            node_anim_chain_bits[fixed_name] = flags;
+        }
+
+
+        bool FBXConverter::IsRedundantAnimationData(const Model& target,
+            TransformationComp comp,
+            const std::vector<const AnimationCurveNode*>& curves) {
+            ai_assert(curves.size());
+
+            // look for animation nodes with
+            //  * sub channels for all relevant components set
+            //  * one key/value pair per component
+            //  * combined values match up the corresponding value in the bind pose node transformation
+            // only such nodes are 'redundant' for this function.
+
+            if (curves.size() > 1) {
+                return false;
+            }
+
+            const AnimationCurveNode& nd = *curves.front();
+            const AnimationCurveMap& sub_curves = nd.Curves();
+
+            const AnimationCurveMap::const_iterator dx = sub_curves.find("d|X");
+            const AnimationCurveMap::const_iterator dy = sub_curves.find("d|Y");
+            const AnimationCurveMap::const_iterator dz = sub_curves.find("d|Z");
+
+            if (dx == sub_curves.end() || dy == sub_curves.end() || dz == sub_curves.end()) {
+                return false;
+            }
+
+            const KeyValueList& vx = (*dx).second->GetValues();
+            const KeyValueList& vy = (*dy).second->GetValues();
+            const KeyValueList& vz = (*dz).second->GetValues();
+
+            if (vx.size() != 1 || vy.size() != 1 || vz.size() != 1) {
+                return false;
+            }
+
+            const aiVector3D dyn_val = aiVector3D(vx[0], vy[0], vz[0]);
+            const aiVector3D& static_val = PropertyGet<aiVector3D>(target.Props(),
+                NameTransformationCompProperty(comp),
+                TransformationCompDefaultValue(comp)
+                );
+
+            const float epsilon = 1e-6f;
+            return (dyn_val - static_val).SquareLength() < epsilon;
+        }
+
+
+        aiNodeAnim* FBXConverter::GenerateRotationNodeAnim(const std::string& name,
+            const Model& target,
+            const std::vector<const AnimationCurveNode*>& curves,
+            const LayerMap& layer_map,
+            int64_t start, int64_t stop,
+            double& max_time,
+            double& min_time)
+        {
+            std::unique_ptr<aiNodeAnim> na(new aiNodeAnim());
+            na->mNodeName.Set(name);
+
+            ConvertRotationKeys(na.get(), curves, layer_map, start, stop, max_time, min_time, target.RotationOrder());
+
+            // dummy scaling key
+            na->mScalingKeys = new aiVectorKey[1];
+            na->mNumScalingKeys = 1;
+
+            na->mScalingKeys[0].mTime = 0.;
+            na->mScalingKeys[0].mValue = aiVector3D(1.0f, 1.0f, 1.0f);
+
+            // dummy position key
+            na->mPositionKeys = new aiVectorKey[1];
+            na->mNumPositionKeys = 1;
+
+            na->mPositionKeys[0].mTime = 0.;
+            na->mPositionKeys[0].mValue = aiVector3D();
+
+            return na.release();
+        }
+
+        aiNodeAnim* FBXConverter::GenerateScalingNodeAnim(const std::string& name,
+            const Model& /*target*/,
+            const std::vector<const AnimationCurveNode*>& curves,
+            const LayerMap& layer_map,
+            int64_t start, int64_t stop,
+            double& max_time,
+            double& min_time)
+        {
+            std::unique_ptr<aiNodeAnim> na(new aiNodeAnim());
+            na->mNodeName.Set(name);
+
+            ConvertScaleKeys(na.get(), curves, layer_map, start, stop, max_time, min_time);
+
+            // dummy rotation key
+            na->mRotationKeys = new aiQuatKey[1];
+            na->mNumRotationKeys = 1;
+
+            na->mRotationKeys[0].mTime = 0.;
+            na->mRotationKeys[0].mValue = aiQuaternion();
+
+            // dummy position key
+            na->mPositionKeys = new aiVectorKey[1];
+            na->mNumPositionKeys = 1;
+
+            na->mPositionKeys[0].mTime = 0.;
+            na->mPositionKeys[0].mValue = aiVector3D();
+
+            return na.release();
+        }
+
+        aiNodeAnim* FBXConverter::GenerateTranslationNodeAnim(const std::string& name,
+            const Model& /*target*/,
+            const std::vector<const AnimationCurveNode*>& curves,
+            const LayerMap& layer_map,
+            int64_t start, int64_t stop,
+            double& max_time,
+            double& min_time,
+            bool inverse) {
+            std::unique_ptr<aiNodeAnim> na(new aiNodeAnim());
+            na->mNodeName.Set(name);
+
+            ConvertTranslationKeys(na.get(), curves, layer_map, start, stop, max_time, min_time);
+
+            if (inverse) {
+                for (unsigned int i = 0; i < na->mNumPositionKeys; ++i) {
+                    na->mPositionKeys[i].mValue *= -1.0f;
+                }
+            }
+
+            // dummy scaling key
+            na->mScalingKeys = new aiVectorKey[1];
+            na->mNumScalingKeys = 1;
+
+            na->mScalingKeys[0].mTime = 0.;
+            na->mScalingKeys[0].mValue = aiVector3D(1.0f, 1.0f, 1.0f);
+
+            // dummy rotation key
+            na->mRotationKeys = new aiQuatKey[1];
+            na->mNumRotationKeys = 1;
+
+            na->mRotationKeys[0].mTime = 0.;
+            na->mRotationKeys[0].mValue = aiQuaternion();
+
+            return na.release();
+        }
+
+        aiNodeAnim* FBXConverter::GenerateSimpleNodeAnim(const std::string& name,
+            const Model& target,
+            NodeMap::const_iterator chain[TransformationComp_MAXIMUM],
+            NodeMap::const_iterator iter_end,
+            const LayerMap& layer_map,
+            int64_t start, int64_t stop,
+            double& max_time,
+            double& min_time,
+            bool reverse_order)
+
+        {
+            std::unique_ptr<aiNodeAnim> na(new aiNodeAnim());
+            na->mNodeName.Set(name);
+
+            const PropertyTable& props = target.Props();
+
+            // need to convert from TRS order to SRT?
+            if (reverse_order) {
+
+                aiVector3D def_scale = PropertyGet(props, "Lcl Scaling", aiVector3D(1.f, 1.f, 1.f));
+                aiVector3D def_translate = PropertyGet(props, "Lcl Translation", aiVector3D(0.f, 0.f, 0.f));
+                aiVector3D def_rot = PropertyGet(props, "Lcl Rotation", aiVector3D(0.f, 0.f, 0.f));
+
+                KeyFrameListList scaling;
+                KeyFrameListList translation;
+                KeyFrameListList rotation;
+
+                if (chain[TransformationComp_Scaling] != iter_end) {
+                    scaling = GetKeyframeList((*chain[TransformationComp_Scaling]).second, start, stop);
+                }
+
+                if (chain[TransformationComp_Translation] != iter_end) {
+                    translation = GetKeyframeList((*chain[TransformationComp_Translation]).second, start, stop);
+                }
+
+                if (chain[TransformationComp_Rotation] != iter_end) {
+                    rotation = GetKeyframeList((*chain[TransformationComp_Rotation]).second, start, stop);
+                }
+
+                KeyFrameListList joined;
+                joined.insert(joined.end(), scaling.begin(), scaling.end());
+                joined.insert(joined.end(), translation.begin(), translation.end());
+                joined.insert(joined.end(), rotation.begin(), rotation.end());
+
+                const KeyTimeList& times = GetKeyTimeList(joined);
+
+                aiQuatKey* out_quat = new aiQuatKey[times.size()];
+                aiVectorKey* out_scale = new aiVectorKey[times.size()];
+                aiVectorKey* out_translation = new aiVectorKey[times.size()];
+
+                if (times.size())
+                {
+                    ConvertTransformOrder_TRStoSRT(out_quat, out_scale, out_translation,
+                        scaling,
+                        translation,
+                        rotation,
+                        times,
+                        max_time,
+                        min_time,
+                        target.RotationOrder(),
+                        def_scale,
+                        def_translate,
+                        def_rot);
+                }
+
+                // XXX remove duplicates / redundant keys which this operation did
+                // likely produce if not all three channels were equally dense.
+
+                na->mNumScalingKeys = static_cast<unsigned int>(times.size());
+                na->mNumRotationKeys = na->mNumScalingKeys;
+                na->mNumPositionKeys = na->mNumScalingKeys;
+
+                na->mScalingKeys = out_scale;
+                na->mRotationKeys = out_quat;
+                na->mPositionKeys = out_translation;
+            }
+            else {
+
+                // if a particular transformation is not given, grab it from
+                // the corresponding node to meet the semantics of aiNodeAnim,
+                // which requires all of rotation, scaling and translation
+                // to be set.
+                if (chain[TransformationComp_Scaling] != iter_end) {
+                    ConvertScaleKeys(na.get(), (*chain[TransformationComp_Scaling]).second,
+                        layer_map,
+                        start, stop,
+                        max_time,
+                        min_time);
+                }
+                else {
+                    na->mScalingKeys = new aiVectorKey[1];
+                    na->mNumScalingKeys = 1;
+
+                    na->mScalingKeys[0].mTime = 0.;
+                    na->mScalingKeys[0].mValue = PropertyGet(props, "Lcl Scaling",
+                        aiVector3D(1.f, 1.f, 1.f));
+                }
+
+                if (chain[TransformationComp_Rotation] != iter_end) {
+                    ConvertRotationKeys(na.get(), (*chain[TransformationComp_Rotation]).second,
+                        layer_map,
+                        start, stop,
+                        max_time,
+                        min_time,
+                        target.RotationOrder());
+                }
+                else {
+                    na->mRotationKeys = new aiQuatKey[1];
+                    na->mNumRotationKeys = 1;
+
+                    na->mRotationKeys[0].mTime = 0.;
+                    na->mRotationKeys[0].mValue = EulerToQuaternion(
+                        PropertyGet(props, "Lcl Rotation", aiVector3D(0.f, 0.f, 0.f)),
+                        target.RotationOrder());
+                }
+
+                if (chain[TransformationComp_Translation] != iter_end) {
+                    ConvertTranslationKeys(na.get(), (*chain[TransformationComp_Translation]).second,
+                        layer_map,
+                        start, stop,
+                        max_time,
+                        min_time);
+                }
+                else {
+                    na->mPositionKeys = new aiVectorKey[1];
+                    na->mNumPositionKeys = 1;
+
+                    na->mPositionKeys[0].mTime = 0.;
+                    na->mPositionKeys[0].mValue = PropertyGet(props, "Lcl Translation",
+                        aiVector3D(0.f, 0.f, 0.f));
+                }
+
+            }
+            return na.release();
+        }
+
+        FBXConverter::KeyFrameListList FBXConverter::GetKeyframeList(const std::vector<const AnimationCurveNode*>& nodes, int64_t start, int64_t stop)
+        {
+            KeyFrameListList inputs;
+            inputs.reserve(nodes.size() * 3);
+
+            //give some breathing room for rounding errors
+            int64_t adj_start = start - 10000;
+            int64_t adj_stop = stop + 10000;
+
+            for (const AnimationCurveNode* node : nodes) {
+                ai_assert(node);
+
+                const AnimationCurveMap& curves = node->Curves();
+                for (const AnimationCurveMap::value_type& kv : curves) {
+
+                    unsigned int mapto;
+                    if (kv.first == "d|X") {
+                        mapto = 0;
+                    }
+                    else if (kv.first == "d|Y") {
+                        mapto = 1;
+                    }
+                    else if (kv.first == "d|Z") {
+                        mapto = 2;
+                    }
+                    else {
+                        FBXImporter::LogWarn("ignoring scale animation curve, did not recognize target component");
+                        continue;
+                    }
+
+                    const AnimationCurve* const curve = kv.second;
+                    ai_assert(curve->GetKeys().size() == curve->GetValues().size() && curve->GetKeys().size());
+
+                    //get values within the start/stop time window
+                    std::shared_ptr<KeyTimeList> Keys(new KeyTimeList());
+                    std::shared_ptr<KeyValueList> Values(new KeyValueList());
+                    const size_t count = curve->GetKeys().size();
+                    Keys->reserve(count);
+                    Values->reserve(count);
+                    for (size_t n = 0; n < count; n++)
+                    {
+                        int64_t k = curve->GetKeys().at(n);
+                        if (k >= adj_start && k <= adj_stop)
+                        {
+                            Keys->push_back(k);
+                            Values->push_back(curve->GetValues().at(n));
+                        }
+                    }
+
+                    inputs.push_back(std::make_tuple(Keys, Values, mapto));
+                }
+            }
+            return inputs; // pray for NRVO :-)
+        }
+
+
+        KeyTimeList FBXConverter::GetKeyTimeList(const KeyFrameListList& inputs) {
+            ai_assert(!inputs.empty());
+
+            // reserve some space upfront - it is likely that the key-frame lists
+            // have matching time values, so max(of all key-frame lists) should
+            // be a good estimate.
+            KeyTimeList keys;
+
+            size_t estimate = 0;
+            for (const KeyFrameList& kfl : inputs) {
+                estimate = std::max(estimate, std::get<0>(kfl)->size());
+            }
+
+            keys.reserve(estimate);
+
+            std::vector<unsigned int> next_pos;
+            next_pos.resize(inputs.size(), 0);
+
+            const size_t count = inputs.size();
+            while (true) {
+
+                int64_t min_tick = std::numeric_limits<int64_t>::max();
+                for (size_t i = 0; i < count; ++i) {
+                    const KeyFrameList& kfl = inputs[i];
+
+                    if (std::get<0>(kfl)->size() > next_pos[i] && std::get<0>(kfl)->at(next_pos[i]) < min_tick) {
+                        min_tick = std::get<0>(kfl)->at(next_pos[i]);
+                    }
+                }
+
+                if (min_tick == std::numeric_limits<int64_t>::max()) {
+                    break;
+                }
+                keys.push_back(min_tick);
+
+                for (size_t i = 0; i < count; ++i) {
+                    const KeyFrameList& kfl = inputs[i];
+
+
+                    while (std::get<0>(kfl)->size() > next_pos[i] && std::get<0>(kfl)->at(next_pos[i]) == min_tick) {
+                        ++next_pos[i];
+                    }
+                }
+            }
+
+            return keys;
+        }
+
+        void FBXConverter::InterpolateKeys(aiVectorKey* valOut, const KeyTimeList& keys, const KeyFrameListList& inputs,
+            const aiVector3D& def_value,
+            double& max_time,
+            double& min_time) {
+            ai_assert(!keys.empty());
+            ai_assert(nullptr != valOut);
+
+            std::vector<unsigned int> next_pos;
+            const size_t count(inputs.size());
+
+            next_pos.resize(inputs.size(), 0);
+
+            for (KeyTimeList::value_type time : keys) {
+                ai_real result[3] = { def_value.x, def_value.y, def_value.z };
+
+                for (size_t i = 0; i < count; ++i) {
+                    const KeyFrameList& kfl = inputs[i];
+
+                    const size_t ksize = std::get<0>(kfl)->size();
+                    if (ksize == 0) {
+                        continue;
+                    }
+                    if (ksize > next_pos[i] && std::get<0>(kfl)->at(next_pos[i]) == time) {
+                        ++next_pos[i];
+                    }
+
+                    const size_t id0 = next_pos[i] > 0 ? next_pos[i] - 1 : 0;
+                    const size_t id1 = next_pos[i] == ksize ? ksize - 1 : next_pos[i];
+
+                    // use lerp for interpolation
+                    const KeyValueList::value_type valueA = std::get<1>(kfl)->at(id0);
+                    const KeyValueList::value_type valueB = std::get<1>(kfl)->at(id1);
+
+                    const KeyTimeList::value_type timeA = std::get<0>(kfl)->at(id0);
+                    const KeyTimeList::value_type timeB = std::get<0>(kfl)->at(id1);
+
+                    const ai_real factor = timeB == timeA ? ai_real(0.) : static_cast<ai_real>((time - timeA)) / (timeB - timeA);
+                    const ai_real interpValue = static_cast<ai_real>(valueA + (valueB - valueA) * factor);
+
+                    result[std::get<2>(kfl)] = interpValue;
+                }
+
+                // magic value to convert fbx times to seconds
+                valOut->mTime = CONVERT_FBX_TIME(time) * anim_fps;
+
+                min_time = std::min(min_time, valOut->mTime);
+                max_time = std::max(max_time, valOut->mTime);
+
+                valOut->mValue.x = result[0];
+                valOut->mValue.y = result[1];
+                valOut->mValue.z = result[2];
+
+                ++valOut;
+            }
+        }
+
+        void FBXConverter::InterpolateKeys(aiQuatKey* valOut, const KeyTimeList& keys, const KeyFrameListList& inputs,
+            const aiVector3D& def_value,
+            double& maxTime,
+            double& minTime,
+            Model::RotOrder order)
+        {
+            ai_assert(!keys.empty());
+            ai_assert(nullptr != valOut);
+
+            std::unique_ptr<aiVectorKey[]> temp(new aiVectorKey[keys.size()]);
+            InterpolateKeys(temp.get(), keys, inputs, def_value, maxTime, minTime);
+
+            aiMatrix4x4 m;
+
+            aiQuaternion lastq;
+
+            for (size_t i = 0, c = keys.size(); i < c; ++i) {
+
+                valOut[i].mTime = temp[i].mTime;
+
+                GetRotationMatrix(order, temp[i].mValue, m);
+                aiQuaternion quat = aiQuaternion(aiMatrix3x3(m));
+
+                // take shortest path by checking the inner product
+                // http://www.3dkingdoms.com/weekly/weekly.php?a=36
+                if (quat.x * lastq.x + quat.y * lastq.y + quat.z * lastq.z + quat.w * lastq.w < 0)
+                {
+                    quat.x = -quat.x;
+                    quat.y = -quat.y;
+                    quat.z = -quat.z;
+                    quat.w = -quat.w;
+                }
+                lastq = quat;
+
+                valOut[i].mValue = quat;
+            }
+        }
+
+        void FBXConverter::ConvertTransformOrder_TRStoSRT(aiQuatKey* out_quat, aiVectorKey* out_scale,
+            aiVectorKey* out_translation,
+            const KeyFrameListList& scaling,
+            const KeyFrameListList& translation,
+            const KeyFrameListList& rotation,
+            const KeyTimeList& times,
+            double& maxTime,
+            double& minTime,
+            Model::RotOrder order,
+            const aiVector3D& def_scale,
+            const aiVector3D& def_translate,
+            const aiVector3D& def_rotation)
+        {
+            if (rotation.size()) {
+                InterpolateKeys(out_quat, times, rotation, def_rotation, maxTime, minTime, order);
+            }
+            else {
+                for (size_t i = 0; i < times.size(); ++i) {
+                    out_quat[i].mTime = CONVERT_FBX_TIME(times[i]) * anim_fps;
+                    out_quat[i].mValue = EulerToQuaternion(def_rotation, order);
+                }
+            }
+
+            if (scaling.size()) {
+                InterpolateKeys(out_scale, times, scaling, def_scale, maxTime, minTime);
+            }
+            else {
+                for (size_t i = 0; i < times.size(); ++i) {
+                    out_scale[i].mTime = CONVERT_FBX_TIME(times[i]) * anim_fps;
+                    out_scale[i].mValue = def_scale;
+                }
+            }
+
+            if (translation.size()) {
+                InterpolateKeys(out_translation, times, translation, def_translate, maxTime, minTime);
+            }
+            else {
+                for (size_t i = 0; i < times.size(); ++i) {
+                    out_translation[i].mTime = CONVERT_FBX_TIME(times[i]) * anim_fps;
+                    out_translation[i].mValue = def_translate;
+                }
+            }
+
+            const size_t count = times.size();
+            for (size_t i = 0; i < count; ++i) {
+                aiQuaternion& r = out_quat[i].mValue;
+                aiVector3D& s = out_scale[i].mValue;
+                aiVector3D& t = out_translation[i].mValue;
+
+                aiMatrix4x4 mat, temp;
+                aiMatrix4x4::Translation(t, mat);
+                mat *= aiMatrix4x4(r.GetMatrix());
+                mat *= aiMatrix4x4::Scaling(s, temp);
+
+                mat.Decompose(s, r, t);
+            }
+        }
+
+        aiQuaternion FBXConverter::EulerToQuaternion(const aiVector3D& rot, Model::RotOrder order)
+        {
+            aiMatrix4x4 m;
+            GetRotationMatrix(order, rot, m);
+
+            return aiQuaternion(aiMatrix3x3(m));
+        }
+
+        void FBXConverter::ConvertScaleKeys(aiNodeAnim* na, const std::vector<const AnimationCurveNode*>& nodes, const LayerMap& /*layers*/,
+            int64_t start, int64_t stop,
+            double& maxTime,
+            double& minTime)
+        {
+            ai_assert(nodes.size());
+
+            // XXX for now, assume scale should be blended geometrically (i.e. two
+            // layers should be multiplied with each other). There is a FBX
+            // property in the layer to specify the behaviour, though.
+
+            const KeyFrameListList& inputs = GetKeyframeList(nodes, start, stop);
+            const KeyTimeList& keys = GetKeyTimeList(inputs);
+
+            na->mNumScalingKeys = static_cast<unsigned int>(keys.size());
+            na->mScalingKeys = new aiVectorKey[keys.size()];
+            if (keys.size() > 0) {
+                InterpolateKeys(na->mScalingKeys, keys, inputs, aiVector3D(1.0f, 1.0f, 1.0f), maxTime, minTime);
+            }
+        }
+
+        void FBXConverter::ConvertTranslationKeys(aiNodeAnim* na, const std::vector<const AnimationCurveNode*>& nodes,
+            const LayerMap& /*layers*/,
+            int64_t start, int64_t stop,
+            double& maxTime,
+            double& minTime)
+        {
+            ai_assert(nodes.size());
+
+            // XXX see notes in ConvertScaleKeys()
+            const KeyFrameListList& inputs = GetKeyframeList(nodes, start, stop);
+            const KeyTimeList& keys = GetKeyTimeList(inputs);
+
+            na->mNumPositionKeys = static_cast<unsigned int>(keys.size());
+            na->mPositionKeys = new aiVectorKey[keys.size()];
+            if (keys.size() > 0)
+                InterpolateKeys(na->mPositionKeys, keys, inputs, aiVector3D(0.0f, 0.0f, 0.0f), maxTime, minTime);
+        }
+
+        void FBXConverter::ConvertRotationKeys(aiNodeAnim* na, const std::vector<const AnimationCurveNode*>& nodes,
+            const LayerMap& /*layers*/,
+            int64_t start, int64_t stop,
+            double& maxTime,
+            double& minTime,
+            Model::RotOrder order)
+        {
+            ai_assert(nodes.size());
+
+            // XXX see notes in ConvertScaleKeys()
+            const std::vector< KeyFrameList >& inputs = GetKeyframeList(nodes, start, stop);
+            const KeyTimeList& keys = GetKeyTimeList(inputs);
+
+            na->mNumRotationKeys = static_cast<unsigned int>(keys.size());
+            na->mRotationKeys = new aiQuatKey[keys.size()];
+            if (!keys.empty()) {
+                InterpolateKeys(na->mRotationKeys, keys, inputs, aiVector3D(0.0f, 0.0f, 0.0f), maxTime, minTime, order);
+            }
+        }
+
+        void FBXConverter::ConvertGlobalSettings() {
+            if (nullptr == out) {
+                return;
+            }
+
+            out->mMetaData = aiMetadata::Alloc(15);
+            out->mMetaData->Set(0, "UpAxis", doc.GlobalSettings().UpAxis());
+            out->mMetaData->Set(1, "UpAxisSign", doc.GlobalSettings().UpAxisSign());
+            out->mMetaData->Set(2, "FrontAxis", doc.GlobalSettings().FrontAxis());
+            out->mMetaData->Set(3, "FrontAxisSign", doc.GlobalSettings().FrontAxisSign());
+            out->mMetaData->Set(4, "CoordAxis", doc.GlobalSettings().CoordAxis());
+            out->mMetaData->Set(5, "CoordAxisSign", doc.GlobalSettings().CoordAxisSign());
+            out->mMetaData->Set(6, "OriginalUpAxis", doc.GlobalSettings().OriginalUpAxis());
+            out->mMetaData->Set(7, "OriginalUpAxisSign", doc.GlobalSettings().OriginalUpAxisSign());
+            out->mMetaData->Set(8, "UnitScaleFactor", (double)doc.GlobalSettings().UnitScaleFactor());
+            out->mMetaData->Set(9, "OriginalUnitScaleFactor", doc.GlobalSettings().OriginalUnitScaleFactor());
+            out->mMetaData->Set(10, "AmbientColor", doc.GlobalSettings().AmbientColor());
+            out->mMetaData->Set(11, "FrameRate", (int)doc.GlobalSettings().TimeMode());
+            out->mMetaData->Set(12, "TimeSpanStart", doc.GlobalSettings().TimeSpanStart());
+            out->mMetaData->Set(13, "TimeSpanStop", doc.GlobalSettings().TimeSpanStop());
+            out->mMetaData->Set(14, "CustomFrameRate", doc.GlobalSettings().CustomFrameRate());
+        }
+
+        void FBXConverter::ConvertToUnitScale( FbxUnit unit ) {
+            if (mCurrentUnit == unit) {
+                return;
+            }
+
+            ai_real scale = 1.0;
+            if (mCurrentUnit == FbxUnit::cm) {
+                if (unit == FbxUnit::m) {
+                    scale = (ai_real)0.01;
+                } else if (unit == FbxUnit::km) {
+                    scale = (ai_real)0.00001;
+                }
+            } else if (mCurrentUnit == FbxUnit::m) {
+                if (unit == FbxUnit::cm) {
+                    scale = (ai_real)100.0;
+                } else if (unit == FbxUnit::km) {
+                    scale = (ai_real)0.001;
+                }
+            } else if (mCurrentUnit == FbxUnit::km) {
+                if (unit == FbxUnit::cm) {
+                    scale = (ai_real)100000.0;
+                } else if (unit == FbxUnit::m) {
+                    scale = (ai_real)1000.0;
+                }
+            }
+            
+            for (auto mesh : meshes) {
+                if (nullptr == mesh) {
+                    continue;
+                }
+
+                if (mesh->HasPositions()) {
+                    for (unsigned int i = 0; i < mesh->mNumVertices; ++i) {
+                        aiVector3D &pos = mesh->mVertices[i];
+                        pos *= scale;
+                    }
+                }
+            }
+        }
+
+        void FBXConverter::TransferDataToScene()
+        {
+            ai_assert(!out->mMeshes);
+            ai_assert(!out->mNumMeshes);
+
+            // note: the trailing () ensures initialization with NULL - not
+            // many C++ users seem to know this, so pointing it out to avoid
+            // confusion why this code works.
+
+            if (meshes.size()) {
+                out->mMeshes = new aiMesh*[meshes.size()]();
+                out->mNumMeshes = static_cast<unsigned int>(meshes.size());
+
+                std::swap_ranges(meshes.begin(), meshes.end(), out->mMeshes);
+            }
+
+            if (materials.size()) {
+                out->mMaterials = new aiMaterial*[materials.size()]();
+                out->mNumMaterials = static_cast<unsigned int>(materials.size());
+
+                std::swap_ranges(materials.begin(), materials.end(), out->mMaterials);
+            }
+
+            if (animations.size()) {
+                out->mAnimations = new aiAnimation*[animations.size()]();
+                out->mNumAnimations = static_cast<unsigned int>(animations.size());
+
+                std::swap_ranges(animations.begin(), animations.end(), out->mAnimations);
+            }
+
+            if (lights.size()) {
+                out->mLights = new aiLight*[lights.size()]();
+                out->mNumLights = static_cast<unsigned int>(lights.size());
+
+                std::swap_ranges(lights.begin(), lights.end(), out->mLights);
+            }
+
+            if (cameras.size()) {
+                out->mCameras = new aiCamera*[cameras.size()]();
+                out->mNumCameras = static_cast<unsigned int>(cameras.size());
+
+                std::swap_ranges(cameras.begin(), cameras.end(), out->mCameras);
+            }
+
+            if (textures.size()) {
+                out->mTextures = new aiTexture*[textures.size()]();
+                out->mNumTextures = static_cast<unsigned int>(textures.size());
+
+                std::swap_ranges(textures.begin(), textures.end(), out->mTextures);
+            }
+        }
+
+        // ------------------------------------------------------------------------------------------------
+        void ConvertToAssimpScene(aiScene* out, const Document& doc, bool removeEmptyBones, FbxUnit unit)
+        {
+            FBXConverter converter(out, doc, removeEmptyBones, unit);
+        }
+
+    } // !FBX
+} // !Assimp
+
+#endif
diff --git a/thirdparty/assimp/code/FBX/FBXConverter.h b/thirdparty/assimp/code/FBX/FBXConverter.h
new file mode 100644
index 0000000000..17a7bc56b7
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXConverter.h
@@ -0,0 +1,482 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXDConverter.h
+ *  @brief FBX DOM to aiScene conversion
+ */
+#ifndef INCLUDED_AI_FBX_CONVERTER_H
+#define INCLUDED_AI_FBX_CONVERTER_H
+
+#include "FBXParser.h"
+#include "FBXMeshGeometry.h"
+#include "FBXDocument.h"
+#include "FBXUtil.h"
+#include "FBXProperties.h"
+#include "FBXImporter.h"
+
+#include <assimp/anim.h>
+#include <assimp/material.h>
+#include <assimp/light.h>
+#include <assimp/texture.h>
+#include <assimp/camera.h>
+#include <assimp/StringComparison.h>
+#include <unordered_map>
+#include <unordered_set>
+
+struct aiScene;
+struct aiNode;
+struct aiMaterial;
+
+struct morphKeyData {
+    std::vector<unsigned int> values;
+    std::vector<float> weights;
+};
+typedef std::map<int64_t, morphKeyData*> morphAnimData;
+
+namespace Assimp {
+namespace FBX {
+
+class Document;
+
+enum class FbxUnit {
+    cm = 0,
+    m,
+    km,
+    NumUnits,
+
+    Undefined
+};
+
+/** 
+ *  Convert a FBX #Document to #aiScene
+ *  @param out Empty scene to be populated
+ *  @param doc Parsed FBX document
+ *  @param removeEmptyBones Will remove bones, which do not have any references to vertices.
+ */
+void ConvertToAssimpScene(aiScene* out, const Document& doc, bool removeEmptyBones, FbxUnit unit);
+
+/** Dummy class to encapsulate the conversion process */
+class FBXConverter {
+public:
+    /**
+    *  The different parts that make up the final local transformation of a fbx-node
+    */
+    enum TransformationComp {
+        TransformationComp_GeometricScalingInverse = 0,
+        TransformationComp_GeometricRotationInverse,
+        TransformationComp_GeometricTranslationInverse,
+        TransformationComp_Translation,
+        TransformationComp_RotationOffset,
+        TransformationComp_RotationPivot,
+        TransformationComp_PreRotation,
+        TransformationComp_Rotation,
+        TransformationComp_PostRotation,
+        TransformationComp_RotationPivotInverse,
+        TransformationComp_ScalingOffset,
+        TransformationComp_ScalingPivot,
+        TransformationComp_Scaling,
+        TransformationComp_ScalingPivotInverse,
+        TransformationComp_GeometricTranslation,
+        TransformationComp_GeometricRotation,
+        TransformationComp_GeometricScaling,
+
+        TransformationComp_MAXIMUM
+    };
+
+public:
+    FBXConverter(aiScene* out, const Document& doc, bool removeEmptyBones, FbxUnit unit);
+    ~FBXConverter();
+
+private:
+    // ------------------------------------------------------------------------------------------------
+    // find scene root and trigger recursive scene conversion
+    void ConvertRootNode();
+
+    // ------------------------------------------------------------------------------------------------
+    // collect and assign child nodes
+    void ConvertNodes(uint64_t id, aiNode& parent, const aiMatrix4x4& parent_transform = aiMatrix4x4());
+
+    // ------------------------------------------------------------------------------------------------
+    void ConvertLights(const Model& model, const std::string &orig_name );
+
+    // ------------------------------------------------------------------------------------------------
+    void ConvertCameras(const Model& model, const std::string &orig_name );
+
+    // ------------------------------------------------------------------------------------------------
+    void ConvertLight( const Light& light, const std::string &orig_name );
+
+    // ------------------------------------------------------------------------------------------------
+    void ConvertCamera( const Camera& cam, const std::string &orig_name );
+
+    // ------------------------------------------------------------------------------------------------
+    void GetUniqueName( const std::string &name, std::string& uniqueName );
+
+    // ------------------------------------------------------------------------------------------------
+    // this returns unified names usable within assimp identifiers (i.e. no space characters -
+    // while these would be allowed, they are a potential trouble spot so better not use them).
+    const char* NameTransformationComp(TransformationComp comp);
+
+    // ------------------------------------------------------------------------------------------------
+    // Returns an unique name for a node or traverses up a hierarchy until a non-empty name is found and
+    // then makes this name unique
+    std::string MakeUniqueNodeName(const Model* const model, const aiNode& parent);
+
+    // ------------------------------------------------------------------------------------------------
+    // note: this returns the REAL fbx property names
+    const char* NameTransformationCompProperty(TransformationComp comp);
+
+    // ------------------------------------------------------------------------------------------------
+    aiVector3D TransformationCompDefaultValue(TransformationComp comp);
+
+    // ------------------------------------------------------------------------------------------------
+    void GetRotationMatrix(Model::RotOrder mode, const aiVector3D& rotation, aiMatrix4x4& out);
+    // ------------------------------------------------------------------------------------------------
+    /**
+    *  checks if a node has more than just scaling, rotation and translation components
+    */
+    bool NeedsComplexTransformationChain(const Model& model);
+
+    // ------------------------------------------------------------------------------------------------
+    // note: name must be a FixNodeName() result
+    std::string NameTransformationChainNode(const std::string& name, TransformationComp comp);
+
+    // ------------------------------------------------------------------------------------------------
+    /**
+    *  note: memory for output_nodes will be managed by the caller
+    */
+    bool GenerateTransformationNodeChain(const Model& model, const std::string& name, std::vector<aiNode*>& output_nodes, std::vector<aiNode*>& post_output_nodes);
+
+    // ------------------------------------------------------------------------------------------------
+    void SetupNodeMetadata(const Model& model, aiNode& nd);
+
+    // ------------------------------------------------------------------------------------------------
+    void ConvertModel(const Model& model, aiNode& nd, const aiMatrix4x4& node_global_transform);
+    
+    // ------------------------------------------------------------------------------------------------
+    // MeshGeometry -> aiMesh, return mesh index + 1 or 0 if the conversion failed
+    std::vector<unsigned int> ConvertMesh(const MeshGeometry& mesh, const Model& model,
+        const aiMatrix4x4& node_global_transform, aiNode& nd);
+
+    // ------------------------------------------------------------------------------------------------
+    std::vector<unsigned int> ConvertLine(const LineGeometry& line, const Model& model,
+        const aiMatrix4x4& node_global_transform, aiNode& nd);
+
+    // ------------------------------------------------------------------------------------------------
+    aiMesh* SetupEmptyMesh(const Geometry& mesh, aiNode& nd);
+
+    // ------------------------------------------------------------------------------------------------
+    unsigned int ConvertMeshSingleMaterial(const MeshGeometry& mesh, const Model& model,
+        const aiMatrix4x4& node_global_transform, aiNode& nd);
+
+    // ------------------------------------------------------------------------------------------------
+    std::vector<unsigned int> ConvertMeshMultiMaterial(const MeshGeometry& mesh, const Model& model,
+        const aiMatrix4x4& node_global_transform, aiNode& nd);
+
+    // ------------------------------------------------------------------------------------------------
+    unsigned int ConvertMeshMultiMaterial(const MeshGeometry& mesh, const Model& model,
+        MatIndexArray::value_type index,
+        const aiMatrix4x4& node_global_transform, aiNode& nd);
+
+    // ------------------------------------------------------------------------------------------------
+    static const unsigned int NO_MATERIAL_SEPARATION = /* std::numeric_limits<unsigned int>::max() */
+        static_cast<unsigned int>(-1);
+
+    // ------------------------------------------------------------------------------------------------
+    /**
+    *  - if materialIndex == NO_MATERIAL_SEPARATION, materials are not taken into
+    *    account when determining which weights to include.
+    *  - outputVertStartIndices is only used when a material index is specified, it gives for
+    *    each output vertex the DOM index it maps to.
+    */
+    void ConvertWeights(aiMesh* out, const Model& model, const MeshGeometry& geo,
+        const aiMatrix4x4& node_global_transform = aiMatrix4x4(),
+        unsigned int materialIndex = NO_MATERIAL_SEPARATION,
+        std::vector<unsigned int>* outputVertStartIndices = NULL);
+
+    // ------------------------------------------------------------------------------------------------
+    void ConvertCluster(std::vector<aiBone*>& bones, const Model& /*model*/, const Cluster& cl,
+        std::vector<size_t>& out_indices,
+        std::vector<size_t>& index_out_indices,
+        std::vector<size_t>& count_out_indices,
+        const aiMatrix4x4& node_global_transform);
+
+    // ------------------------------------------------------------------------------------------------
+    void ConvertMaterialForMesh(aiMesh* out, const Model& model, const MeshGeometry& geo,
+        MatIndexArray::value_type materialIndex);
+
+    // ------------------------------------------------------------------------------------------------
+    unsigned int GetDefaultMaterial();
+
+    // ------------------------------------------------------------------------------------------------
+    // Material -> aiMaterial
+    unsigned int ConvertMaterial(const Material& material, const MeshGeometry* const mesh);
+
+    // ------------------------------------------------------------------------------------------------
+    // Video -> aiTexture
+    unsigned int ConvertVideo(const Video& video);
+
+    // ------------------------------------------------------------------------------------------------
+    // convert embedded texture if necessary and return actual texture path
+    aiString GetTexturePath(const Texture* tex);
+
+    // ------------------------------------------------------------------------------------------------
+    void TrySetTextureProperties(aiMaterial* out_mat, const TextureMap& textures,
+        const std::string& propName,
+        aiTextureType target, const MeshGeometry* const mesh);
+
+    // ------------------------------------------------------------------------------------------------
+    void TrySetTextureProperties(aiMaterial* out_mat, const LayeredTextureMap& layeredTextures,
+        const std::string& propName,
+        aiTextureType target, const MeshGeometry* const mesh);
+
+    // ------------------------------------------------------------------------------------------------
+    void SetTextureProperties(aiMaterial* out_mat, const TextureMap& textures, const MeshGeometry* const mesh);
+
+    // ------------------------------------------------------------------------------------------------
+    void SetTextureProperties(aiMaterial* out_mat, const LayeredTextureMap& layeredTextures, const MeshGeometry* const mesh);
+
+    // ------------------------------------------------------------------------------------------------
+    aiColor3D GetColorPropertyFromMaterial(const PropertyTable& props, const std::string& baseName,
+        bool& result);
+    aiColor3D GetColorPropertyFactored(const PropertyTable& props, const std::string& colorName,
+        const std::string& factorName, bool& result, bool useTemplate = true);
+    aiColor3D GetColorProperty(const PropertyTable& props, const std::string& colorName,
+        bool& result, bool useTemplate = true);
+
+    // ------------------------------------------------------------------------------------------------
+    void SetShadingPropertiesCommon(aiMaterial* out_mat, const PropertyTable& props);
+    void SetShadingPropertiesRaw(aiMaterial* out_mat, const PropertyTable& props, const TextureMap& textures, const MeshGeometry* const mesh);
+
+    // ------------------------------------------------------------------------------------------------
+    // get the number of fps for a FrameRate enumerated value
+    static double FrameRateToDouble(FileGlobalSettings::FrameRate fp, double customFPSVal = -1.0);
+
+    // ------------------------------------------------------------------------------------------------
+    // convert animation data to aiAnimation et al
+    void ConvertAnimations();
+
+    // ------------------------------------------------------------------------------------------------
+    // takes a fbx node name and returns the identifier to be used in the assimp output scene.
+    // the function is guaranteed to provide consistent results over multiple invocations
+    // UNLESS RenameNode() is called for a particular node name.
+    std::string FixNodeName(const std::string& name);
+    std::string FixAnimMeshName(const std::string& name);
+
+    typedef std::map<const AnimationCurveNode*, const AnimationLayer*> LayerMap;
+
+    // XXX: better use multi_map ..
+    typedef std::map<std::string, std::vector<const AnimationCurveNode*> > NodeMap;
+
+    // ------------------------------------------------------------------------------------------------
+    void ConvertAnimationStack(const AnimationStack& st);
+
+    // ------------------------------------------------------------------------------------------------
+    void ProcessMorphAnimDatas(std::map<std::string, morphAnimData*>* morphAnimDatas, const BlendShapeChannel* bsc, const AnimationCurveNode* node);
+
+    // ------------------------------------------------------------------------------------------------
+    void GenerateNodeAnimations(std::vector<aiNodeAnim*>& node_anims,
+        const std::string& fixed_name,
+        const std::vector<const AnimationCurveNode*>& curves,
+        const LayerMap& layer_map,
+        int64_t start, int64_t stop,
+        double& max_time,
+        double& min_time);
+
+    // ------------------------------------------------------------------------------------------------
+    bool IsRedundantAnimationData(const Model& target,
+        TransformationComp comp,
+        const std::vector<const AnimationCurveNode*>& curves);
+
+    // ------------------------------------------------------------------------------------------------
+    aiNodeAnim* GenerateRotationNodeAnim(const std::string& name,
+        const Model& target,
+        const std::vector<const AnimationCurveNode*>& curves,
+        const LayerMap& layer_map,
+        int64_t start, int64_t stop,
+        double& max_time,
+        double& min_time);
+
+    // ------------------------------------------------------------------------------------------------
+    aiNodeAnim* GenerateScalingNodeAnim(const std::string& name,
+        const Model& /*target*/,
+        const std::vector<const AnimationCurveNode*>& curves,
+        const LayerMap& layer_map,
+        int64_t start, int64_t stop,
+        double& max_time,
+        double& min_time);
+
+    // ------------------------------------------------------------------------------------------------
+    aiNodeAnim* GenerateTranslationNodeAnim(const std::string& name,
+        const Model& /*target*/,
+        const std::vector<const AnimationCurveNode*>& curves,
+        const LayerMap& layer_map,
+        int64_t start, int64_t stop,
+        double& max_time,
+        double& min_time,
+        bool inverse = false);
+
+    // ------------------------------------------------------------------------------------------------
+    // generate node anim, extracting only Rotation, Scaling and Translation from the given chain
+    aiNodeAnim* GenerateSimpleNodeAnim(const std::string& name,
+        const Model& target,
+        NodeMap::const_iterator chain[TransformationComp_MAXIMUM],
+        NodeMap::const_iterator iter_end,
+        const LayerMap& layer_map,
+        int64_t start, int64_t stop,
+        double& max_time,
+        double& min_time,
+        bool reverse_order = false);
+
+    // key (time), value, mapto (component index)
+    typedef std::tuple<std::shared_ptr<KeyTimeList>, std::shared_ptr<KeyValueList>, unsigned int > KeyFrameList;
+    typedef std::vector<KeyFrameList> KeyFrameListList;
+
+    // ------------------------------------------------------------------------------------------------
+    KeyFrameListList GetKeyframeList(const std::vector<const AnimationCurveNode*>& nodes, int64_t start, int64_t stop);
+
+    // ------------------------------------------------------------------------------------------------
+    KeyTimeList GetKeyTimeList(const KeyFrameListList& inputs);
+
+    // ------------------------------------------------------------------------------------------------
+    void InterpolateKeys(aiVectorKey* valOut, const KeyTimeList& keys, const KeyFrameListList& inputs,
+        const aiVector3D& def_value,
+        double& max_time,
+        double& min_time);
+
+    // ------------------------------------------------------------------------------------------------
+    void InterpolateKeys(aiQuatKey* valOut, const KeyTimeList& keys, const KeyFrameListList& inputs,
+        const aiVector3D& def_value,
+        double& maxTime,
+        double& minTime,
+        Model::RotOrder order);
+
+    // ------------------------------------------------------------------------------------------------
+    void ConvertTransformOrder_TRStoSRT(aiQuatKey* out_quat, aiVectorKey* out_scale,
+        aiVectorKey* out_translation,
+        const KeyFrameListList& scaling,
+        const KeyFrameListList& translation,
+        const KeyFrameListList& rotation,
+        const KeyTimeList& times,
+        double& maxTime,
+        double& minTime,
+        Model::RotOrder order,
+        const aiVector3D& def_scale,
+        const aiVector3D& def_translate,
+        const aiVector3D& def_rotation);
+
+    // ------------------------------------------------------------------------------------------------
+    // euler xyz -> quat
+    aiQuaternion EulerToQuaternion(const aiVector3D& rot, Model::RotOrder order);
+
+    // ------------------------------------------------------------------------------------------------
+    void ConvertScaleKeys(aiNodeAnim* na, const std::vector<const AnimationCurveNode*>& nodes, const LayerMap& /*layers*/,
+        int64_t start, int64_t stop,
+        double& maxTime,
+        double& minTime);
+
+    // ------------------------------------------------------------------------------------------------
+    void ConvertTranslationKeys(aiNodeAnim* na, const std::vector<const AnimationCurveNode*>& nodes,
+        const LayerMap& /*layers*/,
+        int64_t start, int64_t stop,
+        double& maxTime,
+        double& minTime);
+
+    // ------------------------------------------------------------------------------------------------
+    void ConvertRotationKeys(aiNodeAnim* na, const std::vector<const AnimationCurveNode*>& nodes,
+        const LayerMap& /*layers*/,
+        int64_t start, int64_t stop,
+        double& maxTime,
+        double& minTime,
+        Model::RotOrder order);
+
+    void ConvertGlobalSettings();
+
+    // ------------------------------------------------------------------------------------------------
+    //  Will perform the conversion from a given unit to the requested unit.
+    void ConvertToUnitScale(FbxUnit unit);
+
+    // ------------------------------------------------------------------------------------------------
+    // copy generated meshes, animations, lights, cameras and textures to the output scene
+    void TransferDataToScene();
+
+private:
+    // 0: not assigned yet, others: index is value - 1
+    unsigned int defaultMaterialIndex;
+
+    std::vector<aiMesh*> meshes;
+    std::vector<aiMaterial*> materials;
+    std::vector<aiAnimation*> animations;
+    std::vector<aiLight*> lights;
+    std::vector<aiCamera*> cameras;
+    std::vector<aiTexture*> textures;
+
+    using MaterialMap = std::map<const Material*, unsigned int>;
+    MaterialMap materials_converted;
+
+    using VideoMap = std::map<const Video*, unsigned int>;
+    VideoMap textures_converted;
+
+    using MeshMap = std::map<const Geometry*, std::vector<unsigned int> >;
+    MeshMap meshes_converted;
+
+    // fixed node name -> which trafo chain components have animations?
+    using NodeAnimBitMap = std::map<std::string, unsigned int> ;
+    NodeAnimBitMap node_anim_chain_bits;
+
+    // number of nodes with the same name
+    using NodeNameCache = std::unordered_map<std::string, unsigned int>;
+    NodeNameCache mNodeNames;
+
+    double anim_fps;
+
+    aiScene* const out;
+    const FBX::Document& doc;
+
+    bool mRemoveEmptyBones;
+
+    FbxUnit mCurrentUnit;
+};
+
+}
+}
+
+#endif // INCLUDED_AI_FBX_CONVERTER_H
diff --git a/thirdparty/assimp/code/FBX/FBXDeformer.cpp b/thirdparty/assimp/code/FBX/FBXDeformer.cpp
new file mode 100644
index 0000000000..6927553450
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXDeformer.cpp
@@ -0,0 +1,213 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXNoteAttribute.cpp
+ *  @brief Assimp::FBX::NodeAttribute (and subclasses) implementation
+ */
+
+#ifndef ASSIMP_BUILD_NO_FBX_IMPORTER
+
+#include "FBXParser.h"
+#include "FBXDocument.h"
+#include "FBXMeshGeometry.h"
+#include "FBXImporter.h"
+#include "FBXDocumentUtil.h"
+
+namespace Assimp {
+namespace FBX {
+
+using namespace Util;
+
+// ------------------------------------------------------------------------------------------------
+Deformer::Deformer(uint64_t id, const Element& element, const Document& doc, const std::string& name)
+    : Object(id,element,name)
+{
+    const Scope& sc = GetRequiredScope(element);
+
+    const std::string& classname = ParseTokenAsString(GetRequiredToken(element,2));
+    props = GetPropertyTable(doc,"Deformer.Fbx" + classname,element,sc,true);
+}
+
+
+// ------------------------------------------------------------------------------------------------
+Deformer::~Deformer()
+{
+
+}
+
+
+// ------------------------------------------------------------------------------------------------
+Cluster::Cluster(uint64_t id, const Element& element, const Document& doc, const std::string& name)
+: Deformer(id,element,doc,name)
+, node()
+{
+    const Scope& sc = GetRequiredScope(element);
+
+    const Element* const Indexes = sc["Indexes"];
+    const Element* const Weights = sc["Weights"];
+
+    const Element& Transform = GetRequiredElement(sc,"Transform",&element);
+    const Element& TransformLink = GetRequiredElement(sc,"TransformLink",&element);
+
+    transform = ReadMatrix(Transform);
+    transformLink = ReadMatrix(TransformLink);
+
+    // it is actually possible that there be Deformer's with no weights
+    if (!!Indexes != !!Weights) {
+        DOMError("either Indexes or Weights are missing from Cluster",&element);
+    }
+
+    if(Indexes) {
+        ParseVectorDataArray(indices,*Indexes);
+        ParseVectorDataArray(weights,*Weights);
+    }
+
+    if(indices.size() != weights.size()) {
+        DOMError("sizes of index and weight array don't match up",&element);
+    }
+
+    // read assigned node
+    const std::vector<const Connection*>& conns = doc.GetConnectionsByDestinationSequenced(ID(),"Model");
+    for(const Connection* con : conns) {
+        const Model* const mod = ProcessSimpleConnection<Model>(*con, false, "Model -> Cluster", element);
+        if(mod) {
+            node = mod;
+            break;
+        }
+    }
+
+    if (!node) {
+        DOMError("failed to read target Node for Cluster",&element);
+    }
+}
+
+
+// ------------------------------------------------------------------------------------------------
+Cluster::~Cluster()
+{
+
+}
+
+
+// ------------------------------------------------------------------------------------------------
+Skin::Skin(uint64_t id, const Element& element, const Document& doc, const std::string& name)
+: Deformer(id,element,doc,name)
+, accuracy( 0.0f ) {
+    const Scope& sc = GetRequiredScope(element);
+
+    const Element* const Link_DeformAcuracy = sc["Link_DeformAcuracy"];
+    if(Link_DeformAcuracy) {
+        accuracy = ParseTokenAsFloat(GetRequiredToken(*Link_DeformAcuracy,0));
+    }
+
+    // resolve assigned clusters
+    const std::vector<const Connection*>& conns = doc.GetConnectionsByDestinationSequenced(ID(),"Deformer");
+
+    clusters.reserve(conns.size());
+    for(const Connection* con : conns) {
+
+        const Cluster* const cluster = ProcessSimpleConnection<Cluster>(*con, false, "Cluster -> Skin", element);
+        if(cluster) {
+            clusters.push_back(cluster);
+            continue;
+        }
+    }
+}
+
+
+// ------------------------------------------------------------------------------------------------
+Skin::~Skin()
+{
+
+}
+// ------------------------------------------------------------------------------------------------
+BlendShape::BlendShape(uint64_t id, const Element& element, const Document& doc, const std::string& name)
+    : Deformer(id, element, doc, name)
+{
+    const std::vector<const Connection*>& conns = doc.GetConnectionsByDestinationSequenced(ID(), "Deformer");
+    blendShapeChannels.reserve(conns.size());
+    for (const Connection* con : conns) {
+        const BlendShapeChannel* const bspc = ProcessSimpleConnection<BlendShapeChannel>(*con, false, "BlendShapeChannel -> BlendShape", element);
+        if (bspc) {
+            blendShapeChannels.push_back(bspc);
+            continue;
+        }
+    }
+}
+// ------------------------------------------------------------------------------------------------
+BlendShape::~BlendShape()
+{
+
+}
+// ------------------------------------------------------------------------------------------------
+BlendShapeChannel::BlendShapeChannel(uint64_t id, const Element& element, const Document& doc, const std::string& name)
+    : Deformer(id, element, doc, name)
+{
+    const Scope& sc = GetRequiredScope(element);
+    const Element* const DeformPercent = sc["DeformPercent"];
+    if (DeformPercent) {
+        percent = ParseTokenAsFloat(GetRequiredToken(*DeformPercent, 0));
+    }
+    const Element* const FullWeights = sc["FullWeights"];
+    if (FullWeights) {
+        ParseVectorDataArray(fullWeights, *FullWeights);
+    }
+    const std::vector<const Connection*>& conns = doc.GetConnectionsByDestinationSequenced(ID(), "Geometry");
+    shapeGeometries.reserve(conns.size());
+    for (const Connection* con : conns) {
+        const ShapeGeometry* const sg = ProcessSimpleConnection<ShapeGeometry>(*con, false, "Shape -> BlendShapeChannel", element);
+        if (sg) {
+            shapeGeometries.push_back(sg);
+            continue;
+        }
+    }
+}
+// ------------------------------------------------------------------------------------------------
+BlendShapeChannel::~BlendShapeChannel()
+{
+
+}
+// ------------------------------------------------------------------------------------------------
+}
+}
+#endif
+
diff --git a/thirdparty/assimp/code/FBX/FBXDocument.cpp b/thirdparty/assimp/code/FBX/FBXDocument.cpp
new file mode 100644
index 0000000000..1af08fe6d8
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXDocument.cpp
@@ -0,0 +1,726 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the*
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXDocument.cpp
+ *  @brief Implementation of the FBX DOM classes
+ */
+
+#ifndef ASSIMP_BUILD_NO_FBX_IMPORTER
+
+#include "FBXDocument.h"
+#include "FBXMeshGeometry.h"
+#include "FBXParser.h"
+#include "FBXUtil.h"
+#include "FBXImporter.h"
+#include "FBXImportSettings.h"
+#include "FBXDocumentUtil.h"
+#include "FBXProperties.h"
+
+#include <memory>
+#include <functional>
+#include <map>
+
+namespace Assimp {
+namespace FBX {
+
+using namespace Util;
+
+// ------------------------------------------------------------------------------------------------
+LazyObject::LazyObject(uint64_t id, const Element& element, const Document& doc)
+: doc(doc)
+, element(element)
+, id(id)
+, flags() {
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+LazyObject::~LazyObject()
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+const Object* LazyObject::Get(bool dieOnError)
+{
+    if(IsBeingConstructed() || FailedToConstruct()) {
+        return nullptr;
+    }
+
+    if (object.get()) {
+        return object.get();
+    }
+
+    // if this is the root object, we return a dummy since there
+    // is no root object int he fbx file - it is just referenced
+    // with id 0.
+    if(id == 0L) {
+        object.reset(new Object(id, element, "Model::RootNode"));
+        return object.get();
+    }
+
+    const Token& key = element.KeyToken();
+    const TokenList& tokens = element.Tokens();
+
+    if(tokens.size() < 3) {
+        DOMError("expected at least 3 tokens: id, name and class tag",&element);
+    }
+
+    const char* err;
+    std::string name = ParseTokenAsString(*tokens[1],err);
+    if (err) {
+        DOMError(err,&element);
+    }
+
+    // small fix for binary reading: binary fbx files don't use
+    // prefixes such as Model:: in front of their names. The
+    // loading code expects this at many places, though!
+    // so convert the binary representation (a 0x0001) to the
+    // double colon notation.
+    if(tokens[1]->IsBinary()) {
+        for (size_t i = 0; i < name.length(); ++i) {
+            if (name[i] == 0x0 && name[i+1] == 0x1) {
+                name = name.substr(i+2) + "::" + name.substr(0,i);
+            }
+        }
+    }
+
+    const std::string classtag = ParseTokenAsString(*tokens[2],err);
+    if (err) {
+        DOMError(err,&element);
+    }
+
+    // prevent recursive calls
+    flags |= BEING_CONSTRUCTED;
+
+    try {
+        // this needs to be relatively fast since it happens a lot,
+        // so avoid constructing strings all the time.
+        const char* obtype = key.begin();
+        const size_t length = static_cast<size_t>(key.end()-key.begin());
+
+        // For debugging
+        //dumpObjectClassInfo( objtype, classtag );
+
+        if (!strncmp(obtype,"Geometry",length)) {
+            if (!strcmp(classtag.c_str(),"Mesh")) {
+                object.reset(new MeshGeometry(id,element,name,doc));
+            }
+            if (!strcmp(classtag.c_str(), "Shape")) {
+                object.reset(new ShapeGeometry(id, element, name, doc));
+            }
+            if (!strcmp(classtag.c_str(), "Line")) {
+                object.reset(new LineGeometry(id, element, name, doc));
+            }
+        }
+        else if (!strncmp(obtype,"NodeAttribute",length)) {
+            if (!strcmp(classtag.c_str(),"Camera")) {
+                object.reset(new Camera(id,element,doc,name));
+            }
+            else if (!strcmp(classtag.c_str(),"CameraSwitcher")) {
+                object.reset(new CameraSwitcher(id,element,doc,name));
+            }
+            else if (!strcmp(classtag.c_str(),"Light")) {
+                object.reset(new Light(id,element,doc,name));
+            }
+            else if (!strcmp(classtag.c_str(),"Null")) {
+                object.reset(new Null(id,element,doc,name));
+            }
+            else if (!strcmp(classtag.c_str(),"LimbNode")) {
+                object.reset(new LimbNode(id,element,doc,name));
+            }
+        }
+        else if (!strncmp(obtype,"Deformer",length)) {
+            if (!strcmp(classtag.c_str(),"Cluster")) {
+                object.reset(new Cluster(id,element,doc,name));
+            }
+            else if (!strcmp(classtag.c_str(),"Skin")) {
+                object.reset(new Skin(id,element,doc,name));
+            }
+            else if (!strcmp(classtag.c_str(), "BlendShape")) {
+                object.reset(new BlendShape(id, element, doc, name));
+            }
+            else if (!strcmp(classtag.c_str(), "BlendShapeChannel")) {
+                object.reset(new BlendShapeChannel(id, element, doc, name));
+            }
+        }
+        else if ( !strncmp( obtype, "Model", length ) ) {
+            // FK and IK effectors are not supported
+            if ( strcmp( classtag.c_str(), "IKEffector" ) && strcmp( classtag.c_str(), "FKEffector" ) ) {
+                object.reset( new Model( id, element, doc, name ) );
+            }
+        }
+        else if (!strncmp(obtype,"Material",length)) {
+            object.reset(new Material(id,element,doc,name));
+        }
+        else if (!strncmp(obtype,"Texture",length)) {
+            object.reset(new Texture(id,element,doc,name));
+        }
+        else if (!strncmp(obtype,"LayeredTexture",length)) {
+            object.reset(new LayeredTexture(id,element,doc,name));
+        }
+        else if (!strncmp(obtype,"Video",length)) {
+            object.reset(new Video(id,element,doc,name));
+        }
+        else if (!strncmp(obtype,"AnimationStack",length)) {
+            object.reset(new AnimationStack(id,element,name,doc));
+        }
+        else if (!strncmp(obtype,"AnimationLayer",length)) {
+            object.reset(new AnimationLayer(id,element,name,doc));
+        }
+        // note: order matters for these two
+        else if (!strncmp(obtype,"AnimationCurve",length)) {
+            object.reset(new AnimationCurve(id,element,name,doc));
+        }
+        else if (!strncmp(obtype,"AnimationCurveNode",length)) {
+            object.reset(new AnimationCurveNode(id,element,name,doc));
+        }
+    }
+    catch(std::exception& ex) {
+        flags &= ~BEING_CONSTRUCTED;
+        flags |= FAILED_TO_CONSTRUCT;
+
+        if(dieOnError || doc.Settings().strictMode) {
+            throw;
+        }
+
+        // note: the error message is already formatted, so raw logging is ok
+        if(!DefaultLogger::isNullLogger()) {
+            ASSIMP_LOG_ERROR(ex.what());
+        }
+        return NULL;
+    }
+
+    if (!object.get()) {
+        //DOMError("failed to convert element to DOM object, class: " + classtag + ", name: " + name,&element);
+    }
+
+    flags &= ~BEING_CONSTRUCTED;
+    return object.get();
+}
+
+// ------------------------------------------------------------------------------------------------
+Object::Object(uint64_t id, const Element& element, const std::string& name)
+: element(element)
+, name(name)
+, id(id)
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+Object::~Object()
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+FileGlobalSettings::FileGlobalSettings(const Document& doc, std::shared_ptr<const PropertyTable> props)
+: props(props)
+, doc(doc)
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+FileGlobalSettings::~FileGlobalSettings()
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+Document::Document(const Parser& parser, const ImportSettings& settings)
+: settings(settings)
+, parser(parser)
+{
+    // Cannot use array default initialization syntax because vc8 fails on it
+    for (auto &timeStamp : creationTimeStamp) {
+        timeStamp = 0;
+    }
+
+    ReadHeader();
+    ReadPropertyTemplates();
+
+    ReadGlobalSettings();
+
+    // This order is important, connections need parsed objects to check
+    // whether connections are ok or not. Objects may not be evaluated yet,
+    // though, since this may require valid connections.
+    ReadObjects();
+    ReadConnections();
+}
+
+// ------------------------------------------------------------------------------------------------
+Document::~Document()
+{
+    for(ObjectMap::value_type& v : objects) {
+        delete v.second;
+    }
+
+    for(ConnectionMap::value_type& v : src_connections) {
+        delete v.second;
+    }
+    // |dest_connections| contain the same Connection objects as the |src_connections|
+}
+
+// ------------------------------------------------------------------------------------------------
+static const unsigned int LowerSupportedVersion = 7100;
+static const unsigned int UpperSupportedVersion = 7400;
+
+void Document::ReadHeader() {
+    // Read ID objects from "Objects" section
+    const Scope& sc = parser.GetRootScope();
+    const Element* const ehead = sc["FBXHeaderExtension"];
+    if(!ehead || !ehead->Compound()) {
+        DOMError("no FBXHeaderExtension dictionary found");
+    }
+
+    const Scope& shead = *ehead->Compound();
+    fbxVersion = ParseTokenAsInt(GetRequiredToken(GetRequiredElement(shead,"FBXVersion",ehead),0));
+
+    // While we may have some success with newer files, we don't support
+    // the older 6.n fbx format
+    if(fbxVersion < LowerSupportedVersion ) {
+        DOMError("unsupported, old format version, supported are only FBX 2011, FBX 2012 and FBX 2013");
+    }
+    if(fbxVersion > UpperSupportedVersion ) {
+        if(Settings().strictMode) {
+            DOMError("unsupported, newer format version, supported are only FBX 2011, FBX 2012 and FBX 2013"
+                " (turn off strict mode to try anyhow) ");
+        }
+        else {
+            DOMWarning("unsupported, newer format version, supported are only FBX 2011, FBX 2012 and FBX 2013,"
+                " trying to read it nevertheless");
+        }
+    }
+
+    const Element* const ecreator = shead["Creator"];
+    if(ecreator) {
+        creator = ParseTokenAsString(GetRequiredToken(*ecreator,0));
+    }
+
+    const Element* const etimestamp = shead["CreationTimeStamp"];
+    if(etimestamp && etimestamp->Compound()) {
+        const Scope& stimestamp = *etimestamp->Compound();
+        creationTimeStamp[0] = ParseTokenAsInt(GetRequiredToken(GetRequiredElement(stimestamp,"Year"),0));
+        creationTimeStamp[1] = ParseTokenAsInt(GetRequiredToken(GetRequiredElement(stimestamp,"Month"),0));
+        creationTimeStamp[2] = ParseTokenAsInt(GetRequiredToken(GetRequiredElement(stimestamp,"Day"),0));
+        creationTimeStamp[3] = ParseTokenAsInt(GetRequiredToken(GetRequiredElement(stimestamp,"Hour"),0));
+        creationTimeStamp[4] = ParseTokenAsInt(GetRequiredToken(GetRequiredElement(stimestamp,"Minute"),0));
+        creationTimeStamp[5] = ParseTokenAsInt(GetRequiredToken(GetRequiredElement(stimestamp,"Second"),0));
+        creationTimeStamp[6] = ParseTokenAsInt(GetRequiredToken(GetRequiredElement(stimestamp,"Millisecond"),0));
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+void Document::ReadGlobalSettings()
+{
+    const Scope& sc = parser.GetRootScope();
+    const Element* const ehead = sc["GlobalSettings"];
+    if ( nullptr == ehead || !ehead->Compound() ) {
+        DOMWarning( "no GlobalSettings dictionary found" );
+        globals.reset(new FileGlobalSettings(*this, std::make_shared<const PropertyTable>()));
+        return;
+    }
+
+    std::shared_ptr<const PropertyTable> props = GetPropertyTable( *this, "", *ehead, *ehead->Compound(), true );
+
+    //double v = PropertyGet<float>( *props.get(), std::string("UnitScaleFactor"), 1.0 );
+
+    if(!props) {
+        DOMError("GlobalSettings dictionary contains no property table");
+    }
+
+    globals.reset(new FileGlobalSettings(*this, props));
+}
+
+// ------------------------------------------------------------------------------------------------
+void Document::ReadObjects()
+{
+    // read ID objects from "Objects" section
+    const Scope& sc = parser.GetRootScope();
+    const Element* const eobjects = sc["Objects"];
+    if(!eobjects || !eobjects->Compound()) {
+        DOMError("no Objects dictionary found");
+    }
+
+    // add a dummy entry to represent the Model::RootNode object (id 0),
+    // which is only indirectly defined in the input file
+    objects[0] = new LazyObject(0L, *eobjects, *this);
+
+    const Scope& sobjects = *eobjects->Compound();
+    for(const ElementMap::value_type& el : sobjects.Elements()) {
+
+        // extract ID
+        const TokenList& tok = el.second->Tokens();
+
+        if (tok.empty()) {
+            DOMError("expected ID after object key",el.second);
+        }
+
+        const char* err;
+        const uint64_t id = ParseTokenAsID(*tok[0], err);
+        if(err) {
+            DOMError(err,el.second);
+        }
+
+        // id=0 is normally implicit
+        if(id == 0L) {
+            DOMError("encountered object with implicitly defined id 0",el.second);
+        }
+
+        if(objects.find(id) != objects.end()) {
+            DOMWarning("encountered duplicate object id, ignoring first occurrence",el.second);
+        }
+
+        objects[id] = new LazyObject(id, *el.second, *this);
+
+        // grab all animation stacks upfront since there is no listing of them
+        if(!strcmp(el.first.c_str(),"AnimationStack")) {
+            animationStacks.push_back(id);
+        }
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+void Document::ReadPropertyTemplates()
+{
+    const Scope& sc = parser.GetRootScope();
+    // read property templates from "Definitions" section
+    const Element* const edefs = sc["Definitions"];
+    if(!edefs || !edefs->Compound()) {
+        DOMWarning("no Definitions dictionary found");
+        return;
+    }
+
+    const Scope& sdefs = *edefs->Compound();
+    const ElementCollection otypes = sdefs.GetCollection("ObjectType");
+    for(ElementMap::const_iterator it = otypes.first; it != otypes.second; ++it) {
+        const Element& el = *(*it).second;
+        const Scope* sc = el.Compound();
+        if(!sc) {
+            DOMWarning("expected nested scope in ObjectType, ignoring",&el);
+            continue;
+        }
+
+        const TokenList& tok = el.Tokens();
+        if(tok.empty()) {
+            DOMWarning("expected name for ObjectType element, ignoring",&el);
+            continue;
+        }
+
+        const std::string& oname = ParseTokenAsString(*tok[0]);
+
+        const ElementCollection templs = sc->GetCollection("PropertyTemplate");
+        for(ElementMap::const_iterator it = templs.first; it != templs.second; ++it) {
+            const Element& el = *(*it).second;
+            const Scope* sc = el.Compound();
+            if(!sc) {
+                DOMWarning("expected nested scope in PropertyTemplate, ignoring",&el);
+                continue;
+            }
+
+            const TokenList& tok = el.Tokens();
+            if(tok.empty()) {
+                DOMWarning("expected name for PropertyTemplate element, ignoring",&el);
+                continue;
+            }
+
+            const std::string& pname = ParseTokenAsString(*tok[0]);
+
+            const Element* Properties70 = (*sc)["Properties70"];
+            if(Properties70) {
+                std::shared_ptr<const PropertyTable> props = std::make_shared<const PropertyTable>(
+                    *Properties70,std::shared_ptr<const PropertyTable>(static_cast<const PropertyTable*>(NULL))
+                );
+
+                templates[oname+"."+pname] = props;
+            }
+        }
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+void Document::ReadConnections()
+{
+    const Scope& sc = parser.GetRootScope();
+    // read property templates from "Definitions" section
+    const Element* const econns = sc["Connections"];
+    if(!econns || !econns->Compound()) {
+        DOMError("no Connections dictionary found");
+    }
+
+    uint64_t insertionOrder = 0l;
+    const Scope& sconns = *econns->Compound();
+    const ElementCollection conns = sconns.GetCollection("C");
+    for(ElementMap::const_iterator it = conns.first; it != conns.second; ++it) {
+        const Element& el = *(*it).second;
+        const std::string& type = ParseTokenAsString(GetRequiredToken(el,0));
+
+        // PP = property-property connection, ignored for now
+        // (tokens: "PP", ID1, "Property1", ID2, "Property2")
+        if ( type == "PP" ) {
+            continue;
+        }
+
+        const uint64_t src = ParseTokenAsID(GetRequiredToken(el,1));
+        const uint64_t dest = ParseTokenAsID(GetRequiredToken(el,2));
+
+        // OO = object-object connection
+        // OP = object-property connection, in which case the destination property follows the object ID
+        const std::string& prop = (type == "OP" ? ParseTokenAsString(GetRequiredToken(el,3)) : "");
+
+        if(objects.find(src) == objects.end()) {
+            DOMWarning("source object for connection does not exist",&el);
+            continue;
+        }
+
+        // dest may be 0 (root node) but we added a dummy object before
+        if(objects.find(dest) == objects.end()) {
+            DOMWarning("destination object for connection does not exist",&el);
+            continue;
+        }
+
+        // add new connection
+        const Connection* const c = new Connection(insertionOrder++,src,dest,prop,*this);
+        src_connections.insert(ConnectionMap::value_type(src,c));
+        dest_connections.insert(ConnectionMap::value_type(dest,c));
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+const std::vector<const AnimationStack*>& Document::AnimationStacks() const
+{
+    if (!animationStacksResolved.empty() || animationStacks.empty()) {
+        return animationStacksResolved;
+    }
+
+    animationStacksResolved.reserve(animationStacks.size());
+    for(uint64_t id : animationStacks) {
+        LazyObject* const lazy = GetObject(id);
+        const AnimationStack* stack;
+        if(!lazy || !(stack = lazy->Get<AnimationStack>())) {
+            DOMWarning("failed to read AnimationStack object");
+            continue;
+        }
+        animationStacksResolved.push_back(stack);
+    }
+
+    return animationStacksResolved;
+}
+
+// ------------------------------------------------------------------------------------------------
+LazyObject* Document::GetObject(uint64_t id) const
+{
+    ObjectMap::const_iterator it = objects.find(id);
+    return it == objects.end() ? nullptr : (*it).second;
+}
+
+#define MAX_CLASSNAMES 6
+
+// ------------------------------------------------------------------------------------------------
+std::vector<const Connection*> Document::GetConnectionsSequenced(uint64_t id, const ConnectionMap& conns) const
+{
+    std::vector<const Connection*> temp;
+
+    const std::pair<ConnectionMap::const_iterator,ConnectionMap::const_iterator> range =
+        conns.equal_range(id);
+
+    temp.reserve(std::distance(range.first,range.second));
+    for (ConnectionMap::const_iterator it = range.first; it != range.second; ++it) {
+        temp.push_back((*it).second);
+    }
+
+    std::sort(temp.begin(), temp.end(), std::mem_fn(&Connection::Compare));
+
+    return temp; // NRVO should handle this
+}
+
+// ------------------------------------------------------------------------------------------------
+std::vector<const Connection*> Document::GetConnectionsSequenced(uint64_t id, bool is_src,
+    const ConnectionMap& conns,
+    const char* const* classnames,
+    size_t count) const
+
+{
+    ai_assert(classnames);
+    ai_assert( count != 0 );
+    ai_assert( count <= MAX_CLASSNAMES);
+
+    size_t lengths[MAX_CLASSNAMES];
+
+    const size_t c = count;
+    for (size_t i = 0; i < c; ++i) {
+        lengths[ i ] = strlen(classnames[i]);
+    }
+
+    std::vector<const Connection*> temp;
+    const std::pair<ConnectionMap::const_iterator,ConnectionMap::const_iterator> range =
+        conns.equal_range(id);
+
+    temp.reserve(std::distance(range.first,range.second));
+    for (ConnectionMap::const_iterator it = range.first; it != range.second; ++it) {
+        const Token& key = (is_src
+            ? (*it).second->LazyDestinationObject()
+            : (*it).second->LazySourceObject()
+        ).GetElement().KeyToken();
+
+        const char* obtype = key.begin();
+
+        for (size_t i = 0; i < c; ++i) {
+            ai_assert(classnames[i]);
+            if(static_cast<size_t>(std::distance(key.begin(),key.end())) == lengths[i] && !strncmp(classnames[i],obtype,lengths[i])) {
+                obtype = nullptr;
+                break;
+            }
+        }
+
+        if(obtype) {
+            continue;
+        }
+
+        temp.push_back((*it).second);
+    }
+
+    std::sort(temp.begin(), temp.end(), std::mem_fn(&Connection::Compare));
+    return temp; // NRVO should handle this
+}
+
+// ------------------------------------------------------------------------------------------------
+std::vector<const Connection*> Document::GetConnectionsBySourceSequenced(uint64_t source) const
+{
+    return GetConnectionsSequenced(source, ConnectionsBySource());
+}
+
+// ------------------------------------------------------------------------------------------------
+std::vector<const Connection*> Document::GetConnectionsBySourceSequenced(uint64_t src, const char* classname) const
+{
+    const char* arr[] = {classname};
+    return GetConnectionsBySourceSequenced(src, arr,1);
+}
+
+// ------------------------------------------------------------------------------------------------
+std::vector<const Connection*> Document::GetConnectionsBySourceSequenced(uint64_t source, 
+        const char* const* classnames, size_t count) const
+{
+    return GetConnectionsSequenced(source, true, ConnectionsBySource(),classnames, count);
+}
+
+// ------------------------------------------------------------------------------------------------
+std::vector<const Connection*> Document::GetConnectionsByDestinationSequenced(uint64_t dest,
+        const char* classname) const
+{
+    const char* arr[] = {classname};
+    return GetConnectionsByDestinationSequenced(dest, arr,1);
+}
+
+// ------------------------------------------------------------------------------------------------
+std::vector<const Connection*> Document::GetConnectionsByDestinationSequenced(uint64_t dest) const
+{
+    return GetConnectionsSequenced(dest, ConnectionsByDestination());
+}
+
+// ------------------------------------------------------------------------------------------------
+std::vector<const Connection*> Document::GetConnectionsByDestinationSequenced(uint64_t dest,
+    const char* const* classnames, size_t count) const
+
+{
+    return GetConnectionsSequenced(dest, false, ConnectionsByDestination(),classnames, count);
+}
+
+// ------------------------------------------------------------------------------------------------
+Connection::Connection(uint64_t insertionOrder,  uint64_t src, uint64_t dest, const std::string& prop,
+        const Document& doc)
+
+: insertionOrder(insertionOrder)
+, prop(prop)
+, src(src)
+, dest(dest)
+, doc(doc)
+{
+    ai_assert(doc.Objects().find(src) != doc.Objects().end());
+    // dest may be 0 (root node)
+    ai_assert(!dest || doc.Objects().find(dest) != doc.Objects().end());
+}
+
+// ------------------------------------------------------------------------------------------------
+Connection::~Connection()
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+LazyObject& Connection::LazySourceObject() const
+{
+    LazyObject* const lazy = doc.GetObject(src);
+    ai_assert(lazy);
+    return *lazy;
+}
+
+// ------------------------------------------------------------------------------------------------
+LazyObject& Connection::LazyDestinationObject() const
+{
+    LazyObject* const lazy = doc.GetObject(dest);
+    ai_assert(lazy);
+    return *lazy;
+}
+
+// ------------------------------------------------------------------------------------------------
+const Object* Connection::SourceObject() const
+{
+    LazyObject* const lazy = doc.GetObject(src);
+    ai_assert(lazy);
+    return lazy->Get();
+}
+
+// ------------------------------------------------------------------------------------------------
+const Object* Connection::DestinationObject() const
+{
+    LazyObject* const lazy = doc.GetObject(dest);
+    ai_assert(lazy);
+    return lazy->Get();
+}
+
+} // !FBX
+} // !Assimp
+
+#endif
diff --git a/thirdparty/assimp/code/FBX/FBXDocument.h b/thirdparty/assimp/code/FBX/FBXDocument.h
new file mode 100644
index 0000000000..18e5c38f13
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXDocument.h
@@ -0,0 +1,1180 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXDocument.h
+ *  @brief FBX DOM
+ */
+#ifndef INCLUDED_AI_FBX_DOCUMENT_H
+#define INCLUDED_AI_FBX_DOCUMENT_H
+
+#include <numeric>
+#include <stdint.h>
+#include <assimp/mesh.h>
+#include "FBXProperties.h"
+#include "FBXParser.h"
+
+#define _AI_CONCAT(a,b)  a ## b
+#define  AI_CONCAT(a,b)  _AI_CONCAT(a,b)
+
+namespace Assimp {
+namespace FBX {
+
+class Parser;
+class Object;
+struct ImportSettings;
+
+class PropertyTable;
+class Document;
+class Material;
+class ShapeGeometry;
+class LineGeometry;
+class Geometry;
+
+class Video;
+
+class AnimationCurve;
+class AnimationCurveNode;
+class AnimationLayer;
+class AnimationStack;
+
+class BlendShapeChannel;
+class BlendShape;
+class Skin;
+class Cluster;
+
+
+/** Represents a delay-parsed FBX objects. Many objects in the scene
+ *  are not needed by assimp, so it makes no sense to parse them
+ *  upfront. */
+class LazyObject {
+public:
+    LazyObject(uint64_t id, const Element& element, const Document& doc);
+
+    ~LazyObject();
+
+    const Object* Get(bool dieOnError = false);
+
+    template <typename T>
+    const T* Get(bool dieOnError = false) {
+        const Object* const ob = Get(dieOnError);
+        return ob ? dynamic_cast<const T*>(ob) : NULL;
+    }
+
+    uint64_t ID() const {
+        return id;
+    }
+
+    bool IsBeingConstructed() const {
+        return (flags & BEING_CONSTRUCTED) != 0;
+    }
+
+    bool FailedToConstruct() const {
+        return (flags & FAILED_TO_CONSTRUCT) != 0;
+    }
+
+    const Element& GetElement() const {
+        return element;
+    }
+
+    const Document& GetDocument() const {
+        return doc;
+    }
+
+private:
+    const Document& doc;
+    const Element& element;
+    std::unique_ptr<const Object> object;
+
+    const uint64_t id;
+
+    enum Flags {
+        BEING_CONSTRUCTED = 0x1,
+        FAILED_TO_CONSTRUCT = 0x2
+    };
+
+    unsigned int flags;
+};
+
+/** Base class for in-memory (DOM) representations of FBX objects */
+class Object {
+public:
+    Object(uint64_t id, const Element& element, const std::string& name);
+
+    virtual ~Object();
+
+    const Element& SourceElement() const {
+        return element;
+    }
+
+    const std::string& Name() const {
+        return name;
+    }
+
+    uint64_t ID() const {
+        return id;
+    }
+
+protected:
+    const Element& element;
+    const std::string name;
+    const uint64_t id;
+};
+
+/** DOM class for generic FBX NoteAttribute blocks. NoteAttribute's just hold a property table,
+ *  fixed members are added by deriving classes. */
+class NodeAttribute : public Object {
+public:
+    NodeAttribute(uint64_t id, const Element& element, const Document& doc, const std::string& name);
+
+    virtual ~NodeAttribute();
+
+    const PropertyTable& Props() const {
+        ai_assert(props.get());
+        return *props.get();
+    }
+
+private:
+    std::shared_ptr<const PropertyTable> props;
+};
+
+/** DOM base class for FBX camera settings attached to a node */
+class CameraSwitcher : public NodeAttribute {
+public:
+    CameraSwitcher(uint64_t id, const Element& element, const Document& doc, const std::string& name);
+
+    virtual ~CameraSwitcher();
+
+    int CameraID() const {
+        return cameraId;
+    }
+
+    const std::string& CameraName() const {
+        return cameraName;
+    }
+
+    const std::string& CameraIndexName() const {
+        return cameraIndexName;
+    }
+
+private:
+    int cameraId;
+    std::string cameraName;
+    std::string cameraIndexName;
+};
+
+#define fbx_stringize(a) #a
+
+#define fbx_simple_property(name, type, default_value) \
+    type name() const { \
+        return PropertyGet<type>(Props(), fbx_stringize(name), (default_value)); \
+    }
+
+// XXX improve logging
+#define fbx_simple_enum_property(name, type, default_value) \
+    type name() const { \
+        const int ival = PropertyGet<int>(Props(), fbx_stringize(name), static_cast<int>(default_value)); \
+        if (ival < 0 || ival >= AI_CONCAT(type, _MAX)) { \
+            ai_assert(static_cast<int>(default_value) >= 0 && static_cast<int>(default_value) < AI_CONCAT(type, _MAX)); \
+            return static_cast<type>(default_value); \
+        } \
+        return static_cast<type>(ival); \
+}
+
+
+/** DOM base class for FBX cameras attached to a node */
+class Camera : public NodeAttribute {
+public:
+    Camera(uint64_t id, const Element& element, const Document& doc, const std::string& name);
+
+    virtual  ~Camera();
+
+    fbx_simple_property(Position, aiVector3D, aiVector3D(0,0,0))
+    fbx_simple_property(UpVector, aiVector3D, aiVector3D(0,1,0))
+    fbx_simple_property(InterestPosition, aiVector3D, aiVector3D(0,0,0))
+
+    fbx_simple_property(AspectWidth, float, 1.0f)
+    fbx_simple_property(AspectHeight, float, 1.0f)
+    fbx_simple_property(FilmWidth, float, 1.0f)
+    fbx_simple_property(FilmHeight, float, 1.0f)
+
+    fbx_simple_property(NearPlane, float, 0.1f)
+    fbx_simple_property(FarPlane, float, 100.0f)
+
+    fbx_simple_property(FilmAspectRatio, float, 1.0f)
+    fbx_simple_property(ApertureMode, int, 0)
+
+    fbx_simple_property(FieldOfView, float, 1.0f)
+    fbx_simple_property(FocalLength, float, 1.0f)
+};
+
+/** DOM base class for FBX null markers attached to a node */
+class Null : public NodeAttribute {
+public:
+    Null(uint64_t id, const Element& element, const Document& doc, const std::string& name);
+    virtual ~Null();
+};
+
+/** DOM base class for FBX limb node markers attached to a node */
+class LimbNode : public NodeAttribute {
+public:
+    LimbNode(uint64_t id, const Element& element, const Document& doc, const std::string& name);
+    virtual ~LimbNode();
+};
+
+/** DOM base class for FBX lights attached to a node */
+class Light : public NodeAttribute {
+public:
+    Light(uint64_t id, const Element& element, const Document& doc, const std::string& name);
+    virtual ~Light();
+
+    enum Type
+    {
+        Type_Point,
+        Type_Directional,
+        Type_Spot,
+        Type_Area,
+        Type_Volume,
+
+        Type_MAX // end-of-enum sentinel
+    };
+
+    enum Decay
+    {
+        Decay_None,
+        Decay_Linear,
+        Decay_Quadratic,
+        Decay_Cubic,
+
+        Decay_MAX // end-of-enum sentinel
+    };
+
+    fbx_simple_property(Color, aiVector3D, aiVector3D(1,1,1))
+    fbx_simple_enum_property(LightType, Type, 0)
+    fbx_simple_property(CastLightOnObject, bool, false)
+    fbx_simple_property(DrawVolumetricLight, bool, true)
+    fbx_simple_property(DrawGroundProjection, bool, true)
+    fbx_simple_property(DrawFrontFacingVolumetricLight, bool, false)
+    fbx_simple_property(Intensity, float, 100.0f)
+    fbx_simple_property(InnerAngle, float, 0.0f)
+    fbx_simple_property(OuterAngle, float, 45.0f)
+    fbx_simple_property(Fog, int, 50)
+    fbx_simple_enum_property(DecayType, Decay, 2)
+    fbx_simple_property(DecayStart, float, 1.0f)
+    fbx_simple_property(FileName, std::string, "")
+
+    fbx_simple_property(EnableNearAttenuation, bool, false)
+    fbx_simple_property(NearAttenuationStart, float, 0.0f)
+    fbx_simple_property(NearAttenuationEnd, float, 0.0f)
+    fbx_simple_property(EnableFarAttenuation, bool, false)
+    fbx_simple_property(FarAttenuationStart, float, 0.0f)
+    fbx_simple_property(FarAttenuationEnd, float, 0.0f)
+
+    fbx_simple_property(CastShadows, bool, true)
+    fbx_simple_property(ShadowColor, aiVector3D, aiVector3D(0,0,0))
+
+    fbx_simple_property(AreaLightShape, int, 0)
+
+    fbx_simple_property(LeftBarnDoor, float, 20.0f)
+    fbx_simple_property(RightBarnDoor, float, 20.0f)
+    fbx_simple_property(TopBarnDoor, float, 20.0f)
+    fbx_simple_property(BottomBarnDoor, float, 20.0f)
+    fbx_simple_property(EnableBarnDoor, bool, true)
+};
+
+/** DOM base class for FBX models (even though its semantics are more "node" than "model" */
+class Model : public Object {
+public:
+    enum RotOrder {
+        RotOrder_EulerXYZ = 0,
+        RotOrder_EulerXZY,
+        RotOrder_EulerYZX,
+        RotOrder_EulerYXZ,
+        RotOrder_EulerZXY,
+        RotOrder_EulerZYX,
+
+        RotOrder_SphericXYZ,
+
+        RotOrder_MAX // end-of-enum sentinel
+    };
+
+    enum TransformInheritance {
+        TransformInheritance_RrSs = 0,
+        TransformInheritance_RSrs,
+        TransformInheritance_Rrs,
+
+        TransformInheritance_MAX // end-of-enum sentinel
+    };
+
+    Model(uint64_t id, const Element& element, const Document& doc, const std::string& name);
+
+    virtual ~Model();
+
+    fbx_simple_property(QuaternionInterpolate, int, 0)
+
+    fbx_simple_property(RotationOffset, aiVector3D, aiVector3D())
+    fbx_simple_property(RotationPivot, aiVector3D, aiVector3D())
+    fbx_simple_property(ScalingOffset, aiVector3D, aiVector3D())
+    fbx_simple_property(ScalingPivot, aiVector3D, aiVector3D())
+    fbx_simple_property(TranslationActive, bool, false)
+
+    fbx_simple_property(TranslationMin, aiVector3D, aiVector3D())
+    fbx_simple_property(TranslationMax, aiVector3D, aiVector3D())
+
+    fbx_simple_property(TranslationMinX, bool, false)
+    fbx_simple_property(TranslationMaxX, bool, false)
+    fbx_simple_property(TranslationMinY, bool, false)
+    fbx_simple_property(TranslationMaxY, bool, false)
+    fbx_simple_property(TranslationMinZ, bool, false)
+    fbx_simple_property(TranslationMaxZ, bool, false)
+
+    fbx_simple_enum_property(RotationOrder, RotOrder, 0)
+    fbx_simple_property(RotationSpaceForLimitOnly, bool, false)
+    fbx_simple_property(RotationStiffnessX, float, 0.0f)
+    fbx_simple_property(RotationStiffnessY, float, 0.0f)
+    fbx_simple_property(RotationStiffnessZ, float, 0.0f)
+    fbx_simple_property(AxisLen, float, 0.0f)
+
+    fbx_simple_property(PreRotation, aiVector3D, aiVector3D())
+    fbx_simple_property(PostRotation, aiVector3D, aiVector3D())
+    fbx_simple_property(RotationActive, bool, false)
+
+    fbx_simple_property(RotationMin, aiVector3D, aiVector3D())
+    fbx_simple_property(RotationMax, aiVector3D, aiVector3D())
+
+    fbx_simple_property(RotationMinX, bool, false)
+    fbx_simple_property(RotationMaxX, bool, false)
+    fbx_simple_property(RotationMinY, bool, false)
+    fbx_simple_property(RotationMaxY, bool, false)
+    fbx_simple_property(RotationMinZ, bool, false)
+    fbx_simple_property(RotationMaxZ, bool, false)
+    fbx_simple_enum_property(InheritType, TransformInheritance, 0)
+
+    fbx_simple_property(ScalingActive, bool, false)
+    fbx_simple_property(ScalingMin, aiVector3D, aiVector3D())
+    fbx_simple_property(ScalingMax, aiVector3D, aiVector3D(1.f,1.f,1.f))
+    fbx_simple_property(ScalingMinX, bool, false)
+    fbx_simple_property(ScalingMaxX, bool, false)
+    fbx_simple_property(ScalingMinY, bool, false)
+    fbx_simple_property(ScalingMaxY, bool, false)
+    fbx_simple_property(ScalingMinZ, bool, false)
+    fbx_simple_property(ScalingMaxZ, bool, false)
+
+    fbx_simple_property(GeometricTranslation, aiVector3D, aiVector3D())
+    fbx_simple_property(GeometricRotation, aiVector3D, aiVector3D())
+    fbx_simple_property(GeometricScaling, aiVector3D, aiVector3D(1.f, 1.f, 1.f))
+
+    fbx_simple_property(MinDampRangeX, float, 0.0f)
+    fbx_simple_property(MinDampRangeY, float, 0.0f)
+    fbx_simple_property(MinDampRangeZ, float, 0.0f)
+    fbx_simple_property(MaxDampRangeX, float, 0.0f)
+    fbx_simple_property(MaxDampRangeY, float, 0.0f)
+    fbx_simple_property(MaxDampRangeZ, float, 0.0f)
+
+    fbx_simple_property(MinDampStrengthX, float, 0.0f)
+    fbx_simple_property(MinDampStrengthY, float, 0.0f)
+    fbx_simple_property(MinDampStrengthZ, float, 0.0f)
+    fbx_simple_property(MaxDampStrengthX, float, 0.0f)
+    fbx_simple_property(MaxDampStrengthY, float, 0.0f)
+    fbx_simple_property(MaxDampStrengthZ, float, 0.0f)
+
+    fbx_simple_property(PreferredAngleX, float, 0.0f)
+    fbx_simple_property(PreferredAngleY, float, 0.0f)
+    fbx_simple_property(PreferredAngleZ, float, 0.0f)
+
+    fbx_simple_property(Show, bool, true)
+    fbx_simple_property(LODBox, bool, false)
+    fbx_simple_property(Freeze, bool, false)
+
+    const std::string& Shading() const {
+        return shading;
+    }
+
+    const std::string& Culling() const {
+        return culling;
+    }
+
+    const PropertyTable& Props() const {
+        ai_assert(props.get());
+        return *props.get();
+    }
+
+    /** Get material links */
+    const std::vector<const Material*>& GetMaterials() const {
+        return materials;
+    }
+
+    /** Get geometry links */
+    const std::vector<const Geometry*>& GetGeometry() const {
+        return geometry;
+    }
+
+    /** Get node attachments */
+    const std::vector<const NodeAttribute*>& GetAttributes() const {
+        return attributes;
+    }
+
+    /** convenience method to check if the node has a Null node marker */
+    bool IsNull() const;
+
+private:
+    void ResolveLinks(const Element& element, const Document& doc);
+
+private:
+    std::vector<const Material*> materials;
+    std::vector<const Geometry*> geometry;
+    std::vector<const NodeAttribute*> attributes;
+
+    std::string shading;
+    std::string culling;
+    std::shared_ptr<const PropertyTable> props;
+};
+
+/** DOM class for generic FBX textures */
+class Texture : public Object {
+public:
+    Texture(uint64_t id, const Element& element, const Document& doc, const std::string& name);
+
+    virtual ~Texture();
+
+    const std::string& Type() const {
+        return type;
+    }
+
+    const std::string& FileName() const {
+        return fileName;
+    }
+
+    const std::string& RelativeFilename() const {
+        return relativeFileName;
+    }
+
+    const std::string& AlphaSource() const {
+        return alphaSource;
+    }
+
+    const aiVector2D& UVTranslation() const {
+        return uvTrans;
+    }
+
+    const aiVector2D& UVScaling() const {
+        return uvScaling;
+    }
+
+    const PropertyTable& Props() const {
+        ai_assert(props.get());
+        return *props.get();
+    }
+
+    // return a 4-tuple
+    const unsigned int* Crop() const {
+        return crop;
+    }
+
+    const Video* Media() const {
+        return media;
+    }
+
+private:
+    aiVector2D uvTrans;
+    aiVector2D uvScaling;
+
+    std::string type;
+    std::string relativeFileName;
+    std::string fileName;
+    std::string alphaSource;
+    std::shared_ptr<const PropertyTable> props;
+
+    unsigned int crop[4];
+
+    const Video* media;
+};
+
+/** DOM class for layered FBX textures */
+class LayeredTexture : public Object {
+public:
+    LayeredTexture(uint64_t id, const Element& element, const Document& doc, const std::string& name);
+    virtual ~LayeredTexture();
+
+    // Can only be called after construction of the layered texture object due to construction flag.
+    void fillTexture(const Document& doc);
+
+    enum BlendMode {
+        BlendMode_Translucent,
+        BlendMode_Additive,
+        BlendMode_Modulate,
+        BlendMode_Modulate2,
+        BlendMode_Over,
+        BlendMode_Normal,
+        BlendMode_Dissolve,
+        BlendMode_Darken,
+        BlendMode_ColorBurn,
+        BlendMode_LinearBurn,
+        BlendMode_DarkerColor,
+        BlendMode_Lighten,
+        BlendMode_Screen,
+        BlendMode_ColorDodge,
+        BlendMode_LinearDodge,
+        BlendMode_LighterColor,
+        BlendMode_SoftLight,
+        BlendMode_HardLight,
+        BlendMode_VividLight,
+        BlendMode_LinearLight,
+        BlendMode_PinLight,
+        BlendMode_HardMix,
+        BlendMode_Difference,
+        BlendMode_Exclusion,
+        BlendMode_Subtract,
+        BlendMode_Divide,
+        BlendMode_Hue,
+        BlendMode_Saturation,
+        BlendMode_Color,
+        BlendMode_Luminosity,
+        BlendMode_Overlay,
+        BlendMode_BlendModeCount
+    };
+
+    const Texture* getTexture(int index=0) const
+    {
+		return textures[index];
+
+    }
+	int textureCount() const {
+		return static_cast<int>(textures.size());
+	}
+    BlendMode GetBlendMode() const
+    {
+        return blendMode;
+    }
+    float Alpha()
+    {
+        return alpha;
+    }
+private:
+	std::vector<const Texture*> textures;
+    BlendMode blendMode;
+    float alpha;
+};
+
+typedef std::fbx_unordered_map<std::string, const Texture*> TextureMap;
+typedef std::fbx_unordered_map<std::string, const LayeredTexture*> LayeredTextureMap;
+
+
+/** DOM class for generic FBX videos */
+class Video : public Object {
+public:
+    Video(uint64_t id, const Element& element, const Document& doc, const std::string& name);
+
+    virtual ~Video();
+
+    const std::string& Type() const {
+        return type;
+    }
+
+    const std::string& FileName() const {
+        return fileName;
+    }
+
+    const std::string& RelativeFilename() const {
+        return relativeFileName;
+    }
+
+    const PropertyTable& Props() const {
+        ai_assert(props.get());
+        return *props.get();
+    }
+
+    const uint8_t* Content() const {
+        ai_assert(content);
+        return content;
+    }
+
+    uint64_t ContentLength() const {
+        return contentLength;
+    }
+
+    uint8_t* RelinquishContent() {
+        uint8_t* ptr = content;
+        content = 0;
+        return ptr;
+    }
+
+private:
+    std::string type;
+    std::string relativeFileName;
+    std::string fileName;
+    std::shared_ptr<const PropertyTable> props;
+
+    uint64_t contentLength;
+    uint8_t* content;
+};
+
+/** DOM class for generic FBX materials */
+class Material : public Object {
+public:
+    Material(uint64_t id, const Element& element, const Document& doc, const std::string& name);
+
+    virtual ~Material();
+
+    const std::string& GetShadingModel() const {
+        return shading;
+    }
+
+    bool IsMultilayer() const {
+        return multilayer;
+    }
+
+    const PropertyTable& Props() const {
+        ai_assert(props.get());
+        return *props.get();
+    }
+
+    const TextureMap& Textures() const {
+        return textures;
+    }
+
+    const LayeredTextureMap& LayeredTextures() const {
+        return layeredTextures;
+    }
+
+private:
+    std::string shading;
+    bool multilayer;
+    std::shared_ptr<const PropertyTable> props;
+
+    TextureMap textures;
+    LayeredTextureMap layeredTextures;
+};
+
+typedef std::vector<int64_t> KeyTimeList;
+typedef std::vector<float> KeyValueList;
+
+/** Represents a FBX animation curve (i.e. a 1-dimensional set of keyframes and values therefor) */
+class AnimationCurve : public Object {
+public:
+    AnimationCurve(uint64_t id, const Element& element, const std::string& name, const Document& doc);
+    virtual ~AnimationCurve();
+
+    /** get list of keyframe positions (time).
+     *  Invariant: |GetKeys()| > 0 */
+    const KeyTimeList& GetKeys() const {
+        return keys;
+    }
+
+    /** get list of keyframe values.
+      * Invariant: |GetKeys()| == |GetValues()| && |GetKeys()| > 0*/
+    const KeyValueList& GetValues() const {
+        return values;
+    }
+
+    const std::vector<float>& GetAttributes() const {
+        return attributes;
+    }
+
+    const std::vector<unsigned int>& GetFlags() const {
+        return flags;
+    }
+
+private:
+    KeyTimeList keys;
+    KeyValueList values;
+    std::vector<float> attributes;
+    std::vector<unsigned int> flags;
+};
+
+// property-name -> animation curve
+typedef std::map<std::string, const AnimationCurve*> AnimationCurveMap;
+
+/** Represents a FBX animation curve (i.e. a mapping from single animation curves to nodes) */
+class AnimationCurveNode : public Object {
+public:
+    /* the optional white list specifies a list of property names for which the caller
+    wants animations for. If the curve node does not match one of these, std::range_error
+    will be thrown. */
+    AnimationCurveNode(uint64_t id, const Element& element, const std::string& name, const Document& doc,
+        const char* const * target_prop_whitelist = NULL, size_t whitelist_size = 0);
+
+    virtual ~AnimationCurveNode();
+
+    const PropertyTable& Props() const {
+        ai_assert(props.get());
+        return *props.get();
+    }
+
+
+    const AnimationCurveMap& Curves() const;
+
+    /** Object the curve is assigned to, this can be NULL if the
+     *  target object has no DOM representation or could not
+     *  be read for other reasons.*/
+    const Object* Target() const {
+        return target;
+    }
+
+    const Model* TargetAsModel() const {
+        return dynamic_cast<const Model*>(target);
+    }
+
+    const NodeAttribute* TargetAsNodeAttribute() const {
+        return dynamic_cast<const NodeAttribute*>(target);
+    }
+
+    /** Property of Target() that is being animated*/
+    const std::string& TargetProperty() const {
+        return prop;
+    }
+
+private:
+    const Object* target;
+    std::shared_ptr<const PropertyTable> props;
+    mutable AnimationCurveMap curves;
+
+    std::string prop;
+    const Document& doc;
+};
+
+typedef std::vector<const AnimationCurveNode*> AnimationCurveNodeList;
+
+/** Represents a FBX animation layer (i.e. a list of node animations) */
+class AnimationLayer : public Object {
+public:
+    AnimationLayer(uint64_t id, const Element& element, const std::string& name, const Document& doc);
+    virtual ~AnimationLayer();
+
+    const PropertyTable& Props() const {
+        ai_assert(props.get());
+        return *props.get();
+    }
+
+    /* the optional white list specifies a list of property names for which the caller
+    wants animations for. Curves not matching this list will not be added to the
+    animation layer. */
+    AnimationCurveNodeList Nodes(const char* const * target_prop_whitelist = nullptr, size_t whitelist_size = 0) const;
+
+private:
+    std::shared_ptr<const PropertyTable> props;
+    const Document& doc;
+};
+
+typedef std::vector<const AnimationLayer*> AnimationLayerList;
+
+/** Represents a FBX animation stack (i.e. a list of animation layers) */
+class AnimationStack : public Object {
+public:
+    AnimationStack(uint64_t id, const Element& element, const std::string& name, const Document& doc);
+    virtual ~AnimationStack();
+
+    fbx_simple_property(LocalStart, int64_t, 0L)
+    fbx_simple_property(LocalStop, int64_t, 0L)
+    fbx_simple_property(ReferenceStart, int64_t, 0L)
+    fbx_simple_property(ReferenceStop, int64_t, 0L)
+
+    const PropertyTable& Props() const {
+        ai_assert(props.get());
+        return *props.get();
+    }
+
+    const AnimationLayerList& Layers() const {
+        return layers;
+    }
+
+private:
+    std::shared_ptr<const PropertyTable> props;
+    AnimationLayerList layers;
+};
+
+
+/** DOM class for deformers */
+class Deformer : public Object {
+public:
+    Deformer(uint64_t id, const Element& element, const Document& doc, const std::string& name);
+    virtual ~Deformer();
+
+    const PropertyTable& Props() const {
+        ai_assert(props.get());
+        return *props.get();
+    }
+
+private:
+    std::shared_ptr<const PropertyTable> props;
+};
+
+typedef std::vector<float> WeightArray;
+typedef std::vector<unsigned int> WeightIndexArray;
+
+
+/** DOM class for BlendShapeChannel deformers */
+class BlendShapeChannel : public Deformer {
+public:
+    BlendShapeChannel(uint64_t id, const Element& element, const Document& doc, const std::string& name);
+
+    virtual ~BlendShapeChannel();
+
+    float DeformPercent() const {
+        return percent;
+    }
+
+    const WeightArray& GetFullWeights() const {
+        return fullWeights;
+    }
+
+    const std::vector<const ShapeGeometry*>& GetShapeGeometries() const {
+        return shapeGeometries;
+    }
+
+private:
+    float percent;
+    WeightArray fullWeights;
+    std::vector<const ShapeGeometry*> shapeGeometries;
+};
+
+/** DOM class for BlendShape deformers */
+class BlendShape : public Deformer {
+public:
+    BlendShape(uint64_t id, const Element& element, const Document& doc, const std::string& name);
+
+    virtual ~BlendShape();
+
+    const std::vector<const BlendShapeChannel*>& BlendShapeChannels() const {
+        return blendShapeChannels;
+    }
+
+private:
+    std::vector<const BlendShapeChannel*> blendShapeChannels;
+};
+
+/** DOM class for skin deformer clusters (aka sub-deformers) */
+class Cluster : public Deformer {
+public:
+    Cluster(uint64_t id, const Element& element, const Document& doc, const std::string& name);
+
+    virtual ~Cluster();
+
+    /** get the list of deformer weights associated with this cluster.
+     *  Use #GetIndices() to get the associated vertices. Both arrays
+     *  have the same size (and may also be empty). */
+    const WeightArray& GetWeights() const {
+        return weights;
+    }
+
+    /** get indices into the vertex data of the geometry associated
+     *  with this cluster. Use #GetWeights() to get the associated weights.
+     *  Both arrays have the same size (and may also be empty). */
+    const WeightIndexArray& GetIndices() const {
+        return indices;
+    }
+
+    /** */
+    const aiMatrix4x4& Transform() const {
+        return transform;
+    }
+
+    const aiMatrix4x4& TransformLink() const {
+        return transformLink;
+    }
+
+    const Model* TargetNode() const {
+        return node;
+    }
+
+private:
+    WeightArray weights;
+    WeightIndexArray indices;
+
+    aiMatrix4x4 transform;
+    aiMatrix4x4 transformLink;
+
+    const Model* node;
+};
+
+/** DOM class for skin deformers */
+class Skin : public Deformer {
+public:
+    Skin(uint64_t id, const Element& element, const Document& doc, const std::string& name);
+
+    virtual ~Skin();
+
+    float DeformAccuracy() const {
+        return accuracy;
+    }
+
+    const std::vector<const Cluster*>& Clusters() const {
+        return clusters;
+    }
+
+private:
+    float accuracy;
+    std::vector<const Cluster*> clusters;
+};
+
+/** Represents a link between two FBX objects. */
+class Connection {
+public:
+    Connection(uint64_t insertionOrder,  uint64_t src, uint64_t dest, const std::string& prop, const Document& doc);
+
+    ~Connection();
+
+    // note: a connection ensures that the source and dest objects exist, but
+    // not that they have DOM representations, so the return value of one of
+    // these functions can still be NULL.
+    const Object* SourceObject() const;
+    const Object* DestinationObject() const;
+
+    // these, however, are always guaranteed to be valid
+    LazyObject& LazySourceObject() const;
+    LazyObject& LazyDestinationObject() const;
+
+
+    /** return the name of the property the connection is attached to.
+      * this is an empty string for object to object (OO) connections. */
+    const std::string& PropertyName() const {
+        return prop;
+    }
+
+    uint64_t InsertionOrder() const {
+        return insertionOrder;
+    }
+
+    int CompareTo(const Connection* c) const {
+        ai_assert( nullptr != c );
+
+        // note: can't subtract because this would overflow uint64_t
+        if(InsertionOrder() > c->InsertionOrder()) {
+            return 1;
+        }
+        else if(InsertionOrder() < c->InsertionOrder()) {
+            return -1;
+        }
+        return 0;
+    }
+
+    bool Compare(const Connection* c) const {
+        ai_assert( nullptr != c );
+
+        return InsertionOrder() < c->InsertionOrder();
+    }
+
+public:
+    uint64_t insertionOrder;
+    const std::string prop;
+
+    uint64_t src, dest;
+    const Document& doc;
+};
+
+// XXX again, unique_ptr would be useful. shared_ptr is too
+// bloated since the objects have a well-defined single owner
+// during their entire lifetime (Document). FBX files have
+// up to many thousands of objects (most of which we never use),
+// so the memory overhead for them should be kept at a minimum.
+typedef std::map<uint64_t, LazyObject*> ObjectMap;
+typedef std::fbx_unordered_map<std::string, std::shared_ptr<const PropertyTable> > PropertyTemplateMap;
+
+typedef std::multimap<uint64_t, const Connection*> ConnectionMap;
+
+/** DOM class for global document settings, a single instance per document can
+ *  be accessed via Document.Globals(). */
+class FileGlobalSettings {
+public:
+    FileGlobalSettings(const Document& doc, std::shared_ptr<const PropertyTable> props);
+
+    ~FileGlobalSettings();
+
+    const PropertyTable& Props() const {
+        ai_assert(props.get());
+        return *props.get();
+    }
+
+    const Document& GetDocument() const {
+        return doc;
+    }
+
+    fbx_simple_property(UpAxis, int, 1)
+    fbx_simple_property(UpAxisSign, int, 1)
+    fbx_simple_property(FrontAxis, int, 2)
+    fbx_simple_property(FrontAxisSign, int, 1)
+    fbx_simple_property(CoordAxis, int, 0)
+    fbx_simple_property(CoordAxisSign, int, 1)
+    fbx_simple_property(OriginalUpAxis, int, 0)
+    fbx_simple_property(OriginalUpAxisSign, int, 1)
+    fbx_simple_property(UnitScaleFactor, float, 1)
+    fbx_simple_property(OriginalUnitScaleFactor, float, 1)
+    fbx_simple_property(AmbientColor, aiVector3D, aiVector3D(0,0,0))
+    fbx_simple_property(DefaultCamera, std::string, "")
+
+
+    enum FrameRate {
+        FrameRate_DEFAULT = 0,
+        FrameRate_120 = 1,
+        FrameRate_100 = 2,
+        FrameRate_60 = 3,
+        FrameRate_50 = 4,
+        FrameRate_48 = 5,
+        FrameRate_30 = 6,
+        FrameRate_30_DROP = 7,
+        FrameRate_NTSC_DROP_FRAME = 8,
+        FrameRate_NTSC_FULL_FRAME = 9,
+        FrameRate_PAL = 10,
+        FrameRate_CINEMA = 11,
+        FrameRate_1000 = 12,
+        FrameRate_CINEMA_ND = 13,
+        FrameRate_CUSTOM = 14,
+
+        FrameRate_MAX// end-of-enum sentinel
+    };
+
+    fbx_simple_enum_property(TimeMode, FrameRate, FrameRate_DEFAULT)
+    fbx_simple_property(TimeSpanStart, uint64_t, 0L)
+    fbx_simple_property(TimeSpanStop, uint64_t, 0L)
+    fbx_simple_property(CustomFrameRate, float, -1.0f)
+
+private:
+    std::shared_ptr<const PropertyTable> props;
+    const Document& doc;
+};
+
+/** DOM root for a FBX file */
+class Document {
+public:
+    Document(const Parser& parser, const ImportSettings& settings);
+
+    ~Document();
+
+    LazyObject* GetObject(uint64_t id) const;
+
+    bool IsBinary() const {
+        return parser.IsBinary();
+    }
+
+    unsigned int FBXVersion() const {
+        return fbxVersion;
+    }
+
+    const std::string& Creator() const {
+        return creator;
+    }
+
+    // elements (in this order): Year, Month, Day, Hour, Second, Millisecond
+    const unsigned int* CreationTimeStamp() const {
+        return creationTimeStamp;
+    }
+
+    const FileGlobalSettings& GlobalSettings() const {
+        ai_assert(globals.get());
+        return *globals.get();
+    }
+
+    const PropertyTemplateMap& Templates() const {
+        return templates;
+    }
+
+    const ObjectMap& Objects() const {
+        return objects;
+    }
+
+    const ImportSettings& Settings() const {
+        return settings;
+    }
+
+    const ConnectionMap& ConnectionsBySource() const {
+        return src_connections;
+    }
+
+    const ConnectionMap& ConnectionsByDestination() const {
+        return dest_connections;
+    }
+
+    // note: the implicit rule in all DOM classes is to always resolve
+    // from destination to source (since the FBX object hierarchy is,
+    // with very few exceptions, a DAG, this avoids cycles). In all
+    // cases that may involve back-facing edges in the object graph,
+    // use LazyObject::IsBeingConstructed() to check.
+
+    std::vector<const Connection*> GetConnectionsBySourceSequenced(uint64_t source) const;
+    std::vector<const Connection*> GetConnectionsByDestinationSequenced(uint64_t dest) const;
+
+    std::vector<const Connection*> GetConnectionsBySourceSequenced(uint64_t source, const char* classname) const;
+    std::vector<const Connection*> GetConnectionsByDestinationSequenced(uint64_t dest, const char* classname) const;
+
+    std::vector<const Connection*> GetConnectionsBySourceSequenced(uint64_t source,
+        const char* const* classnames, size_t count) const;
+    std::vector<const Connection*> GetConnectionsByDestinationSequenced(uint64_t dest,
+        const char* const* classnames,
+        size_t count) const;
+
+    const std::vector<const AnimationStack*>& AnimationStacks() const;
+
+private:
+    std::vector<const Connection*> GetConnectionsSequenced(uint64_t id, const ConnectionMap&) const;
+    std::vector<const Connection*> GetConnectionsSequenced(uint64_t id, bool is_src,
+        const ConnectionMap&,
+        const char* const* classnames,
+        size_t count) const;
+    void ReadHeader();
+    void ReadObjects();
+    void ReadPropertyTemplates();
+    void ReadConnections();
+    void ReadGlobalSettings();
+
+private:
+    const ImportSettings& settings;
+
+    ObjectMap objects;
+    const Parser& parser;
+
+    PropertyTemplateMap templates;
+    ConnectionMap src_connections;
+    ConnectionMap dest_connections;
+
+    unsigned int fbxVersion;
+    std::string creator;
+    unsigned int creationTimeStamp[7];
+
+    std::vector<uint64_t> animationStacks;
+    mutable std::vector<const AnimationStack*> animationStacksResolved;
+
+    std::unique_ptr<FileGlobalSettings> globals;
+};
+
+} // Namespace FBX
+} // Namespace Assimp
+
+#endif // INCLUDED_AI_FBX_DOCUMENT_H
diff --git a/thirdparty/assimp/code/FBX/FBXDocumentUtil.cpp b/thirdparty/assimp/code/FBX/FBXDocumentUtil.cpp
new file mode 100644
index 0000000000..f84691479a
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXDocumentUtil.cpp
@@ -0,0 +1,135 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXDocumentUtil.cpp
+ *  @brief Implementation of the FBX DOM utility functions declared in FBXDocumentUtil.h
+ */
+
+#ifndef ASSIMP_BUILD_NO_FBX_IMPORTER
+
+#include "FBXParser.h"
+#include "FBXDocument.h"
+#include "FBXUtil.h"
+#include "FBXDocumentUtil.h"
+#include "FBXProperties.h"
+
+
+namespace Assimp {
+namespace FBX {
+namespace Util {
+
+// ------------------------------------------------------------------------------------------------
+// signal DOM construction error, this is always unrecoverable. Throws DeadlyImportError.
+void DOMError(const std::string& message, const Token& token)
+{
+    throw DeadlyImportError(Util::AddTokenText("FBX-DOM",message,&token));
+}
+
+// ------------------------------------------------------------------------------------------------
+void DOMError(const std::string& message, const Element* element /*= NULL*/)
+{
+    if(element) {
+        DOMError(message,element->KeyToken());
+    }
+    throw DeadlyImportError("FBX-DOM " + message);
+}
+
+
+// ------------------------------------------------------------------------------------------------
+// print warning, do return
+void DOMWarning(const std::string& message, const Token& token)
+{
+    if(DefaultLogger::get()) {
+        ASSIMP_LOG_WARN(Util::AddTokenText("FBX-DOM",message,&token));
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+void DOMWarning(const std::string& message, const Element* element /*= NULL*/)
+{
+    if(element) {
+        DOMWarning(message,element->KeyToken());
+        return;
+    }
+    if(DefaultLogger::get()) {
+        ASSIMP_LOG_WARN("FBX-DOM: " + message);
+    }
+}
+
+
+// ------------------------------------------------------------------------------------------------
+// fetch a property table and the corresponding property template
+std::shared_ptr<const PropertyTable> GetPropertyTable(const Document& doc,
+    const std::string& templateName,
+    const Element &element,
+    const Scope& sc,
+    bool no_warn /*= false*/)
+{
+    const Element* const Properties70 = sc["Properties70"];
+    std::shared_ptr<const PropertyTable> templateProps = std::shared_ptr<const PropertyTable>(
+        static_cast<const PropertyTable*>(NULL));
+
+    if(templateName.length()) {
+        PropertyTemplateMap::const_iterator it = doc.Templates().find(templateName);
+        if(it != doc.Templates().end()) {
+            templateProps = (*it).second;
+        }
+    }
+
+    if(!Properties70 || !Properties70->Compound()) {
+        if(!no_warn) {
+            DOMWarning("property table (Properties70) not found",&element);
+        }
+        if(templateProps) {
+            return templateProps;
+        }
+        else {
+            return std::make_shared<const PropertyTable>();
+        }
+    }
+    return std::make_shared<const PropertyTable>(*Properties70,templateProps);
+}
+} // !Util
+} // !FBX
+} // !Assimp
+
+#endif
diff --git a/thirdparty/assimp/code/FBX/FBXDocumentUtil.h b/thirdparty/assimp/code/FBX/FBXDocumentUtil.h
new file mode 100644
index 0000000000..2450109e59
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXDocumentUtil.h
@@ -0,0 +1,120 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2012, assimp team
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXDocumentUtil.h
+ *  @brief FBX internal utilities used by the DOM reading code
+ */
+#ifndef INCLUDED_AI_FBX_DOCUMENT_UTIL_H
+#define INCLUDED_AI_FBX_DOCUMENT_UTIL_H
+
+#include <assimp/defs.h>
+#include <string>
+#include <memory>
+#include "FBXDocument.h"
+
+struct Token;
+struct Element;
+
+namespace Assimp {
+namespace FBX {
+namespace Util {
+
+/* DOM/Parse error reporting - does not return */
+AI_WONT_RETURN void DOMError(const std::string& message, const Token& token) AI_WONT_RETURN_SUFFIX;
+AI_WONT_RETURN void DOMError(const std::string& message, const Element* element = NULL) AI_WONT_RETURN_SUFFIX;
+
+// does return
+void DOMWarning(const std::string& message, const Token& token);
+void DOMWarning(const std::string& message, const Element* element = NULL);
+
+
+// fetch a property table and the corresponding property template
+std::shared_ptr<const PropertyTable> GetPropertyTable(const Document& doc,
+    const std::string& templateName,
+    const Element &element,
+    const Scope& sc,
+    bool no_warn = false);
+
+// ------------------------------------------------------------------------------------------------
+template <typename T>
+inline
+const T* ProcessSimpleConnection(const Connection& con,
+    bool is_object_property_conn,
+    const char* name,
+    const Element& element,
+    const char** propNameOut = nullptr)
+{
+    if (is_object_property_conn && !con.PropertyName().length()) {
+        DOMWarning("expected incoming " + std::string(name) +
+            " link to be an object-object connection, ignoring",
+            &element
+            );
+        return nullptr;
+    }
+    else if (!is_object_property_conn && con.PropertyName().length()) {
+        DOMWarning("expected incoming " + std::string(name) +
+            " link to be an object-property connection, ignoring",
+            &element
+            );
+        return nullptr;
+    }
+
+    if(is_object_property_conn && propNameOut) {
+        // note: this is ok, the return value of PropertyValue() is guaranteed to
+        // remain valid and unchanged as long as the document exists.
+        *propNameOut = con.PropertyName().c_str();
+    }
+
+    const Object* const ob = con.SourceObject();
+    if(!ob) {
+        DOMWarning("failed to read source object for incoming " + std::string(name) +
+            " link, ignoring",
+            &element);
+        return nullptr;
+    }
+
+    return dynamic_cast<const T*>(ob);
+}
+
+} //!Util
+} //!FBX
+} //!Assimp
+
+#endif
diff --git a/thirdparty/assimp/code/FBX/FBXExportNode.cpp b/thirdparty/assimp/code/FBX/FBXExportNode.cpp
new file mode 100644
index 0000000000..06c89cee46
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXExportNode.cpp
@@ -0,0 +1,571 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+copyright notice, this list of conditions and the
+following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other
+materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+contributors may be used to endorse or promote products
+derived from this software without specific prior
+written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+#ifndef ASSIMP_BUILD_NO_EXPORT
+#ifndef ASSIMP_BUILD_NO_FBX_EXPORTER
+
+#include "FBXExportNode.h"
+#include "FBXCommon.h"
+
+#include <assimp/StreamWriter.h> // StreamWriterLE
+#include <assimp/Exceptional.h> // DeadlyExportError
+#include <assimp/ai_assert.h>
+#include <assimp/StringUtils.h> // ai_snprintf
+
+#include <string>
+#include <ostream>
+#include <sstream> // ostringstream
+#include <memory> // shared_ptr
+
+namespace Assimp {
+// AddP70<type> helpers... there's no usable pattern here,
+// so all are defined as separate functions.
+// Even "animatable" properties are often completely different
+// from the standard (nonanimated) property definition,
+// so they are specified with an 'A' suffix.
+
+void FBX::Node::AddP70int(
+    const std::string& name, int32_t value
+) {
+    FBX::Node n("P");
+    n.AddProperties(name, "int", "Integer", "", value);
+    AddChild(n);
+}
+
+void FBX::Node::AddP70bool(
+    const std::string& name, bool value
+) {
+    FBX::Node n("P");
+    n.AddProperties(name, "bool", "", "", int32_t(value));
+    AddChild(n);
+}
+
+void FBX::Node::AddP70double(
+    const std::string& name, double value
+) {
+    FBX::Node n("P");
+    n.AddProperties(name, "double", "Number", "", value);
+    AddChild(n);
+}
+
+void FBX::Node::AddP70numberA(
+    const std::string& name, double value
+) {
+    FBX::Node n("P");
+    n.AddProperties(name, "Number", "", "A", value);
+    AddChild(n);
+}
+
+void FBX::Node::AddP70color(
+    const std::string& name, double r, double g, double b
+) {
+    FBX::Node n("P");
+    n.AddProperties(name, "ColorRGB", "Color", "", r, g, b);
+    AddChild(n);
+}
+
+void FBX::Node::AddP70colorA(
+    const std::string& name, double r, double g, double b
+) {
+    FBX::Node n("P");
+    n.AddProperties(name, "Color", "", "A", r, g, b);
+    AddChild(n);
+}
+
+void FBX::Node::AddP70vector(
+    const std::string& name, double x, double y, double z
+) {
+    FBX::Node n("P");
+    n.AddProperties(name, "Vector3D", "Vector", "", x, y, z);
+    AddChild(n);
+}
+
+void FBX::Node::AddP70vectorA(
+    const std::string& name, double x, double y, double z
+) {
+    FBX::Node n("P");
+    n.AddProperties(name, "Vector", "", "A", x, y, z);
+    AddChild(n);
+}
+
+void FBX::Node::AddP70string(
+    const std::string& name, const std::string& value
+) {
+    FBX::Node n("P");
+    n.AddProperties(name, "KString", "", "", value);
+    AddChild(n);
+}
+
+void FBX::Node::AddP70enum(
+    const std::string& name, int32_t value
+) {
+    FBX::Node n("P");
+    n.AddProperties(name, "enum", "", "", value);
+    AddChild(n);
+}
+
+void FBX::Node::AddP70time(
+    const std::string& name, int64_t value
+) {
+    FBX::Node n("P");
+    n.AddProperties(name, "KTime", "Time", "", value);
+    AddChild(n);
+}
+
+
+// public member functions for writing nodes to stream
+
+void FBX::Node::Dump(
+    std::shared_ptr<Assimp::IOStream> outfile,
+    bool binary, int indent
+) {
+    if (binary) {
+        Assimp::StreamWriterLE outstream(outfile);
+        DumpBinary(outstream);
+    } else {
+        std::ostringstream ss;
+        DumpAscii(ss, indent);
+        std::string s = ss.str();
+        outfile->Write(s.c_str(), s.size(), 1);
+    }
+}
+
+void FBX::Node::Dump(
+    Assimp::StreamWriterLE &outstream,
+    bool binary, int indent
+) {
+    if (binary) {
+        DumpBinary(outstream);
+    } else {
+        std::ostringstream ss;
+        DumpAscii(ss, indent);
+        outstream.PutString(ss.str());
+    }
+}
+
+
+// public member functions for low-level writing
+
+void FBX::Node::Begin(
+    Assimp::StreamWriterLE &s,
+    bool binary, int indent
+) {
+    if (binary) {
+        BeginBinary(s);
+    } else {
+        // assume we're at the correct place to start already
+        (void)indent;
+        std::ostringstream ss;
+        BeginAscii(ss, indent);
+        s.PutString(ss.str());
+    }
+}
+
+void FBX::Node::DumpProperties(
+    Assimp::StreamWriterLE& s,
+    bool binary, int indent
+) {
+    if (binary) {
+        DumpPropertiesBinary(s);
+    } else {
+        std::ostringstream ss;
+        DumpPropertiesAscii(ss, indent);
+        s.PutString(ss.str());
+    }
+}
+
+void FBX::Node::EndProperties(
+    Assimp::StreamWriterLE &s,
+    bool binary, int indent
+) {
+    EndProperties(s, binary, indent, properties.size());
+}
+
+void FBX::Node::EndProperties(
+    Assimp::StreamWriterLE &s,
+    bool binary, int indent,
+    size_t num_properties
+) {
+    if (binary) {
+        EndPropertiesBinary(s, num_properties);
+    } else {
+        // nothing to do
+        (void)indent;
+    }
+}
+
+void FBX::Node::BeginChildren(
+    Assimp::StreamWriterLE &s,
+    bool binary, int indent
+) {
+    if (binary) {
+        // nothing to do
+    } else {
+        std::ostringstream ss;
+        BeginChildrenAscii(ss, indent);
+        s.PutString(ss.str());
+    }
+}
+
+void FBX::Node::DumpChildren(
+    Assimp::StreamWriterLE& s,
+    bool binary, int indent
+) {
+    if (binary) {
+        DumpChildrenBinary(s);
+    } else {
+        std::ostringstream ss;
+        DumpChildrenAscii(ss, indent);
+        if (ss.tellp() > 0)
+            s.PutString(ss.str());
+    }
+}
+
+void FBX::Node::End(
+    Assimp::StreamWriterLE &s,
+    bool binary, int indent,
+    bool has_children
+) {
+    if (binary) {
+        EndBinary(s, has_children);
+    } else {
+        std::ostringstream ss;
+        EndAscii(ss, indent, has_children);
+        if (ss.tellp() > 0)
+            s.PutString(ss.str());
+    }
+}
+
+
+// public member functions for writing to binary fbx
+
+void FBX::Node::DumpBinary(Assimp::StreamWriterLE &s)
+{
+    // write header section (with placeholders for some things)
+    BeginBinary(s);
+
+    // write properties
+    DumpPropertiesBinary(s);
+
+    // go back and fill in property related placeholders
+    EndPropertiesBinary(s, properties.size());
+
+    // write children
+    DumpChildrenBinary(s);
+
+    // finish, filling in end offset placeholder
+    EndBinary(s, force_has_children || !children.empty());
+}
+
+
+// public member functions for writing to ascii fbx
+
+void FBX::Node::DumpAscii(std::ostream &s, int indent)
+{
+    // write name
+    BeginAscii(s, indent);
+
+    // write properties
+    DumpPropertiesAscii(s, indent);
+
+    if (force_has_children || !children.empty()) {
+        // begin children (with a '{')
+        BeginChildrenAscii(s, indent + 1);
+        // write children
+        DumpChildrenAscii(s, indent + 1);
+    }
+
+    // finish (also closing the children bracket '}')
+    EndAscii(s, indent, force_has_children || !children.empty());
+}
+
+
+// private member functions for low-level writing to fbx
+
+void FBX::Node::BeginBinary(Assimp::StreamWriterLE &s)
+{
+    // remember start pos so we can come back and write the end pos
+    this->start_pos = s.Tell();
+
+    // placeholders for end pos and property section info
+    s.PutU4(0); // end pos
+    s.PutU4(0); // number of properties
+    s.PutU4(0); // total property section length
+
+    // node name
+    s.PutU1(uint8_t(name.size())); // length of node name
+    s.PutString(name); // node name as raw bytes
+
+    // property data comes after here
+    this->property_start = s.Tell();
+}
+
+void FBX::Node::DumpPropertiesBinary(Assimp::StreamWriterLE& s)
+{
+    for (auto &p : properties) {
+        p.DumpBinary(s);
+    }
+}
+
+void FBX::Node::EndPropertiesBinary(
+    Assimp::StreamWriterLE &s,
+    size_t num_properties
+) {
+    if (num_properties == 0) { return; }
+    size_t pos = s.Tell();
+    ai_assert(pos > property_start);
+    size_t property_section_size = pos - property_start;
+    s.Seek(start_pos + 4);
+    s.PutU4(uint32_t(num_properties));
+    s.PutU4(uint32_t(property_section_size));
+    s.Seek(pos);
+}
+
+void FBX::Node::DumpChildrenBinary(Assimp::StreamWriterLE& s)
+{
+    for (FBX::Node& child : children) {
+        child.DumpBinary(s);
+    }
+}
+
+void FBX::Node::EndBinary(
+    Assimp::StreamWriterLE &s,
+    bool has_children
+) {
+    // if there were children, add a null record
+    if (has_children) { s.PutString(Assimp::FBX::NULL_RECORD); }
+
+    // now go back and write initial pos
+    this->end_pos = s.Tell();
+    s.Seek(start_pos);
+    s.PutU4(uint32_t(end_pos));
+    s.Seek(end_pos);
+}
+
+
+void FBX::Node::BeginAscii(std::ostream& s, int indent)
+{
+    s << '\n';
+    for (int i = 0; i < indent; ++i) { s << '\t'; }
+    s << name << ": ";
+}
+
+void FBX::Node::DumpPropertiesAscii(std::ostream &s, int indent)
+{
+    for (size_t i = 0; i < properties.size(); ++i) {
+        if (i > 0) { s << ", "; }
+        properties[i].DumpAscii(s, indent);
+    }
+}
+
+void FBX::Node::BeginChildrenAscii(std::ostream& s, int indent)
+{
+    // only call this if there are actually children
+    s << " {";
+    (void)indent;
+}
+
+void FBX::Node::DumpChildrenAscii(std::ostream& s, int indent)
+{
+    // children will need a lot of padding and corralling
+    if (children.size() || force_has_children) {
+        for (size_t i = 0; i < children.size(); ++i) {
+            // no compression in ascii files, so skip this node if it exists
+            if (children[i].name == "EncryptionType") { continue; }
+            // the child can dump itself
+            children[i].DumpAscii(s, indent);
+        }
+    }
+}
+
+void FBX::Node::EndAscii(std::ostream& s, int indent, bool has_children)
+{
+    if (!has_children) { return; } // nothing to do
+    s << '\n';
+    for (int i = 0; i < indent; ++i) { s << '\t'; }
+    s << "}";
+}
+
+// private helpers for static member functions
+
+// ascii property node from vector of doubles
+void FBX::Node::WritePropertyNodeAscii(
+    const std::string& name,
+    const std::vector<double>& v,
+    Assimp::StreamWriterLE& s,
+    int indent
+){
+    char buffer[32];
+    FBX::Node node(name);
+    node.Begin(s, false, indent);
+    std::string vsize = to_string(v.size());
+    // *<size> {
+    s.PutChar('*'); s.PutString(vsize); s.PutString(" {\n");
+    // indent + 1
+    for (int i = 0; i < indent + 1; ++i) { s.PutChar('\t'); }
+    // a: value,value,value,...
+    s.PutString("a: ");
+    int count = 0;
+    for (size_t i = 0; i < v.size(); ++i) {
+        if (i > 0) { s.PutChar(','); }
+        int len = ai_snprintf(buffer, sizeof(buffer), "%f", v[i]);
+        count += len;
+        if (count > 2048) { s.PutChar('\n'); count = 0; }
+        if (len < 0 || len > 31) {
+            // this should never happen
+            throw DeadlyExportError("failed to convert double to string");
+        }
+        for (int j = 0; j < len; ++j) { s.PutChar(buffer[j]); }
+    }
+    // }
+    s.PutChar('\n');
+    for (int i = 0; i < indent; ++i) { s.PutChar('\t'); }
+    s.PutChar('}'); s.PutChar(' ');
+    node.End(s, false, indent, false);
+}
+
+// ascii property node from vector of int32_t
+void FBX::Node::WritePropertyNodeAscii(
+    const std::string& name,
+    const std::vector<int32_t>& v,
+    Assimp::StreamWriterLE& s,
+    int indent
+){
+    char buffer[32];
+    FBX::Node node(name);
+    node.Begin(s, false, indent);
+    std::string vsize = to_string(v.size());
+    // *<size> {
+    s.PutChar('*'); s.PutString(vsize); s.PutString(" {\n");
+    // indent + 1
+    for (int i = 0; i < indent + 1; ++i) { s.PutChar('\t'); }
+    // a: value,value,value,...
+    s.PutString("a: ");
+    int count = 0;
+    for (size_t i = 0; i < v.size(); ++i) {
+        if (i > 0) { s.PutChar(','); }
+        int len = ai_snprintf(buffer, sizeof(buffer), "%d", v[i]);
+        count += len;
+        if (count > 2048) { s.PutChar('\n'); count = 0; }
+        if (len < 0 || len > 31) {
+            // this should never happen
+            throw DeadlyExportError("failed to convert double to string");
+        }
+        for (int j = 0; j < len; ++j) { s.PutChar(buffer[j]); }
+    }
+    // }
+    s.PutChar('\n');
+    for (int i = 0; i < indent; ++i) { s.PutChar('\t'); }
+    s.PutChar('}'); s.PutChar(' ');
+    node.End(s, false, indent, false);
+}
+
+// binary property node from vector of doubles
+// TODO: optional zip compression!
+void FBX::Node::WritePropertyNodeBinary(
+    const std::string& name,
+    const std::vector<double>& v,
+    Assimp::StreamWriterLE& s
+){
+    FBX::Node node(name);
+    node.BeginBinary(s);
+    s.PutU1('d');
+    s.PutU4(uint32_t(v.size())); // number of elements
+    s.PutU4(0); // no encoding (1 would be zip-compressed)
+    s.PutU4(uint32_t(v.size()) * 8); // data size
+    for (auto it = v.begin(); it != v.end(); ++it) { s.PutF8(*it); }
+    node.EndPropertiesBinary(s, 1);
+    node.EndBinary(s, false);
+}
+
+// binary property node from vector of int32_t
+// TODO: optional zip compression!
+void FBX::Node::WritePropertyNodeBinary(
+    const std::string& name,
+    const std::vector<int32_t>& v,
+    Assimp::StreamWriterLE& s
+){
+    FBX::Node node(name);
+    node.BeginBinary(s);
+    s.PutU1('i');
+    s.PutU4(uint32_t(v.size())); // number of elements
+    s.PutU4(0); // no encoding (1 would be zip-compressed)
+    s.PutU4(uint32_t(v.size()) * 4); // data size
+    for (auto it = v.begin(); it != v.end(); ++it) { s.PutI4(*it); }
+    node.EndPropertiesBinary(s, 1);
+    node.EndBinary(s, false);
+}
+
+// public static member functions
+
+// convenience function to create and write a property node,
+// holding a single property which is an array of values.
+// does not copy the data, so is efficient for large arrays.
+void FBX::Node::WritePropertyNode(
+    const std::string& name,
+    const std::vector<double>& v,
+    Assimp::StreamWriterLE& s,
+    bool binary, int indent
+){
+    if (binary) {
+        FBX::Node::WritePropertyNodeBinary(name, v, s);
+    } else {
+        FBX::Node::WritePropertyNodeAscii(name, v, s, indent);
+    }
+}
+
+// convenience function to create and write a property node,
+// holding a single property which is an array of values.
+// does not copy the data, so is efficient for large arrays.
+void FBX::Node::WritePropertyNode(
+    const std::string& name,
+    const std::vector<int32_t>& v,
+    Assimp::StreamWriterLE& s,
+    bool binary, int indent
+){
+    if (binary) {
+        FBX::Node::WritePropertyNodeBinary(name, v, s);
+    } else {
+        FBX::Node::WritePropertyNodeAscii(name, v, s, indent);
+    }
+}
+}
+#endif // ASSIMP_BUILD_NO_FBX_EXPORTER
+#endif // ASSIMP_BUILD_NO_EXPORT
diff --git a/thirdparty/assimp/code/FBX/FBXExportNode.h b/thirdparty/assimp/code/FBX/FBXExportNode.h
new file mode 100644
index 0000000000..ef3bc781a4
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXExportNode.h
@@ -0,0 +1,271 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+copyright notice, this list of conditions and the
+following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other
+materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+contributors may be used to endorse or promote products
+derived from this software without specific prior
+written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file FBXExportNode.h
+* Declares the FBX::Node helper class for fbx export.
+*/
+#ifndef AI_FBXEXPORTNODE_H_INC
+#define AI_FBXEXPORTNODE_H_INC
+
+#ifndef ASSIMP_BUILD_NO_FBX_EXPORTER
+
+#include "FBXExportProperty.h"
+
+#include <assimp/StreamWriter.h> // StreamWriterLE
+
+#include <string>
+#include <vector>
+
+namespace Assimp {
+namespace FBX {
+    class Node;
+}
+
+class FBX::Node {
+public: 
+    // TODO: accessors
+    std::string name; // node name
+    std::vector<FBX::FBXExportProperty> properties; // node properties
+    std::vector<FBX::Node> children; // child nodes
+
+    // some nodes always pretend they have children...
+    bool force_has_children = false;
+
+public: // constructors
+    /// The default class constructor.
+    Node() = default;
+
+    /// The class constructor with the name.
+    Node(const std::string& n)
+    : name(n)
+    , properties()
+    , children()
+    , force_has_children( false ) {
+        // empty
+    }
+
+    // convenience template to construct with properties directly
+    template <typename... More>
+    Node(const std::string& n, const More... more)
+    : name(n)
+    , properties()
+    , children()
+    , force_has_children(false) {
+        AddProperties(more...);
+    }
+
+public: // functions to add properties or children
+    // add a single property to the node
+    template <typename T>
+    void AddProperty(T value) {
+        properties.emplace_back(value);
+    }
+
+    // convenience function to add multiple properties at once
+    template <typename T, typename... More>
+    void AddProperties(T value, More... more) {
+        properties.emplace_back(value);
+        AddProperties(more...);
+    }
+    void AddProperties() {}
+
+    // add a child node directly
+    void AddChild(const Node& node) { children.push_back(node); }
+
+    // convenience function to add a child node with a single property
+    template <typename... More>
+    void AddChild(
+        const std::string& name,
+        More... more
+    ) {
+        FBX::Node c(name);
+        c.AddProperties(more...);
+        children.push_back(c);
+    }
+
+public: // support specifically for dealing with Properties70 nodes
+
+    // it really is simpler to make these all separate functions.
+    // the versions with 'A' suffixes are for animatable properties.
+    // those often follow a completely different format internally in FBX.
+    void AddP70int(const std::string& name, int32_t value);
+    void AddP70bool(const std::string& name, bool value);
+    void AddP70double(const std::string& name, double value);
+    void AddP70numberA(const std::string& name, double value);
+    void AddP70color(const std::string& name, double r, double g, double b);
+    void AddP70colorA(const std::string& name, double r, double g, double b);
+    void AddP70vector(const std::string& name, double x, double y, double z);
+    void AddP70vectorA(const std::string& name, double x, double y, double z);
+    void AddP70string(const std::string& name, const std::string& value);
+    void AddP70enum(const std::string& name, int32_t value);
+    void AddP70time(const std::string& name, int64_t value);
+
+    // template for custom P70 nodes.
+    // anything that doesn't fit in the above can be created manually.
+    template <typename... More>
+    void AddP70(
+        const std::string& name,
+        const std::string& type,
+        const std::string& type2,
+        const std::string& flags,
+        More... more
+    ) {
+        Node n("P");
+        n.AddProperties(name, type, type2, flags, more...);
+        AddChild(n);
+    }
+
+public: // member functions for writing data to a file or stream
+
+    // write the full node to the given file or stream
+    void Dump(
+        std::shared_ptr<Assimp::IOStream> outfile,
+        bool binary, int indent
+    );
+    void Dump(Assimp::StreamWriterLE &s, bool binary, int indent);
+
+    // these other functions are for writing data piece by piece.
+    // they must be used carefully.
+    // for usage examples see FBXExporter.cpp.
+    void Begin(Assimp::StreamWriterLE &s, bool binary, int indent);
+    void DumpProperties(Assimp::StreamWriterLE& s, bool binary, int indent);
+    void EndProperties(Assimp::StreamWriterLE &s, bool binary, int indent);
+    void EndProperties(
+        Assimp::StreamWriterLE &s, bool binary, int indent,
+        size_t num_properties
+    );
+    void BeginChildren(Assimp::StreamWriterLE &s, bool binary, int indent);
+    void DumpChildren(Assimp::StreamWriterLE& s, bool binary, int indent);
+    void End(
+        Assimp::StreamWriterLE &s, bool binary, int indent,
+        bool has_children
+    );
+
+private: // internal functions used for writing
+
+    void DumpBinary(Assimp::StreamWriterLE &s);
+    void DumpAscii(Assimp::StreamWriterLE &s, int indent);
+    void DumpAscii(std::ostream &s, int indent);
+
+    void BeginBinary(Assimp::StreamWriterLE &s);
+    void DumpPropertiesBinary(Assimp::StreamWriterLE& s);
+    void EndPropertiesBinary(Assimp::StreamWriterLE &s);
+    void EndPropertiesBinary(Assimp::StreamWriterLE &s, size_t num_properties);
+    void DumpChildrenBinary(Assimp::StreamWriterLE& s);
+    void EndBinary(Assimp::StreamWriterLE &s, bool has_children);
+
+    void BeginAscii(std::ostream &s, int indent);
+    void DumpPropertiesAscii(std::ostream &s, int indent);
+    void BeginChildrenAscii(std::ostream &s, int indent);
+    void DumpChildrenAscii(std::ostream &s, int indent);
+    void EndAscii(std::ostream &s, int indent, bool has_children);
+
+private: // data used for binary dumps
+    size_t start_pos; // starting position in stream
+    size_t end_pos; // ending position in stream
+    size_t property_start; // starting position of property section
+
+public: // static member functions
+
+    // convenience function to create a node with a single property,
+    // and write it to the stream.
+    template <typename T>
+    static void WritePropertyNode(
+        const std::string& name,
+        const T value,
+        Assimp::StreamWriterLE& s,
+        bool binary, int indent
+    ) {
+        FBX::FBXExportProperty p(value);
+        FBX::Node node(name, p);
+        node.Dump(s, binary, indent);
+    }
+
+    // convenience function to create and write a property node,
+    // holding a single property which is an array of values.
+    // does not copy the data, so is efficient for large arrays.
+    static void WritePropertyNode(
+        const std::string& name,
+        const std::vector<double>& v,
+        Assimp::StreamWriterLE& s,
+        bool binary, int indent
+    );
+
+    // convenience function to create and write a property node,
+    // holding a single property which is an array of values.
+    // does not copy the data, so is efficient for large arrays.
+    static void WritePropertyNode(
+        const std::string& name,
+        const std::vector<int32_t>& v,
+        Assimp::StreamWriterLE& s,
+        bool binary, int indent
+    );
+
+private: // static helper functions
+    static void WritePropertyNodeAscii(
+        const std::string& name,
+        const std::vector<double>& v,
+        Assimp::StreamWriterLE& s,
+        int indent
+    );
+    static void WritePropertyNodeAscii(
+        const std::string& name,
+        const std::vector<int32_t>& v,
+        Assimp::StreamWriterLE& s,
+        int indent
+    );
+    static void WritePropertyNodeBinary(
+        const std::string& name,
+        const std::vector<double>& v,
+        Assimp::StreamWriterLE& s
+    );
+    static void WritePropertyNodeBinary(
+        const std::string& name,
+        const std::vector<int32_t>& v,
+        Assimp::StreamWriterLE& s
+    );
+
+};
+}
+
+#endif // ASSIMP_BUILD_NO_FBX_EXPORTER
+
+#endif // AI_FBXEXPORTNODE_H_INC
diff --git a/thirdparty/assimp/code/FBX/FBXExportProperty.cpp b/thirdparty/assimp/code/FBX/FBXExportProperty.cpp
new file mode 100644
index 0000000000..f8593e6295
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXExportProperty.cpp
@@ -0,0 +1,389 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+copyright notice, this list of conditions and the
+following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other
+materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+contributors may be used to endorse or promote products
+derived from this software without specific prior
+written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+#ifndef ASSIMP_BUILD_NO_EXPORT
+#ifndef ASSIMP_BUILD_NO_FBX_EXPORTER
+
+#include "FBXExportProperty.h"
+
+#include <assimp/StreamWriter.h> // StreamWriterLE
+#include <assimp/Exceptional.h> // DeadlyExportError
+
+#include <string>
+#include <vector>
+#include <ostream>
+#include <locale>
+#include <sstream> // ostringstream
+
+namespace Assimp {
+namespace FBX {
+
+// constructors for single element properties
+
+FBXExportProperty::FBXExportProperty(bool v)
+: type('C')
+, data(1) {
+    data = {
+        uint8_t(v)
+    };
+}
+
+FBXExportProperty::FBXExportProperty(int16_t v)
+: type('Y')
+, data(2) {
+    uint8_t* d = data.data();
+    (reinterpret_cast<int16_t*>(d))[0] = v;
+}
+
+FBXExportProperty::FBXExportProperty(int32_t v)
+: type('I')
+, data(4) {
+    uint8_t* d = data.data();
+    (reinterpret_cast<int32_t*>(d))[0] = v;
+}
+
+FBXExportProperty::FBXExportProperty(float v)
+: type('F')
+, data(4) {
+    uint8_t* d = data.data();
+    (reinterpret_cast<float*>(d))[0] = v;
+}
+
+FBXExportProperty::FBXExportProperty(double v)
+: type('D')
+, data(8) {
+    uint8_t* d = data.data();
+    (reinterpret_cast<double*>(d))[0] = v;
+}
+
+FBXExportProperty::FBXExportProperty(int64_t v)
+: type('L')
+, data(8) {
+    uint8_t* d = data.data();
+    (reinterpret_cast<int64_t*>(d))[0] = v;
+}
+
+// constructors for array-type properties
+
+FBXExportProperty::FBXExportProperty(const char* c, bool raw)
+: FBXExportProperty(std::string(c), raw) {
+    // empty
+}
+
+// strings can either be saved as "raw" (R) data, or "string" (S) data
+FBXExportProperty::FBXExportProperty(const std::string& s, bool raw)
+: type(raw ? 'R' : 'S')
+, data(s.size()) {
+    for (size_t i = 0; i < s.size(); ++i) {
+        data[i] = uint8_t(s[i]);
+    }
+}
+
+FBXExportProperty::FBXExportProperty(const std::vector<uint8_t>& r)
+: type('R')
+, data(r) {
+    // empty
+}
+
+FBXExportProperty::FBXExportProperty(const std::vector<int32_t>& va)
+: type('i')
+, data(4 * va.size() ) {
+    int32_t* d = reinterpret_cast<int32_t*>(data.data());
+    for (size_t i = 0; i < va.size(); ++i) {
+        d[i] = va[i];
+    }
+}
+
+FBXExportProperty::FBXExportProperty(const std::vector<int64_t>& va)
+: type('l')
+, data(8 * va.size()) {
+    int64_t* d = reinterpret_cast<int64_t*>(data.data());
+    for (size_t i = 0; i < va.size(); ++i) {
+        d[i] = va[i];
+    }
+}
+
+FBXExportProperty::FBXExportProperty(const std::vector<float>& va)
+: type('f')
+, data(4 * va.size()) {
+    float* d = reinterpret_cast<float*>(data.data());
+    for (size_t i = 0; i < va.size(); ++i) {
+        d[i] = va[i];
+    }
+}
+
+FBXExportProperty::FBXExportProperty(const std::vector<double>& va)
+: type('d')
+, data(8 * va.size()) {
+    double* d = reinterpret_cast<double*>(data.data());
+    for (size_t i = 0; i < va.size(); ++i) {
+        d[i] = va[i];
+    }
+}
+
+FBXExportProperty::FBXExportProperty(const aiMatrix4x4& vm)
+: type('d')
+, data(8 * 16) {
+    double* d = reinterpret_cast<double*>(data.data());
+    for (unsigned int c = 0; c < 4; ++c) {
+        for (unsigned int r = 0; r < 4; ++r) {
+            d[4 * c + r] = vm[r][c];
+        }
+    }
+}
+
+// public member functions
+
+size_t FBXExportProperty::size() {
+    switch (type) {
+        case 'C':
+        case 'Y':
+        case 'I':
+        case 'F':
+        case 'D':
+        case 'L':
+            return data.size() + 1;
+        case 'S':
+        case 'R':
+            return data.size() + 5;
+        case 'i':
+        case 'd':
+            return data.size() + 13;
+        default:
+            throw DeadlyExportError("Requested size on property of unknown type");
+    }
+}
+
+void FBXExportProperty::DumpBinary(Assimp::StreamWriterLE& s) {
+    s.PutU1(type);
+    uint8_t* d = data.data();
+    size_t N;
+    switch (type) {
+        case 'C': s.PutU1(*(reinterpret_cast<uint8_t*>(d))); return;
+        case 'Y': s.PutI2(*(reinterpret_cast<int16_t*>(d))); return;
+        case 'I': s.PutI4(*(reinterpret_cast<int32_t*>(d))); return;
+        case 'F': s.PutF4(*(reinterpret_cast<float*>(d))); return;
+        case 'D': s.PutF8(*(reinterpret_cast<double*>(d))); return;
+        case 'L': s.PutI8(*(reinterpret_cast<int64_t*>(d))); return;
+        case 'S':
+        case 'R':
+            s.PutU4(uint32_t(data.size()));
+            for (size_t i = 0; i < data.size(); ++i) { s.PutU1(data[i]); }
+            return;
+        case 'i':
+            N = data.size() / 4;
+            s.PutU4(uint32_t(N)); // number of elements
+            s.PutU4(0); // no encoding (1 would be zip-compressed)
+            // TODO: compress if large?
+            s.PutU4(uint32_t(data.size())); // data size
+            for (size_t i = 0; i < N; ++i) {
+                s.PutI4((reinterpret_cast<int32_t*>(d))[i]);
+            }
+            return;
+        case 'l':
+            N = data.size() / 8;
+            s.PutU4(uint32_t(N)); // number of elements
+            s.PutU4(0); // no encoding (1 would be zip-compressed)
+            // TODO: compress if large?
+            s.PutU4(uint32_t(data.size())); // data size
+            for (size_t i = 0; i < N; ++i) {
+                s.PutI8((reinterpret_cast<int64_t*>(d))[i]);
+            }
+            return;
+        case 'f':
+            N = data.size() / 4;
+            s.PutU4(uint32_t(N)); // number of elements
+            s.PutU4(0); // no encoding (1 would be zip-compressed)
+            // TODO: compress if large?
+            s.PutU4(uint32_t(data.size())); // data size
+            for (size_t i = 0; i < N; ++i) {
+                s.PutF4((reinterpret_cast<float*>(d))[i]);
+            }
+            return;
+        case 'd':
+            N = data.size() / 8;
+            s.PutU4(uint32_t(N)); // number of elements
+            s.PutU4(0); // no encoding (1 would be zip-compressed)
+            // TODO: compress if large?
+            s.PutU4(uint32_t(data.size())); // data size
+            for (size_t i = 0; i < N; ++i) {
+                s.PutF8((reinterpret_cast<double*>(d))[i]);
+            }
+            return;
+        default:
+            std::ostringstream err;
+            err << "Tried to dump property with invalid type '";
+            err << type << "'!";
+            throw DeadlyExportError(err.str());
+    }
+}
+
+void FBXExportProperty::DumpAscii(Assimp::StreamWriterLE& outstream, int indent) {
+    std::ostringstream ss;
+    ss.imbue(std::locale::classic());
+    ss.precision(15); // this seems to match official FBX SDK exports
+    DumpAscii(ss, indent);
+    outstream.PutString(ss.str());
+}
+
+void FBXExportProperty::DumpAscii(std::ostream& s, int indent) {
+    // no writing type... or anything. just shove it into the stream.
+    uint8_t* d = data.data();
+    size_t N;
+    size_t swap = data.size();
+    size_t count = 0;
+    switch (type) {
+    case 'C':
+        if (*(reinterpret_cast<uint8_t*>(d))) { s << 'T'; }
+        else { s << 'F'; }
+        return;
+    case 'Y': s << *(reinterpret_cast<int16_t*>(d)); return;
+    case 'I': s << *(reinterpret_cast<int32_t*>(d)); return;
+    case 'F': s << *(reinterpret_cast<float*>(d)); return;
+    case 'D': s << *(reinterpret_cast<double*>(d)); return;
+    case 'L': s << *(reinterpret_cast<int64_t*>(d)); return;
+    case 'S':
+        // first search to see if it has "\x00\x01" in it -
+        // which separates fields which are reversed in the ascii version.
+        // yeah.
+        // FBX, yeah.
+        for (size_t i = 0; i < data.size(); ++i) {
+            if (data[i] == '\0') {
+                swap = i;
+                break;
+            }
+        }
+    case 'R':
+        s << '"';
+        // we might as well check this now,
+        // probably it will never happen
+        for (size_t i = 0; i < data.size(); ++i) {
+            char c = data[i];
+            if (c == '"') {
+                throw runtime_error("can't handle quotes in property string");
+            }
+        }
+        // first write the SWAPPED member (if any)
+        for (size_t i = swap + 2; i < data.size(); ++i) {
+            char c = data[i];
+            s << c;
+        }
+        // then a separator
+        if (swap != data.size()) {
+            s << "::";
+        }
+        // then the initial member
+        for (size_t i = 0; i < swap; ++i) {
+            char c = data[i];
+            s << c;
+        }
+        s << '"';
+        return;
+    case 'i':
+        N = data.size() / 4; // number of elements
+        s << '*' << N << " {\n";
+        for (int i = 0; i < indent + 1; ++i) { s << '\t'; }
+        s << "a: ";
+        for (size_t i = 0; i < N; ++i) {
+            if (i > 0) { s << ','; }
+            if (count++ > 120) { s << '\n'; count = 0; }
+            s << (reinterpret_cast<int32_t*>(d))[i];
+        }
+        s << '\n';
+        for (int i = 0; i < indent; ++i) { s << '\t'; }
+        s << "} ";
+        return;
+    case 'l':
+        N = data.size() / 8;
+        s << '*' << N << " {\n";
+        for (int i = 0; i < indent + 1; ++i) { s << '\t'; }
+        s << "a: ";
+        for (size_t i = 0; i < N; ++i) {
+            if (i > 0) { s << ','; }
+            if (count++ > 120) { s << '\n'; count = 0; }
+            s << (reinterpret_cast<int64_t*>(d))[i];
+        }
+        s << '\n';
+        for (int i = 0; i < indent; ++i) { s << '\t'; }
+        s << "} ";
+        return;
+    case 'f':
+        N = data.size() / 4;
+        s << '*' << N << " {\n";
+        for (int i = 0; i < indent + 1; ++i) { s << '\t'; }
+        s << "a: ";
+        for (size_t i = 0; i < N; ++i) {
+            if (i > 0) { s << ','; }
+            if (count++ > 120) { s << '\n'; count = 0; }
+            s << (reinterpret_cast<float*>(d))[i];
+        }
+        s << '\n';
+        for (int i = 0; i < indent; ++i) { s << '\t'; }
+        s << "} ";
+        return;
+    case 'd':
+        N = data.size() / 8;
+        s << '*' << N << " {\n";
+        for (int i = 0; i < indent + 1; ++i) { s << '\t'; }
+        s << "a: ";
+        // set precision to something that can handle doubles
+        s.precision(15);
+        for (size_t i = 0; i < N; ++i) {
+            if (i > 0) { s << ','; }
+            if (count++ > 120) { s << '\n'; count = 0; }
+            s << (reinterpret_cast<double*>(d))[i];
+        }
+        s << '\n';
+        for (int i = 0; i < indent; ++i) { s << '\t'; }
+        s << "} ";
+        return;
+    default:
+        std::ostringstream err;
+        err << "Tried to dump property with invalid type '";
+        err << type << "'!";
+        throw runtime_error(err.str());
+    }
+}
+
+} // Namespace FBX
+} // Namespace Assimp
+
+#endif // ASSIMP_BUILD_NO_FBX_EXPORTER
+#endif // ASSIMP_BUILD_NO_EXPORT
diff --git a/thirdparty/assimp/code/FBX/FBXExportProperty.h b/thirdparty/assimp/code/FBX/FBXExportProperty.h
new file mode 100644
index 0000000000..d692fe6ee3
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXExportProperty.h
@@ -0,0 +1,129 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+copyright notice, this list of conditions and the
+following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other
+materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+contributors may be used to endorse or promote products
+derived from this software without specific prior
+written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file FBXExportProperty.h
+* Declares the FBX::Property helper class for fbx export.
+*/
+#ifndef AI_FBXEXPORTPROPERTY_H_INC
+#define AI_FBXEXPORTPROPERTY_H_INC
+
+#ifndef ASSIMP_BUILD_NO_FBX_EXPORTER
+
+#include <assimp/types.h> // aiMatrix4x4
+#include <assimp/StreamWriter.h> // StreamWriterLE
+
+#include <string>
+#include <vector>
+#include <ostream>
+#include <type_traits> // is_void
+
+namespace Assimp {
+namespace FBX {
+
+/** @brief FBX::Property
+ *
+ *  Holds a value of any of FBX's recognized types,
+ *  each represented by a particular one-character code.
+ *  C : 1-byte uint8, usually 0x00 or 0x01 to represent boolean false and true
+ *  Y : 2-byte int16
+ *  I : 4-byte int32
+ *  F : 4-byte float
+ *  D : 8-byte double
+ *  L : 8-byte int64
+ *  i : array of int32
+ *  f : array of float
+ *  d : array of double
+ *  l : array of int64
+ *  b : array of 1-byte booleans (0x00 or 0x01)
+ *  S : string (array of 1-byte char)
+ *  R : raw data (array of bytes)
+ */
+class FBXExportProperty {
+public:
+    // constructors for basic types.
+    // all explicit to avoid accidental typecasting
+    explicit FBXExportProperty(bool v);
+    // TODO: determine if there is actually a byte type,
+    // or if this always means <bool>. 'C' seems to imply <char>,
+    // so possibly the above was intended to represent both.
+    explicit FBXExportProperty(int16_t v);
+    explicit FBXExportProperty(int32_t v);
+    explicit FBXExportProperty(float v);
+    explicit FBXExportProperty(double v);
+    explicit FBXExportProperty(int64_t v);
+    // strings can either be stored as 'R' (raw) or 'S' (string) type
+    explicit FBXExportProperty(const char* c, bool raw = false);
+    explicit FBXExportProperty(const std::string& s, bool raw = false);
+    explicit FBXExportProperty(const std::vector<uint8_t>& r);
+    explicit FBXExportProperty(const std::vector<int32_t>& va);
+    explicit FBXExportProperty(const std::vector<int64_t>& va);
+    explicit FBXExportProperty(const std::vector<double>& va);
+    explicit FBXExportProperty(const std::vector<float>& va);
+    explicit FBXExportProperty(const aiMatrix4x4& vm);
+
+    // this will catch any type not defined above,
+    // so that we don't accidentally convert something we don't want.
+    // for example (const char*) --> (bool)... seriously wtf C++
+    template <class T>
+    explicit FBXExportProperty(T v) : type('X') {
+        static_assert(std::is_void<T>::value, "TRIED TO CREATE FBX PROPERTY WITH UNSUPPORTED TYPE, CHECK YOUR PROPERTY INSTANTIATION");
+    } // note: no line wrap so it appears verbatim on the compiler error
+
+    // the size of this property node in a binary file, in bytes
+    size_t size();
+
+    // write this property node as binary data to the given stream
+    void DumpBinary(Assimp::StreamWriterLE& s);
+    void DumpAscii(Assimp::StreamWriterLE& s, int indent = 0);
+    void DumpAscii(std::ostream& s, int indent = 0);
+    // note: make sure the ostream is in classic "C" locale
+
+private:
+    char type;
+    std::vector<uint8_t> data;
+};
+
+} // Namespace FBX
+} // Namespace Assimp
+
+#endif // ASSIMP_BUILD_NO_FBX_EXPORTER
+
+#endif // AI_FBXEXPORTPROPERTY_H_INC
diff --git a/thirdparty/assimp/code/FBX/FBXExporter.cpp b/thirdparty/assimp/code/FBX/FBXExporter.cpp
new file mode 100644
index 0000000000..153e676506
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXExporter.cpp
@@ -0,0 +1,2543 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+copyright notice, this list of conditions and the
+following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other
+materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+contributors may be used to endorse or promote products
+derived from this software without specific prior
+written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+#ifndef ASSIMP_BUILD_NO_EXPORT
+#ifndef ASSIMP_BUILD_NO_FBX_EXPORTER
+
+#include "FBXExporter.h"
+#include "FBXExportNode.h"
+#include "FBXExportProperty.h"
+#include "FBXCommon.h"
+#include "FBXUtil.h"
+
+#include <assimp/version.h> // aiGetVersion
+#include <assimp/IOSystem.hpp>
+#include <assimp/Exporter.hpp>
+#include <assimp/DefaultLogger.hpp>
+#include <assimp/StreamWriter.h> // StreamWriterLE
+#include <assimp/Exceptional.h> // DeadlyExportError
+#include <assimp/material.h> // aiTextureType
+#include <assimp/scene.h>
+#include <assimp/mesh.h>
+
+// Header files, standard library.
+#include <memory> // shared_ptr
+#include <string>
+#include <sstream> // stringstream
+#include <ctime> // localtime, tm_*
+#include <map>
+#include <set>
+#include <vector>
+#include <array>
+#include <unordered_set>
+
+// RESOURCES:
+// https://code.blender.org/2013/08/fbx-binary-file-format-specification/
+// https://wiki.blender.org/index.php/User:Mont29/Foundation/FBX_File_Structure
+
+const ai_real DEG = ai_real( 57.29577951308232087679815481 ); // degrees per radian
+
+using namespace Assimp;
+using namespace Assimp::FBX;
+
+// some constants that we'll use for writing metadata
+namespace Assimp {
+namespace FBX {
+    const std::string EXPORT_VERSION_STR = "7.4.0";
+    const uint32_t EXPORT_VERSION_INT = 7400; // 7.4 == 2014/2015
+    // FBX files have some hashed values that depend on the creation time field,
+    // but for now we don't actually know how to generate these.
+    // what we can do is set them to a known-working version.
+    // this is the data that Blender uses in their FBX export process.
+    const std::string GENERIC_CTIME = "1970-01-01 10:00:00:000";
+    const std::string GENERIC_FILEID =
+        "\x28\xb3\x2a\xeb\xb6\x24\xcc\xc2\xbf\xc8\xb0\x2a\xa9\x2b\xfc\xf1";
+    const std::string GENERIC_FOOTID =
+        "\xfa\xbc\xab\x09\xd0\xc8\xd4\x66\xb1\x76\xfb\x83\x1c\xf7\x26\x7e";
+    const std::string FOOT_MAGIC =
+        "\xf8\x5a\x8c\x6a\xde\xf5\xd9\x7e\xec\xe9\x0c\xe3\x75\x8f\x29\x0b";
+    const std::string COMMENT_UNDERLINE =
+        ";------------------------------------------------------------------";
+}
+
+    // ---------------------------------------------------------------------
+    // Worker function for exporting a scene to binary FBX.
+    // Prototyped and registered in Exporter.cpp
+    void ExportSceneFBX (
+        const char* pFile,
+        IOSystem* pIOSystem,
+        const aiScene* pScene,
+        const ExportProperties* pProperties
+    ){
+        // initialize the exporter
+        FBXExporter exporter(pScene, pProperties);
+
+        // perform binary export
+        exporter.ExportBinary(pFile, pIOSystem);
+    }
+
+    // ---------------------------------------------------------------------
+    // Worker function for exporting a scene to ASCII FBX.
+    // Prototyped and registered in Exporter.cpp
+    void ExportSceneFBXA (
+        const char* pFile,
+        IOSystem* pIOSystem,
+        const aiScene* pScene,
+        const ExportProperties* pProperties
+
+    ){
+        // initialize the exporter
+        FBXExporter exporter(pScene, pProperties);
+
+        // perform ascii export
+        exporter.ExportAscii(pFile, pIOSystem);
+    }
+
+} // end of namespace Assimp
+
+FBXExporter::FBXExporter ( const aiScene* pScene, const ExportProperties* pProperties )
+: binary(false)
+, mScene(pScene)
+, mProperties(pProperties)
+, outfile()
+, connections()
+, mesh_uids()
+, material_uids()
+, node_uids() {
+    // will probably need to determine UIDs, connections, etc here.
+    // basically anything that needs to be known
+    // before we start writing sections to the stream.
+}
+
+void FBXExporter::ExportBinary (
+    const char* pFile,
+    IOSystem* pIOSystem
+){
+    // remember that we're exporting in binary mode
+    binary = true;
+
+    // we're not currently using these preferences,
+    // but clang will cry about it if we never touch it.
+    // TODO: some of these might be relevant to export
+    (void)mProperties;
+
+    // open the indicated file for writing (in binary mode)
+    outfile.reset(pIOSystem->Open(pFile,"wb"));
+    if (!outfile) {
+        throw DeadlyExportError(
+            "could not open output .fbx file: " + std::string(pFile)
+        );
+    }
+
+    // first a binary-specific file header
+    WriteBinaryHeader();
+
+    // the rest of the file is in node entries.
+    // we have to serialize each entry before we write to the output,
+    // as the first thing we write is the byte offset of the _next_ entry.
+    // Either that or we can skip back to write the offset when we finish.
+    WriteAllNodes();
+
+    // finally we have a binary footer to the file
+    WriteBinaryFooter();
+
+    // explicitly release file pointer,
+    // so we don't have to rely on class destruction.
+    outfile.reset();
+}
+
+void FBXExporter::ExportAscii (
+    const char* pFile,
+    IOSystem* pIOSystem
+){
+    // remember that we're exporting in ascii mode
+    binary = false;
+
+    // open the indicated file for writing in text mode
+    outfile.reset(pIOSystem->Open(pFile,"wt"));
+    if (!outfile) {
+        throw DeadlyExportError(
+            "could not open output .fbx file: " + std::string(pFile)
+        );
+    }
+
+    // write the ascii header
+    WriteAsciiHeader();
+
+    // write all the sections
+    WriteAllNodes();
+
+    // make sure the file ends with a newline.
+    // note: if the file is opened in text mode,
+    // this should do the right cross-platform thing.
+    outfile->Write("\n", 1, 1);
+
+    // explicitly release file pointer,
+    // so we don't have to rely on class destruction.
+    outfile.reset();
+}
+
+void FBXExporter::WriteAsciiHeader()
+{
+    // basically just a comment at the top of the file
+    std::stringstream head;
+    head << "; FBX " << EXPORT_VERSION_STR << " project file\n";
+    head << "; Created by the Open Asset Import Library (Assimp)\n";
+    head << "; http://assimp.org\n";
+    head << "; -------------------------------------------------\n";
+    const std::string ascii_header = head.str();
+    outfile->Write(ascii_header.c_str(), ascii_header.size(), 1);
+}
+
+void FBXExporter::WriteAsciiSectionHeader(const std::string& title)
+{
+    StreamWriterLE outstream(outfile);
+    std::stringstream s;
+    s << "\n\n; " << title << '\n';
+    s << FBX::COMMENT_UNDERLINE << "\n";
+    outstream.PutString(s.str());
+}
+
+void FBXExporter::WriteBinaryHeader()
+{
+    // first a specific sequence of 23 bytes, always the same
+    const char binary_header[24] = "Kaydara FBX Binary\x20\x20\x00\x1a\x00";
+    outfile->Write(binary_header, 1, 23);
+
+    // then FBX version number, "multiplied" by 1000, as little-endian uint32.
+    // so 7.3 becomes 7300 == 0x841C0000, 7.4 becomes 7400 == 0xE81C0000, etc
+    {
+        StreamWriterLE outstream(outfile);
+        outstream.PutU4(EXPORT_VERSION_INT);
+    } // StreamWriter destructor writes the data to the file
+
+    // after this the node data starts immediately
+    // (probably with the FBXHEaderExtension node)
+}
+
+void FBXExporter::WriteBinaryFooter()
+{
+    outfile->Write(NULL_RECORD.c_str(), NULL_RECORD.size(), 1);
+
+    outfile->Write(GENERIC_FOOTID.c_str(), GENERIC_FOOTID.size(), 1);
+
+    // here some padding is added for alignment to 16 bytes.
+    // if already aligned, the full 16 bytes is added.
+    size_t pos = outfile->Tell();
+    size_t pad = 16 - (pos % 16);
+    for (size_t i = 0; i < pad; ++i) {
+        outfile->Write("\x00", 1, 1);
+    }
+
+    // not sure what this is, but it seems to always be 0 in modern files
+    for (size_t i = 0; i < 4; ++i) {
+        outfile->Write("\x00", 1, 1);
+    }
+
+    // now the file version again
+    {
+        StreamWriterLE outstream(outfile);
+        outstream.PutU4(EXPORT_VERSION_INT);
+    } // StreamWriter destructor writes the data to the file
+
+    // and finally some binary footer added to all files
+    for (size_t i = 0; i < 120; ++i) {
+        outfile->Write("\x00", 1, 1);
+    }
+    outfile->Write(FOOT_MAGIC.c_str(), FOOT_MAGIC.size(), 1);
+}
+
+void FBXExporter::WriteAllNodes ()
+{
+    // header
+    // (and fileid, creation time, creator, if binary)
+    WriteHeaderExtension();
+
+    // global settings
+    WriteGlobalSettings();
+
+    // documents
+    WriteDocuments();
+
+    // references
+    WriteReferences();
+
+    // definitions
+    WriteDefinitions();
+
+    // objects
+    WriteObjects();
+
+    // connections
+    WriteConnections();
+
+    // WriteTakes? (deprecated since at least 2015 (fbx 7.4))
+}
+
+//FBXHeaderExtension top-level node
+void FBXExporter::WriteHeaderExtension ()
+{
+    if (!binary) {
+        // no title, follows directly from the top comment
+    }
+    FBX::Node n("FBXHeaderExtension");
+    StreamWriterLE outstream(outfile);
+    int indent = 0;
+
+    // begin node
+    n.Begin(outstream, binary, indent);
+
+    // write properties
+    // (none)
+
+    // finish properties
+    n.EndProperties(outstream, binary, indent, 0);
+
+    // begin children
+    n.BeginChildren(outstream, binary, indent);
+
+    indent = 1;
+
+    // write child nodes
+    FBX::Node::WritePropertyNode(
+        "FBXHeaderVersion", int32_t(1003), outstream, binary, indent
+    );
+    FBX::Node::WritePropertyNode(
+        "FBXVersion", int32_t(EXPORT_VERSION_INT), outstream, binary, indent
+    );
+    if (binary) {
+        FBX::Node::WritePropertyNode(
+            "EncryptionType", int32_t(0), outstream, binary, indent
+        );
+    }
+
+    FBX::Node CreationTimeStamp("CreationTimeStamp");
+    time_t rawtime;
+    time(&rawtime);
+    struct tm * now = localtime(&rawtime);
+    CreationTimeStamp.AddChild("Version", int32_t(1000));
+    CreationTimeStamp.AddChild("Year", int32_t(now->tm_year + 1900));
+    CreationTimeStamp.AddChild("Month", int32_t(now->tm_mon + 1));
+    CreationTimeStamp.AddChild("Day", int32_t(now->tm_mday));
+    CreationTimeStamp.AddChild("Hour", int32_t(now->tm_hour));
+    CreationTimeStamp.AddChild("Minute", int32_t(now->tm_min));
+    CreationTimeStamp.AddChild("Second", int32_t(now->tm_sec));
+    CreationTimeStamp.AddChild("Millisecond", int32_t(0));
+    CreationTimeStamp.Dump(outstream, binary, indent);
+
+    std::stringstream creator;
+    creator << "Open Asset Import Library (Assimp) " << aiGetVersionMajor()
+            << "." << aiGetVersionMinor() << "." << aiGetVersionRevision();
+    FBX::Node::WritePropertyNode(
+        "Creator", creator.str(), outstream, binary, indent
+    );
+
+    //FBX::Node sceneinfo("SceneInfo");
+    //sceneinfo.AddProperty("GlobalInfo" + FBX::SEPARATOR + "SceneInfo");
+    // not sure if any of this is actually needed,
+    // so just write an empty node for now.
+    //sceneinfo.Dump(outstream, binary, indent);
+
+    indent = 0;
+
+    // finish node
+    n.End(outstream, binary, indent, true);
+
+    // that's it for FBXHeaderExtension...
+    if (!binary) { return; }
+
+    // but binary files also need top-level FileID, CreationTime, Creator:
+    std::vector<uint8_t> raw(GENERIC_FILEID.size());
+    for (size_t i = 0; i < GENERIC_FILEID.size(); ++i) {
+        raw[i] = uint8_t(GENERIC_FILEID[i]);
+    }
+    FBX::Node::WritePropertyNode(
+        "FileId", raw, outstream, binary, indent
+    );
+    FBX::Node::WritePropertyNode(
+        "CreationTime", GENERIC_CTIME, outstream, binary, indent
+    );
+    FBX::Node::WritePropertyNode(
+        "Creator", creator.str(), outstream, binary, indent
+    );
+}
+
+void FBXExporter::WriteGlobalSettings ()
+{
+    if (!binary) {
+        // no title, follows directly from the header extension
+    }
+    FBX::Node gs("GlobalSettings");
+    gs.AddChild("Version", int32_t(1000));
+
+    FBX::Node p("Properties70");
+    p.AddP70int("UpAxis", 1);
+    p.AddP70int("UpAxisSign", 1);
+    p.AddP70int("FrontAxis", 2);
+    p.AddP70int("FrontAxisSign", 1);
+    p.AddP70int("CoordAxis", 0);
+    p.AddP70int("CoordAxisSign", 1);
+    p.AddP70int("OriginalUpAxis", 1);
+    p.AddP70int("OriginalUpAxisSign", 1);
+    p.AddP70double("UnitScaleFactor", 1.0);
+    p.AddP70double("OriginalUnitScaleFactor", 1.0);
+    p.AddP70color("AmbientColor", 0.0, 0.0, 0.0);
+    p.AddP70string("DefaultCamera", "Producer Perspective");
+    p.AddP70enum("TimeMode", 11);
+    p.AddP70enum("TimeProtocol", 2);
+    p.AddP70enum("SnapOnFrameMode", 0);
+    p.AddP70time("TimeSpanStart", 0); // TODO: animation support
+    p.AddP70time("TimeSpanStop", FBX::SECOND); // TODO: animation support
+    p.AddP70double("CustomFrameRate", -1.0);
+    p.AddP70("TimeMarker", "Compound", "", ""); // not sure what this is
+    p.AddP70int("CurrentTimeMarker", -1);
+    gs.AddChild(p);
+
+    gs.Dump(outfile, binary, 0);
+}
+
+void FBXExporter::WriteDocuments ()
+{
+    if (!binary) {
+        WriteAsciiSectionHeader("Documents Description");
+    }
+    
+    // not sure what the use of multiple documents would be,
+    // or whether any end-application supports it
+    FBX::Node docs("Documents");
+    docs.AddChild("Count", int32_t(1));
+    FBX::Node doc("Document");
+
+    // generate uid
+    int64_t uid = generate_uid();
+    doc.AddProperties(uid, "", "Scene");
+    FBX::Node p("Properties70");
+    p.AddP70("SourceObject", "object", "", ""); // what is this even for?
+    p.AddP70string("ActiveAnimStackName", ""); // should do this properly?
+    doc.AddChild(p);
+
+    // UID for root node in scene hierarchy.
+    // always set to 0 in the case of a single document.
+    // not sure what happens if more than one document exists,
+    // but that won't matter to us as we're exporting a single scene.
+    doc.AddChild("RootNode", int64_t(0));
+
+    docs.AddChild(doc);
+    docs.Dump(outfile, binary, 0);
+}
+
+void FBXExporter::WriteReferences ()
+{
+    if (!binary) {
+        WriteAsciiSectionHeader("Document References");
+    }
+    // always empty for now.
+    // not really sure what this is for.
+    FBX::Node n("References");
+    n.force_has_children = true;
+    n.Dump(outfile, binary, 0);
+}
+
+
+// ---------------------------------------------------------------
+// some internal helper functions used for writing the definitions
+// (before any actual data is written)
+// ---------------------------------------------------------------
+
+size_t count_nodes(const aiNode* n) {
+    size_t count = 1;
+    for (size_t i = 0; i < n->mNumChildren; ++i) {
+        count += count_nodes(n->mChildren[i]);
+    }
+    return count;
+}
+
+bool has_phong_mat(const aiScene* scene)
+{
+    // just search for any material with a shininess exponent
+    for (size_t i = 0; i < scene->mNumMaterials; ++i) {
+        aiMaterial* mat = scene->mMaterials[i];
+        float shininess = 0;
+        mat->Get(AI_MATKEY_SHININESS, shininess);
+        if (shininess > 0) {
+            return true;
+        }
+    }
+    return false;
+}
+
+size_t count_images(const aiScene* scene) {
+    std::unordered_set<std::string> images;
+    aiString texpath;
+    for (size_t i = 0; i < scene->mNumMaterials; ++i) {
+        aiMaterial* mat = scene->mMaterials[i];
+        for (
+            size_t tt = aiTextureType_DIFFUSE;
+            tt < aiTextureType_UNKNOWN;
+            ++tt
+        ){
+            const aiTextureType textype = static_cast<aiTextureType>(tt);
+            const size_t texcount = mat->GetTextureCount(textype);
+            for (unsigned int j = 0; j < texcount; ++j) {
+                mat->GetTexture(textype, j, &texpath);
+                images.insert(std::string(texpath.C_Str()));
+            }
+        }
+    }
+    return images.size();
+}
+
+size_t count_textures(const aiScene* scene) {
+    size_t count = 0;
+    for (size_t i = 0; i < scene->mNumMaterials; ++i) {
+        aiMaterial* mat = scene->mMaterials[i];
+        for (
+            size_t tt = aiTextureType_DIFFUSE;
+            tt < aiTextureType_UNKNOWN;
+            ++tt
+        ){
+            // TODO: handle layered textures
+            if (mat->GetTextureCount(static_cast<aiTextureType>(tt)) > 0) {
+                count += 1;
+            }
+        }
+    }
+    return count;
+}
+
+size_t count_deformers(const aiScene* scene) {
+    size_t count = 0;
+    for (size_t i = 0; i < scene->mNumMeshes; ++i) {
+        const size_t n = scene->mMeshes[i]->mNumBones;
+        if (n) {
+            // 1 main deformer, 1 subdeformer per bone
+            count += n + 1;
+        }
+    }
+    return count;
+}
+
+void FBXExporter::WriteDefinitions ()
+{
+    // basically this is just bookkeeping:
+    // determining how many of each type of object there are
+    // and specifying the base properties to use when otherwise unspecified.
+
+    // ascii section header
+    if (!binary) {
+        WriteAsciiSectionHeader("Object definitions");
+    }
+
+    // we need to count the objects
+    int32_t count;
+    int32_t total_count = 0;
+
+    // and store them
+    std::vector<FBX::Node> object_nodes;
+    FBX::Node n, pt, p;
+
+    // GlobalSettings
+    // this seems to always be here in Maya exports
+    n = FBX::Node("ObjectType", "GlobalSettings");
+    count = 1;
+    n.AddChild("Count", count);
+    object_nodes.push_back(n);
+    total_count += count;
+
+    // AnimationStack / FbxAnimStack
+    // this seems to always be here in Maya exports,
+    // but no harm seems to come of leaving it out.
+    count = mScene->mNumAnimations;
+    if (count) {
+        n = FBX::Node("ObjectType", "AnimationStack");
+        n.AddChild("Count", count);
+        pt = FBX::Node("PropertyTemplate", "FbxAnimStack");
+        p = FBX::Node("Properties70");
+        p.AddP70string("Description", "");
+        p.AddP70time("LocalStart", 0);
+        p.AddP70time("LocalStop", 0);
+        p.AddP70time("ReferenceStart", 0);
+        p.AddP70time("ReferenceStop", 0);
+        pt.AddChild(p);
+        n.AddChild(pt);
+        object_nodes.push_back(n);
+        total_count += count;
+    }
+
+    // AnimationLayer / FbxAnimLayer
+    // this seems to always be here in Maya exports,
+    // but no harm seems to come of leaving it out.
+    // Assimp doesn't support animation layers,
+    // so there will be one per aiAnimation
+    count = mScene->mNumAnimations;
+    if (count) {
+        n = FBX::Node("ObjectType", "AnimationLayer");
+        n.AddChild("Count", count);
+        pt = FBX::Node("PropertyTemplate", "FBXAnimLayer");
+        p = FBX::Node("Properties70");
+        p.AddP70("Weight", "Number", "", "A", double(100));
+        p.AddP70bool("Mute", 0);
+        p.AddP70bool("Solo", 0);
+        p.AddP70bool("Lock", 0);
+        p.AddP70color("Color", 0.8, 0.8, 0.8);
+        p.AddP70("BlendMode", "enum", "", "", int32_t(0));
+        p.AddP70("RotationAccumulationMode", "enum", "", "", int32_t(0));
+        p.AddP70("ScaleAccumulationMode", "enum", "", "", int32_t(0));
+        p.AddP70("BlendModeBypass", "ULongLong", "", "", int64_t(0));
+        pt.AddChild(p);
+        n.AddChild(pt);
+        object_nodes.push_back(n);
+        total_count += count;
+    }
+
+    // NodeAttribute
+    // this is completely absurd.
+    // there can only be one "NodeAttribute" template,
+    // but FbxSkeleton, FbxCamera, FbxLight all are "NodeAttributes".
+    // so if only one exists we should set the template for that,
+    // otherwise... we just pick one :/.
+    // the others have to set all their properties every instance,
+    // because there's no template.
+    count = 1; // TODO: select properly
+    if (count) {
+        // FbxSkeleton
+        n = FBX::Node("ObjectType", "NodeAttribute");
+        n.AddChild("Count", count);
+        pt = FBX::Node("PropertyTemplate", "FbxSkeleton");
+        p = FBX::Node("Properties70");
+        p.AddP70color("Color", 0.8, 0.8, 0.8);
+        p.AddP70double("Size", 33.333333333333);
+        p.AddP70("LimbLength", "double", "Number", "H", double(1));
+        // note: not sure what the "H" flag is for - hidden?
+        pt.AddChild(p);
+        n.AddChild(pt);
+        object_nodes.push_back(n);
+        total_count += count;
+    }
+
+    // Model / FbxNode
+    // <~~ node hierarchy
+    count = int32_t(count_nodes(mScene->mRootNode)) - 1; // (not counting root node)
+    if (count) {
+        n = FBX::Node("ObjectType", "Model");
+        n.AddChild("Count", count);
+        pt = FBX::Node("PropertyTemplate", "FbxNode");
+        p = FBX::Node("Properties70");
+        p.AddP70enum("QuaternionInterpolate", 0);
+        p.AddP70vector("RotationOffset", 0.0, 0.0, 0.0);
+        p.AddP70vector("RotationPivot", 0.0, 0.0, 0.0);
+        p.AddP70vector("ScalingOffset", 0.0, 0.0, 0.0);
+        p.AddP70vector("ScalingPivot", 0.0, 0.0, 0.0);
+        p.AddP70bool("TranslationActive", 0);
+        p.AddP70vector("TranslationMin", 0.0, 0.0, 0.0);
+        p.AddP70vector("TranslationMax", 0.0, 0.0, 0.0);
+        p.AddP70bool("TranslationMinX", 0);
+        p.AddP70bool("TranslationMinY", 0);
+        p.AddP70bool("TranslationMinZ", 0);
+        p.AddP70bool("TranslationMaxX", 0);
+        p.AddP70bool("TranslationMaxY", 0);
+        p.AddP70bool("TranslationMaxZ", 0);
+        p.AddP70enum("RotationOrder", 0);
+        p.AddP70bool("RotationSpaceForLimitOnly", 0);
+        p.AddP70double("RotationStiffnessX", 0.0);
+        p.AddP70double("RotationStiffnessY", 0.0);
+        p.AddP70double("RotationStiffnessZ", 0.0);
+        p.AddP70double("AxisLen", 10.0);
+        p.AddP70vector("PreRotation", 0.0, 0.0, 0.0);
+        p.AddP70vector("PostRotation", 0.0, 0.0, 0.0);
+        p.AddP70bool("RotationActive", 0);
+        p.AddP70vector("RotationMin", 0.0, 0.0, 0.0);
+        p.AddP70vector("RotationMax", 0.0, 0.0, 0.0);
+        p.AddP70bool("RotationMinX", 0);
+        p.AddP70bool("RotationMinY", 0);
+        p.AddP70bool("RotationMinZ", 0);
+        p.AddP70bool("RotationMaxX", 0);
+        p.AddP70bool("RotationMaxY", 0);
+        p.AddP70bool("RotationMaxZ", 0);
+        p.AddP70enum("InheritType", 0);
+        p.AddP70bool("ScalingActive", 0);
+        p.AddP70vector("ScalingMin", 0.0, 0.0, 0.0);
+        p.AddP70vector("ScalingMax", 1.0, 1.0, 1.0);
+        p.AddP70bool("ScalingMinX", 0);
+        p.AddP70bool("ScalingMinY", 0);
+        p.AddP70bool("ScalingMinZ", 0);
+        p.AddP70bool("ScalingMaxX", 0);
+        p.AddP70bool("ScalingMaxY", 0);
+        p.AddP70bool("ScalingMaxZ", 0);
+        p.AddP70vector("GeometricTranslation", 0.0, 0.0, 0.0);
+        p.AddP70vector("GeometricRotation", 0.0, 0.0, 0.0);
+        p.AddP70vector("GeometricScaling", 1.0, 1.0, 1.0);
+        p.AddP70double("MinDampRangeX", 0.0);
+        p.AddP70double("MinDampRangeY", 0.0);
+        p.AddP70double("MinDampRangeZ", 0.0);
+        p.AddP70double("MaxDampRangeX", 0.0);
+        p.AddP70double("MaxDampRangeY", 0.0);
+        p.AddP70double("MaxDampRangeZ", 0.0);
+        p.AddP70double("MinDampStrengthX", 0.0);
+        p.AddP70double("MinDampStrengthY", 0.0);
+        p.AddP70double("MinDampStrengthZ", 0.0);
+        p.AddP70double("MaxDampStrengthX", 0.0);
+        p.AddP70double("MaxDampStrengthY", 0.0);
+        p.AddP70double("MaxDampStrengthZ", 0.0);
+        p.AddP70double("PreferedAngleX", 0.0);
+        p.AddP70double("PreferedAngleY", 0.0);
+        p.AddP70double("PreferedAngleZ", 0.0);
+        p.AddP70("LookAtProperty", "object", "", "");
+        p.AddP70("UpVectorProperty", "object", "", "");
+        p.AddP70bool("Show", 1);
+        p.AddP70bool("NegativePercentShapeSupport", 1);
+        p.AddP70int("DefaultAttributeIndex", -1);
+        p.AddP70bool("Freeze", 0);
+        p.AddP70bool("LODBox", 0);
+        p.AddP70(
+            "Lcl Translation", "Lcl Translation", "", "A",
+            double(0), double(0), double(0)
+        );
+        p.AddP70(
+            "Lcl Rotation", "Lcl Rotation", "", "A",
+            double(0), double(0), double(0)
+        );
+        p.AddP70(
+            "Lcl Scaling", "Lcl Scaling", "", "A",
+            double(1), double(1), double(1)
+        );
+        p.AddP70("Visibility", "Visibility", "", "A", double(1));
+        p.AddP70(
+            "Visibility Inheritance", "Visibility Inheritance", "", "",
+            int32_t(1)
+        );
+        pt.AddChild(p);
+        n.AddChild(pt);
+        object_nodes.push_back(n);
+        total_count += count;
+    }
+
+    // Geometry / FbxMesh
+    // <~~ aiMesh
+    count = mScene->mNumMeshes;
+    if (count) {
+        n = FBX::Node("ObjectType", "Geometry");
+        n.AddChild("Count", count);
+        pt = FBX::Node("PropertyTemplate", "FbxMesh");
+        p = FBX::Node("Properties70");
+        p.AddP70color("Color", 0, 0, 0);
+        p.AddP70vector("BBoxMin", 0, 0, 0);
+        p.AddP70vector("BBoxMax", 0, 0, 0);
+        p.AddP70bool("Primary Visibility", 1);
+        p.AddP70bool("Casts Shadows", 1);
+        p.AddP70bool("Receive Shadows", 1);
+        pt.AddChild(p);
+        n.AddChild(pt);
+        object_nodes.push_back(n);
+        total_count += count;
+    }
+
+    // Material / FbxSurfacePhong, FbxSurfaceLambert, FbxSurfaceMaterial
+    // <~~ aiMaterial
+    // basically if there's any phong material this is defined as phong,
+    // and otherwise lambert.
+    // More complex materials cause a bare-bones FbxSurfaceMaterial definition
+    // and are treated specially, as they're not really supported by FBX.
+    // TODO: support Maya's Stingray PBS material
+    count = mScene->mNumMaterials;
+    if (count) {
+        bool has_phong = has_phong_mat(mScene);
+        n = FBX::Node("ObjectType", "Material");
+        n.AddChild("Count", count);
+        pt = FBX::Node("PropertyTemplate");
+        if (has_phong) {
+            pt.AddProperty("FbxSurfacePhong");
+        } else {
+            pt.AddProperty("FbxSurfaceLambert");
+        }
+        p = FBX::Node("Properties70");
+        if (has_phong) {
+            p.AddP70string("ShadingModel", "Phong");
+        } else {
+            p.AddP70string("ShadingModel", "Lambert");
+        }
+        p.AddP70bool("MultiLayer", 0);
+        p.AddP70colorA("EmissiveColor", 0.0, 0.0, 0.0);
+        p.AddP70numberA("EmissiveFactor", 1.0);
+        p.AddP70colorA("AmbientColor", 0.2, 0.2, 0.2);
+        p.AddP70numberA("AmbientFactor", 1.0);
+        p.AddP70colorA("DiffuseColor", 0.8, 0.8, 0.8);
+        p.AddP70numberA("DiffuseFactor", 1.0);
+        p.AddP70vector("Bump", 0.0, 0.0, 0.0);
+        p.AddP70vector("NormalMap", 0.0, 0.0, 0.0);
+        p.AddP70double("BumpFactor", 1.0);
+        p.AddP70colorA("TransparentColor", 0.0, 0.0, 0.0);
+        p.AddP70numberA("TransparencyFactor", 0.0);
+        p.AddP70color("DisplacementColor", 0.0, 0.0, 0.0);
+        p.AddP70double("DisplacementFactor", 1.0);
+        p.AddP70color("VectorDisplacementColor", 0.0, 0.0, 0.0);
+        p.AddP70double("VectorDisplacementFactor", 1.0);
+        if (has_phong) {
+            p.AddP70colorA("SpecularColor", 0.2, 0.2, 0.2);
+            p.AddP70numberA("SpecularFactor", 1.0);
+            p.AddP70numberA("ShininessExponent", 20.0);
+            p.AddP70colorA("ReflectionColor", 0.0, 0.0, 0.0);
+            p.AddP70numberA("ReflectionFactor", 1.0);
+        }
+        pt.AddChild(p);
+        n.AddChild(pt);
+        object_nodes.push_back(n);
+        total_count += count;
+    }
+
+    // Video / FbxVideo
+    // one for each image file.
+    count = int32_t(count_images(mScene));
+    if (count) {
+        n = FBX::Node("ObjectType", "Video");
+        n.AddChild("Count", count);
+        pt = FBX::Node("PropertyTemplate", "FbxVideo");
+        p = FBX::Node("Properties70");
+        p.AddP70bool("ImageSequence", 0);
+        p.AddP70int("ImageSequenceOffset", 0);
+        p.AddP70double("FrameRate", 0.0);
+        p.AddP70int("LastFrame", 0);
+        p.AddP70int("Width", 0);
+        p.AddP70int("Height", 0);
+        p.AddP70("Path", "KString", "XRefUrl", "", "");
+        p.AddP70int("StartFrame", 0);
+        p.AddP70int("StopFrame", 0);
+        p.AddP70double("PlaySpeed", 0.0);
+        p.AddP70time("Offset", 0);
+        p.AddP70enum("InterlaceMode", 0);
+        p.AddP70bool("FreeRunning", 0);
+        p.AddP70bool("Loop", 0);
+        p.AddP70enum("AccessMode", 0);
+        pt.AddChild(p);
+        n.AddChild(pt);
+        object_nodes.push_back(n);
+        total_count += count;
+    }
+
+    // Texture / FbxFileTexture
+    // <~~ aiTexture
+    count = int32_t(count_textures(mScene));
+    if (count) {
+        n = FBX::Node("ObjectType", "Texture");
+        n.AddChild("Count", count);
+        pt = FBX::Node("PropertyTemplate", "FbxFileTexture");
+        p = FBX::Node("Properties70");
+        p.AddP70enum("TextureTypeUse", 0);
+        p.AddP70numberA("Texture alpha", 1.0);
+        p.AddP70enum("CurrentMappingType", 0);
+        p.AddP70enum("WrapModeU", 0);
+        p.AddP70enum("WrapModeV", 0);
+        p.AddP70bool("UVSwap", 0);
+        p.AddP70bool("PremultiplyAlpha", 1);
+        p.AddP70vectorA("Translation", 0.0, 0.0, 0.0);
+        p.AddP70vectorA("Rotation", 0.0, 0.0, 0.0);
+        p.AddP70vectorA("Scaling", 1.0, 1.0, 1.0);
+        p.AddP70vector("TextureRotationPivot", 0.0, 0.0, 0.0);
+        p.AddP70vector("TextureScalingPivot", 0.0, 0.0, 0.0);
+        p.AddP70enum("CurrentTextureBlendMode", 1);
+        p.AddP70string("UVSet", "default");
+        p.AddP70bool("UseMaterial", 0);
+        p.AddP70bool("UseMipMap", 0);
+        pt.AddChild(p);
+        n.AddChild(pt);
+        object_nodes.push_back(n);
+        total_count += count;
+    }
+
+    // AnimationCurveNode / FbxAnimCurveNode
+    count = mScene->mNumAnimations * 3;
+    if (count) {
+        n = FBX::Node("ObjectType", "AnimationCurveNode");
+        n.AddChild("Count", count);
+        pt = FBX::Node("PropertyTemplate", "FbxAnimCurveNode");
+        p = FBX::Node("Properties70");
+        p.AddP70("d", "Compound", "", "");
+        pt.AddChild(p);
+        n.AddChild(pt);
+        object_nodes.push_back(n);
+        total_count += count;
+    }
+
+    // AnimationCurve / FbxAnimCurve
+    count = mScene->mNumAnimations * 9;
+    if (count) {
+        n = FBX::Node("ObjectType", "AnimationCurve");
+        n.AddChild("Count", count);
+        object_nodes.push_back(n);
+        total_count += count;
+    }
+
+    // Pose
+    count = 0;
+    for (size_t i = 0; i < mScene->mNumMeshes; ++i) {
+        aiMesh* mesh = mScene->mMeshes[i];
+        if (mesh->HasBones()) { ++count; }
+    }
+    if (count) {
+        n = FBX::Node("ObjectType", "Pose");
+        n.AddChild("Count", count);
+        object_nodes.push_back(n);
+        total_count += count;
+    }
+
+    // Deformer
+    count = int32_t(count_deformers(mScene));
+    if (count) {
+        n = FBX::Node("ObjectType", "Deformer");
+        n.AddChild("Count", count);
+        object_nodes.push_back(n);
+        total_count += count;
+    }
+
+    // (template)
+    count = 0;
+    if (count) {
+        n = FBX::Node("ObjectType", "");
+        n.AddChild("Count", count);
+        pt = FBX::Node("PropertyTemplate", "");
+        p = FBX::Node("Properties70");
+        pt.AddChild(p);
+        n.AddChild(pt);
+        object_nodes.push_back(n);
+        total_count += count;
+    }
+
+    // now write it all
+    FBX::Node defs("Definitions");
+    defs.AddChild("Version", int32_t(100));
+    defs.AddChild("Count", int32_t(total_count));
+    for (auto &n : object_nodes) { defs.AddChild(n); }
+    defs.Dump(outfile, binary, 0);
+}
+
+
+// -------------------------------------------------------------------
+// some internal helper functions used for writing the objects section
+// (which holds the actual data)
+// -------------------------------------------------------------------
+
+aiNode* get_node_for_mesh(unsigned int meshIndex, aiNode* node)
+{
+    for (size_t i = 0; i < node->mNumMeshes; ++i) {
+        if (node->mMeshes[i] == meshIndex) {
+            return node;
+        }
+    }
+    for (size_t i = 0; i < node->mNumChildren; ++i) {
+        aiNode* ret = get_node_for_mesh(meshIndex, node->mChildren[i]);
+        if (ret) { return ret; }
+    }
+    return nullptr;
+}
+
+aiMatrix4x4 get_world_transform(const aiNode* node, const aiScene* scene)
+{
+    std::vector<const aiNode*> node_chain;
+    while (node != scene->mRootNode) {
+        node_chain.push_back(node);
+        node = node->mParent;
+    }
+    aiMatrix4x4 transform;
+    for (auto n = node_chain.rbegin(); n != node_chain.rend(); ++n) {
+        transform *= (*n)->mTransformation;
+    }
+    return transform;
+}
+
+int64_t to_ktime(double ticks, const aiAnimation* anim) {
+    if (anim->mTicksPerSecond <= 0) {
+        return static_cast<int64_t>(ticks) * FBX::SECOND;
+    }
+    return (static_cast<int64_t>(ticks) / static_cast<int64_t>(anim->mTicksPerSecond)) * FBX::SECOND;
+}
+
+int64_t to_ktime(double time) {
+    return (static_cast<int64_t>(time * FBX::SECOND));
+}
+
+void FBXExporter::WriteObjects ()
+{
+    if (!binary) {
+        WriteAsciiSectionHeader("Object properties");
+    }
+    // numbers should match those given in definitions! make sure to check
+    StreamWriterLE outstream(outfile);
+    FBX::Node object_node("Objects");
+    int indent = 0;
+    object_node.Begin(outstream, binary, indent);
+    object_node.EndProperties(outstream, binary, indent);
+    object_node.BeginChildren(outstream, binary, indent);
+
+    // geometry (aiMesh)
+    mesh_uids.clear();
+    indent = 1;
+    for (size_t mi = 0; mi < mScene->mNumMeshes; ++mi) {
+        // it's all about this mesh
+        aiMesh* m = mScene->mMeshes[mi];
+
+        // start the node record
+        FBX::Node n("Geometry");
+        int64_t uid = generate_uid();
+        mesh_uids.push_back(uid);
+        n.AddProperty(uid);
+        n.AddProperty(FBX::SEPARATOR + "Geometry");
+        n.AddProperty("Mesh");
+        n.Begin(outstream, binary, indent);
+        n.DumpProperties(outstream, binary, indent);
+        n.EndProperties(outstream, binary, indent);
+        n.BeginChildren(outstream, binary, indent);
+        indent = 2;
+
+        // output vertex data - each vertex should be unique (probably)
+        std::vector<double> flattened_vertices;
+        // index of original vertex in vertex data vector
+        std::vector<int32_t> vertex_indices;
+        // map of vertex value to its index in the data vector
+        std::map<aiVector3D,size_t> index_by_vertex_value;
+        int32_t index = 0;
+        for (size_t vi = 0; vi < m->mNumVertices; ++vi) {
+            aiVector3D vtx = m->mVertices[vi];
+            auto elem = index_by_vertex_value.find(vtx);
+            if (elem == index_by_vertex_value.end()) {
+                vertex_indices.push_back(index);
+                index_by_vertex_value[vtx] = index;
+                flattened_vertices.push_back(vtx[0]);
+                flattened_vertices.push_back(vtx[1]);
+                flattened_vertices.push_back(vtx[2]);
+                ++index;
+            } else {
+                vertex_indices.push_back(int32_t(elem->second));
+            }
+        }
+        FBX::Node::WritePropertyNode(
+            "Vertices", flattened_vertices, outstream, binary, indent
+        );
+
+        // output polygon data as a flattened array of vertex indices.
+        // the last vertex index of each polygon is negated and - 1
+        std::vector<int32_t> polygon_data;
+        for (size_t fi = 0; fi < m->mNumFaces; ++fi) {
+            const aiFace &f = m->mFaces[fi];
+            for (size_t pvi = 0; pvi < f.mNumIndices - 1; ++pvi) {
+                polygon_data.push_back(vertex_indices[f.mIndices[pvi]]);
+            }
+            polygon_data.push_back(
+                -1 - vertex_indices[f.mIndices[f.mNumIndices-1]]
+            );
+        }
+        FBX::Node::WritePropertyNode(
+            "PolygonVertexIndex", polygon_data, outstream, binary, indent
+        );
+
+        // here could be edges but they're insane.
+        // it's optional anyway, so let's ignore it.
+
+        FBX::Node::WritePropertyNode(
+            "GeometryVersion", int32_t(124), outstream, binary, indent
+        );
+
+        // normals, if any
+        if (m->HasNormals()) {
+            FBX::Node normals("LayerElementNormal", int32_t(0));
+            normals.Begin(outstream, binary, indent);
+            normals.DumpProperties(outstream, binary, indent);
+            normals.EndProperties(outstream, binary, indent);
+            normals.BeginChildren(outstream, binary, indent);
+            indent = 3;
+            FBX::Node::WritePropertyNode(
+                "Version", int32_t(101), outstream, binary, indent
+            );
+            FBX::Node::WritePropertyNode(
+                "Name", "", outstream, binary, indent
+            );
+            FBX::Node::WritePropertyNode(
+                "MappingInformationType", "ByPolygonVertex",
+                outstream, binary, indent
+            );
+            // TODO: vertex-normals or indexed normals when appropriate
+            FBX::Node::WritePropertyNode(
+                "ReferenceInformationType", "Direct",
+                outstream, binary, indent
+            );
+            std::vector<double> normal_data;
+            normal_data.reserve(3 * polygon_data.size());
+            for (size_t fi = 0; fi < m->mNumFaces; ++fi) {
+                const aiFace &f = m->mFaces[fi];
+                for (size_t pvi = 0; pvi < f.mNumIndices; ++pvi) {
+                    const aiVector3D &n = m->mNormals[f.mIndices[pvi]];
+                    normal_data.push_back(n.x);
+                    normal_data.push_back(n.y);
+                    normal_data.push_back(n.z);
+                }
+            }
+            FBX::Node::WritePropertyNode(
+                "Normals", normal_data, outstream, binary, indent
+            );
+            // note: version 102 has a NormalsW also... not sure what it is,
+            // so we can stick with version 101 for now.
+            indent = 2;
+            normals.End(outstream, binary, indent, true);
+        }
+
+        // uvs, if any
+        for (size_t uvi = 0; uvi < m->GetNumUVChannels(); ++uvi) {
+            if (m->mNumUVComponents[uvi] > 2) {
+                // FBX only supports 2-channel UV maps...
+                // or at least i'm not sure how to indicate a different number
+                std::stringstream err;
+                err << "Only 2-channel UV maps supported by FBX,";
+                err << " but mesh " << mi;
+                if (m->mName.length) {
+                    err << " (" << m->mName.C_Str() << ")";
+                }
+                err << " UV map " << uvi;
+                err << " has " << m->mNumUVComponents[uvi];
+                err << " components! Data will be preserved,";
+                err << " but may be incorrectly interpreted on load.";
+                ASSIMP_LOG_WARN(err.str());
+            }
+            FBX::Node uv("LayerElementUV", int32_t(uvi));
+            uv.Begin(outstream, binary, indent);
+            uv.DumpProperties(outstream, binary, indent);
+            uv.EndProperties(outstream, binary, indent);
+            uv.BeginChildren(outstream, binary, indent);
+            indent = 3;
+            FBX::Node::WritePropertyNode(
+                "Version", int32_t(101), outstream, binary, indent
+            );
+            // it doesn't seem like assimp keeps the uv map name,
+            // so just leave it blank.
+            FBX::Node::WritePropertyNode(
+                "Name", "", outstream, binary, indent
+            );
+            FBX::Node::WritePropertyNode(
+                "MappingInformationType", "ByPolygonVertex",
+                outstream, binary, indent
+            );
+            FBX::Node::WritePropertyNode(
+                "ReferenceInformationType", "IndexToDirect",
+                outstream, binary, indent
+            );
+
+            std::vector<double> uv_data;
+            std::vector<int32_t> uv_indices;
+            std::map<aiVector3D,int32_t> index_by_uv;
+            int32_t index = 0;
+            for (size_t fi = 0; fi < m->mNumFaces; ++fi) {
+                const aiFace &f = m->mFaces[fi];
+                for (size_t pvi = 0; pvi < f.mNumIndices; ++pvi) {
+                    const aiVector3D &uv =
+                        m->mTextureCoords[uvi][f.mIndices[pvi]];
+                    auto elem = index_by_uv.find(uv);
+                    if (elem == index_by_uv.end()) {
+                        index_by_uv[uv] = index;
+                        uv_indices.push_back(index);
+                        for (unsigned int x = 0; x < m->mNumUVComponents[uvi]; ++x) {
+                            uv_data.push_back(uv[x]);
+                        }
+                        ++index;
+                    } else {
+                        uv_indices.push_back(elem->second);
+                    }
+                }
+            }
+            FBX::Node::WritePropertyNode(
+                "UV", uv_data, outstream, binary, indent
+            );
+            FBX::Node::WritePropertyNode(
+                "UVIndex", uv_indices, outstream, binary, indent
+            );
+            indent = 2;
+            uv.End(outstream, binary, indent, true);
+        }
+
+        // i'm not really sure why this material section exists,
+        // as the material is linked via "Connections".
+        // it seems to always have the same "0" value.
+        FBX::Node mat("LayerElementMaterial", int32_t(0));
+        mat.AddChild("Version", int32_t(101));
+        mat.AddChild("Name", "");
+        mat.AddChild("MappingInformationType", "AllSame");
+        mat.AddChild("ReferenceInformationType", "IndexToDirect");
+        std::vector<int32_t> mat_indices = {0};
+        mat.AddChild("Materials", mat_indices);
+        mat.Dump(outstream, binary, indent);
+
+        // finally we have the layer specifications,
+        // which select the normals / UV set / etc to use.
+        // TODO: handle multiple uv sets correctly?
+        FBX::Node layer("Layer", int32_t(0));
+        layer.AddChild("Version", int32_t(100));
+        FBX::Node le("LayerElement");
+        le.AddChild("Type", "LayerElementNormal");
+        le.AddChild("TypedIndex", int32_t(0));
+        layer.AddChild(le);
+        le = FBX::Node("LayerElement");
+        le.AddChild("Type", "LayerElementMaterial");
+        le.AddChild("TypedIndex", int32_t(0));
+        layer.AddChild(le);
+        le = FBX::Node("LayerElement");
+        le.AddChild("Type", "LayerElementUV");
+        le.AddChild("TypedIndex", int32_t(0));
+        layer.AddChild(le);
+        layer.Dump(outstream, binary, indent);
+
+        for(unsigned int lr = 1; lr < m->GetNumUVChannels(); ++ lr)
+        {
+            FBX::Node layerExtra("Layer", int32_t(1));
+            layerExtra.AddChild("Version", int32_t(100));
+            FBX::Node leExtra("LayerElement");
+            leExtra.AddChild("Type", "LayerElementUV");
+            leExtra.AddChild("TypedIndex", int32_t(lr));
+            layerExtra.AddChild(leExtra);
+            layerExtra.Dump(outstream, binary, indent);
+        }
+        // finish the node record
+        indent = 1;
+        n.End(outstream, binary, indent, true);
+    }
+
+    // aiMaterial
+    material_uids.clear();
+    for (size_t i = 0; i < mScene->mNumMaterials; ++i) {
+        // it's all about this material
+        aiMaterial* m = mScene->mMaterials[i];
+
+        // these are used to receive material data
+        float f; aiColor3D c;
+
+        // start the node record
+        FBX::Node n("Material");
+
+        int64_t uid = generate_uid();
+        material_uids.push_back(uid);
+        n.AddProperty(uid);
+
+        aiString name;
+        m->Get(AI_MATKEY_NAME, name);
+        n.AddProperty(name.C_Str() + FBX::SEPARATOR + "Material");
+
+        n.AddProperty("");
+
+        n.AddChild("Version", int32_t(102));
+        f = 0;
+        m->Get(AI_MATKEY_SHININESS, f);
+        bool phong = (f > 0);
+        if (phong) {
+            n.AddChild("ShadingModel", "phong");
+        } else {
+            n.AddChild("ShadingModel", "lambert");
+        }
+        n.AddChild("MultiLayer", int32_t(0));
+
+        FBX::Node p("Properties70");
+
+        // materials exported using the FBX SDK have two sets of fields.
+        // there are the properties specified in the PropertyTemplate,
+        // which are those supported by the modernFBX SDK,
+        // and an extra set of properties with simpler names.
+        // The extra properties are a legacy material system from pre-2009.
+        //
+        // In the modern system, each property has "color" and "factor".
+        // Generally the interpretation of these seems to be
+        // that the colour is multiplied by the factor before use,
+        // but this is not always clear-cut.
+        //
+        // Usually assimp only stores the colour,
+        // so we can just leave the factors at the default "1.0".
+
+        // first we can export the "standard" properties
+        if (m->Get(AI_MATKEY_COLOR_AMBIENT, c) == aiReturn_SUCCESS) {
+            p.AddP70colorA("AmbientColor", c.r, c.g, c.b);
+            //p.AddP70numberA("AmbientFactor", 1.0);
+        }
+        if (m->Get(AI_MATKEY_COLOR_DIFFUSE, c) == aiReturn_SUCCESS) {
+            p.AddP70colorA("DiffuseColor", c.r, c.g, c.b);
+            //p.AddP70numberA("DiffuseFactor", 1.0);
+        }
+        if (m->Get(AI_MATKEY_COLOR_TRANSPARENT, c) == aiReturn_SUCCESS) {
+            // "TransparentColor" / "TransparencyFactor"...
+            // thanks FBX, for your insightful interpretation of consistency
+            p.AddP70colorA("TransparentColor", c.r, c.g, c.b);
+            // TransparencyFactor defaults to 0.0, so set it to 1.0.
+            // note: Maya always sets this to 1.0,
+            // so we can't use it sensibly as "Opacity".
+            // In stead we rely on the legacy "Opacity" value, below.
+            // Blender also relies on "Opacity" not "TransparencyFactor",
+            // probably for a similar reason.
+            p.AddP70numberA("TransparencyFactor", 1.0);
+        }
+        if (m->Get(AI_MATKEY_COLOR_REFLECTIVE, c) == aiReturn_SUCCESS) {
+            p.AddP70colorA("ReflectionColor", c.r, c.g, c.b);
+        }
+        if (m->Get(AI_MATKEY_REFLECTIVITY, f) == aiReturn_SUCCESS) {
+            p.AddP70numberA("ReflectionFactor", f);
+        }
+        if (phong) {
+            if (m->Get(AI_MATKEY_COLOR_SPECULAR, c) == aiReturn_SUCCESS) {
+                p.AddP70colorA("SpecularColor", c.r, c.g, c.b);
+            }
+            if (m->Get(AI_MATKEY_SHININESS_STRENGTH, f) == aiReturn_SUCCESS) {
+                p.AddP70numberA("ShininessFactor", f);
+            }
+            if (m->Get(AI_MATKEY_SHININESS, f) == aiReturn_SUCCESS) {
+                p.AddP70numberA("ShininessExponent", f);
+            }
+            if (m->Get(AI_MATKEY_REFLECTIVITY, f) == aiReturn_SUCCESS) {
+                p.AddP70numberA("ReflectionFactor", f);
+            }
+        }
+
+        // Now the legacy system.
+        // For safety let's include it.
+        // thrse values don't exist in the property template,
+        // and usually are completely ignored when loading.
+        // One notable exception is the "Opacity" property,
+        // which Blender uses as (1.0 - alpha).
+        c.r = 0.0f; c.g = 0.0f; c.b = 0.0f;
+        m->Get(AI_MATKEY_COLOR_EMISSIVE, c);
+        p.AddP70vector("Emissive", c.r, c.g, c.b);
+        c.r = 0.2f; c.g = 0.2f; c.b = 0.2f;
+        m->Get(AI_MATKEY_COLOR_AMBIENT, c);
+        p.AddP70vector("Ambient", c.r, c.g, c.b);
+        c.r = 0.8f; c.g = 0.8f; c.b = 0.8f;
+        m->Get(AI_MATKEY_COLOR_DIFFUSE, c);
+        p.AddP70vector("Diffuse", c.r, c.g, c.b);
+        // The FBX SDK determines "Opacity" from transparency colour (RGB)
+        // and factor (F) as: O = (1.0 - F * ((R + G + B) / 3)).
+        // However we actually have an opacity value,
+        // so we should take it from AI_MATKEY_OPACITY if possible.
+        // It might make more sense to use TransparencyFactor,
+        // but Blender actually loads "Opacity" correctly, so let's use it.
+        f = 1.0f;
+        if (m->Get(AI_MATKEY_COLOR_TRANSPARENT, c) == aiReturn_SUCCESS) {
+            f = 1.0f - ((c.r + c.g + c.b) / 3.0f);
+        }
+        m->Get(AI_MATKEY_OPACITY, f);
+        p.AddP70double("Opacity", f);
+        if (phong) {
+            // specular color is multiplied by shininess_strength
+            c.r = 0.2f; c.g = 0.2f; c.b = 0.2f;
+            m->Get(AI_MATKEY_COLOR_SPECULAR, c);
+            f = 1.0f;
+            m->Get(AI_MATKEY_SHININESS_STRENGTH, f);
+            p.AddP70vector("Specular", f*c.r, f*c.g, f*c.b);
+            f = 20.0f;
+            m->Get(AI_MATKEY_SHININESS, f);
+            p.AddP70double("Shininess", f);
+            // Legacy "Reflectivity" is F*F*((R+G+B)/3),
+            // where F is the proportion of light reflected (AKA reflectivity),
+            // and RGB is the reflective colour of the material.
+            // No idea why, but we might as well set it the same way.
+            f = 0.0f;
+            m->Get(AI_MATKEY_REFLECTIVITY, f);
+            c.r = 1.0f, c.g = 1.0f, c.b = 1.0f;
+            m->Get(AI_MATKEY_COLOR_REFLECTIVE, c);
+            p.AddP70double("Reflectivity", f*f*((c.r+c.g+c.b)/3.0));
+        }
+
+        n.AddChild(p);
+
+        n.Dump(outstream, binary, indent);
+    }
+
+    // we need to look up all the images we're using,
+    // so we can generate uids, and eliminate duplicates.
+    std::map<std::string, int64_t> uid_by_image;
+    for (size_t i = 0; i < mScene->mNumMaterials; ++i) {
+        aiString texpath;
+        aiMaterial* mat = mScene->mMaterials[i];
+        for (
+            size_t tt = aiTextureType_DIFFUSE;
+            tt < aiTextureType_UNKNOWN;
+            ++tt
+        ){
+            const aiTextureType textype = static_cast<aiTextureType>(tt);
+            const size_t texcount = mat->GetTextureCount(textype);
+            for (size_t j = 0; j < texcount; ++j) {
+                mat->GetTexture(textype, (unsigned int)j, &texpath);
+                const std::string texstring = texpath.C_Str();
+                auto elem = uid_by_image.find(texstring);
+                if (elem == uid_by_image.end()) {
+                    uid_by_image[texstring] = generate_uid();
+                }
+            }
+        }
+    }
+
+    // FbxVideo - stores images used by textures.
+    for (const auto &it : uid_by_image) {
+        FBX::Node n("Video");
+        const int64_t& uid = it.second;
+        const std::string name = ""; // TODO: ... name???
+        n.AddProperties(uid, name + FBX::SEPARATOR + "Video", "Clip");
+        n.AddChild("Type", "Clip");
+        FBX::Node p("Properties70");
+        // TODO: get full path... relative path... etc... ugh...
+        // for now just use the same path for everything,
+        // and hopefully one of them will work out.
+        std::string path = it.first;
+        // try get embedded texture
+        const aiTexture* embedded_texture = mScene->GetEmbeddedTexture(it.first.c_str());
+        if (embedded_texture != nullptr) {
+            // change the path (use original filename, if available. If name is empty, concatenate texture index with file extension)
+            std::stringstream newPath;
+            if (embedded_texture->mFilename.length > 0) {
+                newPath << embedded_texture->mFilename.C_Str();
+            } else if (embedded_texture->achFormatHint[0]) {
+                int texture_index = std::stoi(path.substr(1, path.size() - 1));
+                newPath << texture_index << "." << embedded_texture->achFormatHint;
+            }
+            path = newPath.str();
+            // embed the texture
+            size_t texture_size = static_cast<size_t>(embedded_texture->mWidth * std::max(embedded_texture->mHeight, 1u));
+            if (binary) {
+                // embed texture as binary data
+                std::vector<uint8_t> tex_data;
+                tex_data.resize(texture_size);
+                memcpy(&tex_data[0], (char*)embedded_texture->pcData, texture_size);
+                n.AddChild("Content", tex_data);
+            } else {
+                // embed texture in base64 encoding
+                std::string encoded_texture = FBX::Util::EncodeBase64((char*)embedded_texture->pcData, texture_size);
+                n.AddChild("Content", encoded_texture);
+            }
+        }
+        p.AddP70("Path", "KString", "XRefUrl", "", path);
+        n.AddChild(p);
+        n.AddChild("UseMipMap", int32_t(0));
+        n.AddChild("Filename", path);
+        n.AddChild("RelativeFilename", path);
+        n.Dump(outstream, binary, indent);
+    }
+
+    // Textures
+    // referenced by material_index/texture_type pairs.
+    std::map<std::pair<size_t,size_t>,int64_t> texture_uids;
+    const std::map<aiTextureType,std::string> prop_name_by_tt = {
+        {aiTextureType_DIFFUSE,      "DiffuseColor"},
+        {aiTextureType_SPECULAR,     "SpecularColor"},
+        {aiTextureType_AMBIENT,      "AmbientColor"},
+        {aiTextureType_EMISSIVE,     "EmissiveColor"},
+        {aiTextureType_HEIGHT,       "Bump"},
+        {aiTextureType_NORMALS,      "NormalMap"},
+        {aiTextureType_SHININESS,    "ShininessExponent"},
+        {aiTextureType_OPACITY,      "TransparentColor"},
+        {aiTextureType_DISPLACEMENT, "DisplacementColor"},
+        //{aiTextureType_LIGHTMAP, "???"},
+        {aiTextureType_REFLECTION,   "ReflectionColor"}
+        //{aiTextureType_UNKNOWN, ""}
+    };
+    for (size_t i = 0; i < mScene->mNumMaterials; ++i) {
+        // textures are attached to materials
+        aiMaterial* mat = mScene->mMaterials[i];
+        int64_t material_uid = material_uids[i];
+
+        for (
+            size_t j = aiTextureType_DIFFUSE;
+            j < aiTextureType_UNKNOWN;
+            ++j
+        ) {
+            const aiTextureType tt = static_cast<aiTextureType>(j);
+            size_t n = mat->GetTextureCount(tt);
+
+            if (n < 1) { // no texture of this type
+                continue;
+            }
+
+            if (n > 1) {
+                // TODO: multilayer textures
+                std::stringstream err;
+                err << "Multilayer textures not supported (for now),";
+                err << " skipping texture type " << j;
+                err << " of material " << i;
+                ASSIMP_LOG_WARN(err.str());
+            }
+
+            // get image path for this (single-image) texture
+            aiString tpath;
+            if (mat->GetTexture(tt, 0, &tpath) != aiReturn_SUCCESS) {
+                std::stringstream err;
+                err << "Failed to get texture 0 for texture of type " << tt;
+                err << " on material " << i;
+                err << ", however GetTextureCount returned 1.";
+                throw DeadlyExportError(err.str());
+            }
+            const std::string texture_path(tpath.C_Str());
+
+            // get connected image uid
+            auto elem = uid_by_image.find(texture_path);
+            if (elem == uid_by_image.end()) {
+                // this should never happen
+                std::stringstream err;
+                err << "Failed to find video element for texture with path";
+                err << " \"" << texture_path << "\"";
+                err << ", type " << j << ", material " << i;
+                throw DeadlyExportError(err.str());
+            }
+            const int64_t image_uid = elem->second;
+
+            // get the name of the material property to connect to
+            auto elem2 = prop_name_by_tt.find(tt);
+            if (elem2 == prop_name_by_tt.end()) {
+                // don't know how to handle this type of texture,
+                // so skip it.
+                std::stringstream err;
+                err << "Not sure how to handle texture of type " << j;
+                err << " on material " << i;
+                err << ", skipping...";
+                ASSIMP_LOG_WARN(err.str());
+                continue;
+            }
+            const std::string& prop_name = elem2->second;
+
+            // generate a uid for this texture
+            const int64_t texture_uid = generate_uid();
+
+            // link the texture to the material
+            connections.emplace_back(
+                "C", "OP", texture_uid, material_uid, prop_name
+            );
+
+            // link the image data to the texture
+            connections.emplace_back("C", "OO", image_uid, texture_uid);
+
+            // now write the actual texture node
+            FBX::Node tnode("Texture");
+            // TODO: some way to determine texture name?
+            const std::string texture_name = "" + FBX::SEPARATOR + "Texture";
+            tnode.AddProperties(texture_uid, texture_name, "");
+            // there really doesn't seem to be a better type than this:
+            tnode.AddChild("Type", "TextureVideoClip");
+            tnode.AddChild("Version", int32_t(202));
+            tnode.AddChild("TextureName", texture_name);
+            FBX::Node p("Properties70");
+            p.AddP70enum("CurrentTextureBlendMode", 0); // TODO: verify
+            //p.AddP70string("UVSet", ""); // TODO: how should this work?
+            p.AddP70bool("UseMaterial", 1);
+            tnode.AddChild(p);
+            // can't easily detrmine which texture path will be correct,
+            // so just store what we have in every field.
+            // these being incorrect is a common problem with FBX anyway.
+            tnode.AddChild("FileName", texture_path);
+            tnode.AddChild("RelativeFilename", texture_path);
+            tnode.AddChild("ModelUVTranslation", double(0.0), double(0.0));
+            tnode.AddChild("ModelUVScaling", double(1.0), double(1.0));
+            tnode.AddChild("Texture_Alpha_Source", "None");
+            tnode.AddChild(
+                "Cropping", int32_t(0), int32_t(0), int32_t(0), int32_t(0)
+            );
+            tnode.Dump(outstream, binary, indent);
+        }
+    }
+
+    // bones.
+    //
+    // output structure:
+    // subset of node hierarchy that are "skeleton",
+    // i.e. do not have meshes but only bones.
+    // but.. i'm not sure how anyone could guarantee that...
+    //
+    // input...
+    // well, for each mesh it has "bones",
+    // and the bone names correspond to nodes.
+    // of course we also need the parent nodes,
+    // as they give some of the transform........
+    //
+    // well. we can assume a sane input, i suppose.
+    //
+    // so input is the bone node hierarchy,
+    // with an extra thing for the transformation of the MESH in BONE space.
+    //
+    // output is a set of bone nodes,
+    // a "bindpose" which indicates the default local transform of all bones,
+    // and a set of "deformers".
+    // each deformer is parented to a mesh geometry,
+    // and has one or more "subdeformer"s as children.
+    // each subdeformer has one bone node as a child,
+    // and represents the influence of that bone on the grandparent mesh.
+    // the subdeformer has a list of indices, and weights,
+    // with indices specifying vertex indices,
+    // and weights specifying the corresponding influence of this bone.
+    // it also has Transform and TransformLink elements,
+    // specifying the transform of the MESH in BONE space,
+    // and the transformation of the BONE in WORLD space,
+    // likely in the bindpose.
+    //
+    // the input bone structure is different but similar,
+    // storing the number of weights for this bone,
+    // and an array of (vertex index, weight) pairs.
+    //
+    // one sticky point is that the number of vertices may not match,
+    // because assimp splits vertices by normal, uv, etc.
+
+    // functor for aiNode sorting
+    struct SortNodeByName
+    {
+        bool operator()(const aiNode *lhs, const aiNode *rhs) const
+        {
+            return strcmp(lhs->mName.C_Str(), rhs->mName.C_Str()) < 0;
+        }
+    };
+
+    // first we should mark the skeleton for each mesh.
+    // the skeleton must include not only the aiBones,
+    // but also all their parent nodes.
+    // anything that affects the position of any bone node must be included.
+    // Use SorNodeByName to make sure the exported result will be the same across all systems
+    // Otherwise the aiNodes of the skeleton would be sorted based on the pointer address, which isn't consistent
+    std::vector<std::set<const aiNode*, SortNodeByName>> skeleton_by_mesh(mScene->mNumMeshes);
+    // at the same time we can build a list of all the skeleton nodes,
+    // which will be used later to mark them as type "limbNode".
+    std::unordered_set<const aiNode*> limbnodes;
+    
+    //actual bone nodes in fbx, without parenting-up
+    std::unordered_set<std::string> setAllBoneNamesInScene;
+    for(unsigned int m = 0; m < mScene->mNumMeshes; ++ m)
+    {
+        aiMesh* pMesh = mScene->mMeshes[m];
+        for(unsigned int b = 0; b < pMesh->mNumBones; ++ b)
+            setAllBoneNamesInScene.insert(pMesh->mBones[b]->mName.data);
+    }
+    aiMatrix4x4 mxTransIdentity;
+    
+    // and a map of nodes by bone name, as finding them is annoying.
+    std::map<std::string,aiNode*> node_by_bone;
+    for (size_t mi = 0; mi < mScene->mNumMeshes; ++mi) {
+        const aiMesh* m = mScene->mMeshes[mi];
+        std::set<const aiNode*, SortNodeByName> skeleton;
+        for (size_t bi =0; bi < m->mNumBones; ++bi) {
+            const aiBone* b = m->mBones[bi];
+            const std::string name(b->mName.C_Str());
+            auto elem = node_by_bone.find(name);
+            aiNode* n;
+            if (elem != node_by_bone.end()) {
+                n = elem->second;
+            } else {
+                n = mScene->mRootNode->FindNode(b->mName);
+                if (!n) {
+                    // this should never happen
+                    std::stringstream err;
+                    err << "Failed to find node for bone: \"" << name << "\"";
+                    throw DeadlyExportError(err.str());
+                }
+                node_by_bone[name] = n;
+                limbnodes.insert(n);
+            }
+            skeleton.insert(n);
+            // mark all parent nodes as skeleton as well,
+            // up until we find the root node,
+            // or else the node containing the mesh,
+            // or else the parent of a node containig the mesh.
+            for (
+                const aiNode* parent = n->mParent;
+                parent && parent != mScene->mRootNode;
+                parent = parent->mParent
+            ) {
+                // if we've already done this node we can skip it all
+                if (skeleton.count(parent)) {
+                    break;
+                }
+                // ignore fbx transform nodes as these will be collapsed later
+                // TODO: cache this by aiNode*
+                const std::string node_name(parent->mName.C_Str());
+                if (node_name.find(MAGIC_NODE_TAG) != std::string::npos) {
+                    continue;
+                }
+                //not a bone in scene && no effect in transform
+                if(setAllBoneNamesInScene.find(node_name)==setAllBoneNamesInScene.end()
+                   && parent->mTransformation == mxTransIdentity) {
+                        continue;
+                }
+                // otherwise check if this is the root of the skeleton
+                bool end = false;
+                // is the mesh part of this node?
+                for (size_t i = 0; i < parent->mNumMeshes; ++i) {
+                    if (parent->mMeshes[i] == mi) {
+                        end = true;
+                        break;
+                    }
+                }
+                // is the mesh in one of the children of this node?
+                for (size_t j = 0; j < parent->mNumChildren; ++j) {
+                    aiNode* child = parent->mChildren[j];
+                    for (size_t i = 0; i < child->mNumMeshes; ++i) {
+                        if (child->mMeshes[i] == mi) {
+                            end = true;
+                            break;
+                        }
+                    }
+                    if (end) { break; }
+                }
+                limbnodes.insert(parent);
+                skeleton.insert(parent);
+                // if it was the skeleton root we can finish here
+                if (end) { break; }
+            }
+        }
+        skeleton_by_mesh[mi] = skeleton;
+    }
+
+    // we'll need the uids for the bone nodes, so generate them now
+    for (size_t i = 0; i < mScene->mNumMeshes; ++i) {
+        auto &s = skeleton_by_mesh[i];
+        for (const aiNode* n : s) {
+            auto elem = node_uids.find(n);
+            if (elem == node_uids.end()) {
+                node_uids[n] = generate_uid();
+            }
+        }
+    }
+
+    // now, for each aiMesh, we need to export a deformer,
+    // and for each aiBone a subdeformer,
+    // which should have all the skinning info.
+    // these will need to be connected properly to the mesh,
+    // and we can do that all now.
+    for (size_t mi = 0; mi < mScene->mNumMeshes; ++mi) {
+        const aiMesh* m = mScene->mMeshes[mi];
+        if (!m->HasBones()) {
+            continue;
+        }
+        // make a deformer for this mesh
+        int64_t deformer_uid = generate_uid();
+        FBX::Node dnode("Deformer");
+        dnode.AddProperties(deformer_uid, FBX::SEPARATOR + "Deformer", "Skin");
+        dnode.AddChild("Version", int32_t(101));
+        // "acuracy"... this is not a typo....
+        dnode.AddChild("Link_DeformAcuracy", double(50));
+        dnode.AddChild("SkinningType", "Linear"); // TODO: other modes?
+        dnode.Dump(outstream, binary, indent);
+
+        // connect it
+        connections.emplace_back("C", "OO", deformer_uid, mesh_uids[mi]);
+
+        // we will be indexing by vertex...
+        // but there might be a different number of "vertices"
+        // between assimp and our output FBX.
+        // this code is cut-and-pasted from the geometry section above...
+        // ideally this should not be so.
+        // ---
+        // index of original vertex in vertex data vector
+        std::vector<int32_t> vertex_indices;
+        // map of vertex value to its index in the data vector
+        std::map<aiVector3D,size_t> index_by_vertex_value;
+        int32_t index = 0;
+        for (size_t vi = 0; vi < m->mNumVertices; ++vi) {
+            aiVector3D vtx = m->mVertices[vi];
+            auto elem = index_by_vertex_value.find(vtx);
+            if (elem == index_by_vertex_value.end()) {
+                vertex_indices.push_back(index);
+                index_by_vertex_value[vtx] = index;
+                ++index;
+            } else {
+                vertex_indices.push_back(int32_t(elem->second));
+            }
+        }
+
+        // TODO, FIXME: this won't work if anything is not in the bind pose.
+        // for now if such a situation is detected, we throw an exception.
+        std::set<const aiBone*> not_in_bind_pose;
+        std::set<const aiNode*> no_offset_matrix;
+
+        // first get this mesh's position in world space,
+        // as we'll need it for each subdeformer.
+        //
+        // ...of course taking the position of the MESH doesn't make sense,
+        // as it can be instanced to many nodes.
+        // All we can do is assume no instancing,
+        // and take the first node we find that contains the mesh.
+        aiNode* mesh_node = get_node_for_mesh((unsigned int)mi, mScene->mRootNode);
+        aiMatrix4x4 mesh_xform = get_world_transform(mesh_node, mScene);
+
+        // now make a subdeformer for each bone in the skeleton
+        const std::set<const aiNode*, SortNodeByName> skeleton= skeleton_by_mesh[mi];
+        for (const aiNode* bone_node : skeleton) {
+            // if there's a bone for this node, find it
+            const aiBone* b = nullptr;
+            for (size_t bi = 0; bi < m->mNumBones; ++bi) {
+                // TODO: this probably should index by something else
+                const std::string name(m->mBones[bi]->mName.C_Str());
+                if (node_by_bone[name] == bone_node) {
+                    b = m->mBones[bi];
+                    break;
+                }
+            }
+            if (!b) {
+                no_offset_matrix.insert(bone_node);
+            }
+
+            // start the subdeformer node
+            const int64_t subdeformer_uid = generate_uid();
+            FBX::Node sdnode("Deformer");
+            sdnode.AddProperties(
+                subdeformer_uid, FBX::SEPARATOR + "SubDeformer", "Cluster"
+            );
+            sdnode.AddChild("Version", int32_t(100));
+            sdnode.AddChild("UserData", "", "");
+
+            // add indices and weights, if any
+            if (b) {
+                std::vector<int32_t> subdef_indices;
+                std::vector<double> subdef_weights;
+                int32_t last_index = -1;
+                for (size_t wi = 0; wi < b->mNumWeights; ++wi) {
+                    int32_t vi = vertex_indices[b->mWeights[wi].mVertexId];
+                    if (vi == last_index) {
+                        // only for vertices we exported to fbx
+                        // TODO, FIXME: this assumes identically-located vertices
+                        // will always deform in the same way.
+                        // as assimp doesn't store a separate list of "positions",
+                        // there's not much that can be done about this
+                        // other than assuming that identical position means
+                        // identical vertex.
+                        continue;
+                    }
+                    subdef_indices.push_back(vi);
+                    subdef_weights.push_back(b->mWeights[wi].mWeight);
+                    last_index = vi;
+                }
+                // yes, "indexes"
+                sdnode.AddChild("Indexes", subdef_indices);
+                sdnode.AddChild("Weights", subdef_weights);
+            }
+
+            // transform is the transform of the mesh, but in bone space.
+            // if the skeleton is in the bind pose,
+            // we can take the inverse of the world-space bone transform
+            // and multiply by the world-space transform of the mesh.
+            aiMatrix4x4 bone_xform = get_world_transform(bone_node, mScene);
+            aiMatrix4x4 inverse_bone_xform = bone_xform;
+            inverse_bone_xform.Inverse();
+            aiMatrix4x4 tr = inverse_bone_xform * mesh_xform;
+
+            // this should be the same as the bone's mOffsetMatrix.
+            // if it's not the same, the skeleton isn't in the bind pose.
+            float epsilon = 1e-4f; // some error is to be expected
+            float epsilon_custom = mProperties->GetPropertyFloat("BINDPOSE_EPSILON", -1);
+            if(epsilon_custom > 0)
+                epsilon = epsilon_custom;
+            bool bone_xform_okay = true;
+            if (b && ! tr.Equal(b->mOffsetMatrix, epsilon)) {
+                not_in_bind_pose.insert(b);
+                bone_xform_okay = false;
+            }
+
+            // if we have a bone we should use the mOffsetMatrix,
+            // otherwise try to just use the calculated transform.
+            if (b) {
+                sdnode.AddChild("Transform", b->mOffsetMatrix);
+            } else {
+                sdnode.AddChild("Transform", tr);
+            }
+            // note: it doesn't matter if we mix these,
+            // because if they disagree we'll throw an exception later.
+            // it could be that the skeleton is not in the bone pose
+            // but all bones are still defined,
+            // in which case this would use the mOffsetMatrix for everything
+            // and a correct skeleton would still be output.
+
+            // transformlink should be the position of the bone in world space.
+            // if the bone is in the bind pose (or nonexistent),
+            // we can just use the matrix we already calculated
+            if (bone_xform_okay) {
+                sdnode.AddChild("TransformLink", bone_xform);
+            // otherwise we can only work it out using the mesh position.
+            } else {
+                aiMatrix4x4 trl = b->mOffsetMatrix;
+                trl.Inverse();
+                trl *= mesh_xform;
+                sdnode.AddChild("TransformLink", trl);
+            }
+            // note: this means we ALWAYS rely on the mesh node transform
+            // being unchanged from the time the skeleton was bound.
+            // there's not really any way around this at the moment.
+
+            // done
+            sdnode.Dump(outstream, binary, indent);
+
+            // lastly, connect to the parent deformer
+            connections.emplace_back(
+                "C", "OO", subdeformer_uid, deformer_uid
+            );
+
+            // we also need to connect the limb node to the subdeformer.
+            connections.emplace_back(
+                "C", "OO", node_uids[bone_node], subdeformer_uid
+            );
+        }
+
+        // if we cannot create a valid FBX file, simply die.
+        // this will both prevent unnecessary bug reports,
+        // and tell the user what they can do to fix the situation
+        // (i.e. export their model in the bind pose).
+        if (no_offset_matrix.size() && not_in_bind_pose.size()) {
+            std::stringstream err;
+            err << "Not enough information to construct bind pose";
+            err << " for mesh " << mi << "!";
+            err << " Transform matrix for bone \"";
+            err << (*not_in_bind_pose.begin())->mName.C_Str() << "\"";
+            if (not_in_bind_pose.size() > 1) {
+                err << " (and " << not_in_bind_pose.size() - 1 << " more)";
+            }
+            err << " does not match mOffsetMatrix,";
+            err << " and node \"";
+            err << (*no_offset_matrix.begin())->mName.C_Str() << "\"";
+            if (no_offset_matrix.size() > 1) {
+                err << " (and " << no_offset_matrix.size() - 1 << " more)";
+            }
+            err << " has no offset matrix to rely on.";
+            err << " Please ensure bones are in the bind pose to export.";
+            throw DeadlyExportError(err.str());
+        }
+
+    }
+
+    // BindPose
+    //
+    // This is a legacy system, which should be unnecessary.
+    //
+    // Somehow including it slows file loading by the official FBX SDK,
+    // and as it can reconstruct it from the deformers anyway,
+    // this is not currently included.
+    //
+    // The code is kept here in case it's useful in the future,
+    // but it's pretty much a hack anyway,
+    // as assimp doesn't store bindpose information for full skeletons.
+    //
+    /*for (size_t mi = 0; mi < mScene->mNumMeshes; ++mi) {
+        aiMesh* mesh = mScene->mMeshes[mi];
+        if (! mesh->HasBones()) { continue; }
+        int64_t bindpose_uid = generate_uid();
+        FBX::Node bpnode("Pose");
+        bpnode.AddProperty(bindpose_uid);
+        // note: this uid is never linked or connected to anything.
+        bpnode.AddProperty(FBX::SEPARATOR + "Pose"); // blank name
+        bpnode.AddProperty("BindPose");
+
+        bpnode.AddChild("Type", "BindPose");
+        bpnode.AddChild("Version", int32_t(100));
+
+        aiNode* mesh_node = get_node_for_mesh(mi, mScene->mRootNode);
+
+        // next get the whole skeleton for this mesh.
+        // we need it all to define the bindpose section.
+        // the FBX SDK will complain if it's missing,
+        // and also if parents of used bones don't have a subdeformer.
+        // order shouldn't matter.
+        std::set<aiNode*> skeleton;
+        for (size_t bi = 0; bi < mesh->mNumBones; ++bi) {
+            // bone node should have already been indexed
+            const aiBone* b = mesh->mBones[bi];
+            const std::string bone_name(b->mName.C_Str());
+            aiNode* parent = node_by_bone[bone_name];
+            // insert all nodes down to the root or mesh node
+            while (
+                parent
+                && parent != mScene->mRootNode
+                && parent != mesh_node
+            ) {
+                skeleton.insert(parent);
+                parent = parent->mParent;
+            }
+        }
+
+        // number of pose nodes. includes one for the mesh itself.
+        bpnode.AddChild("NbPoseNodes", int32_t(1 + skeleton.size()));
+
+        // the first pose node is always the mesh itself
+        FBX::Node pose("PoseNode");
+        pose.AddChild("Node", mesh_uids[mi]);
+        aiMatrix4x4 mesh_node_xform = get_world_transform(mesh_node, mScene);
+        pose.AddChild("Matrix", mesh_node_xform);
+        bpnode.AddChild(pose);
+
+        for (aiNode* bonenode : skeleton) {
+            // does this node have a uid yet?
+            int64_t node_uid;
+            auto node_uid_iter = node_uids.find(bonenode);
+            if (node_uid_iter != node_uids.end()) {
+                node_uid = node_uid_iter->second;
+            } else {
+                node_uid = generate_uid();
+                node_uids[bonenode] = node_uid;
+            }
+
+            // make a pose thingy
+            pose = FBX::Node("PoseNode");
+            pose.AddChild("Node", node_uid);
+            aiMatrix4x4 node_xform = get_world_transform(bonenode, mScene);
+            pose.AddChild("Matrix", node_xform);
+            bpnode.AddChild(pose);
+        }
+
+        // now write it
+        bpnode.Dump(outstream, binary, indent);
+    }*/
+
+    // TODO: cameras, lights
+
+    // write nodes (i.e. model hierarchy)
+    // start at root node
+    WriteModelNodes(
+        outstream, mScene->mRootNode, 0, limbnodes
+    );
+
+    // animations
+    //
+    // in FBX there are:
+    // * AnimationStack - corresponds to an aiAnimation
+    // * AnimationLayer - a combinable animation component
+    // * AnimationCurveNode - links the property to be animated
+    // * AnimationCurve - defines animation data for a single property value
+    //
+    // the CurveNode also provides the default value for a property,
+    // such as the X, Y, Z coordinates for animatable translation.
+    //
+    // the Curve only specifies values for one component of the property,
+    // so there will be a separate AnimationCurve for X, Y, and Z.
+    //
+    // Assimp has:
+    // * aiAnimation - basically corresponds to an AnimationStack
+    // * aiNodeAnim - defines all animation for one aiNode
+    // * aiVectorKey/aiQuatKey - define the keyframe data for T/R/S
+    //
+    // assimp has no equivalent for AnimationLayer,
+    // and these are flattened on FBX import.
+    // we can assume there will be one per AnimationStack.
+    //
+    // the aiNodeAnim contains all animation data for a single aiNode,
+    // which will correspond to three AnimationCurveNode's:
+    // one each for translation, rotation and scale.
+    // The data for each of these will be put in 9 AnimationCurve's,
+    // T.X, T.Y, T.Z, R.X, R.Y, R.Z, etc.
+
+    // AnimationStack / aiAnimation
+    std::vector<int64_t> animation_stack_uids(mScene->mNumAnimations);
+    for (size_t ai = 0; ai < mScene->mNumAnimations; ++ai) {
+        int64_t animstack_uid = generate_uid();
+        animation_stack_uids[ai] = animstack_uid;
+        const aiAnimation* anim = mScene->mAnimations[ai];
+
+        FBX::Node asnode("AnimationStack");
+        std::string name = anim->mName.C_Str() + FBX::SEPARATOR + "AnimStack";
+        asnode.AddProperties(animstack_uid, name, "");
+        FBX::Node p("Properties70");
+        p.AddP70time("LocalStart", 0); // assimp doesn't store this
+        p.AddP70time("LocalStop", to_ktime(anim->mDuration, anim));
+        p.AddP70time("ReferenceStart", 0);
+        p.AddP70time("ReferenceStop", to_ktime(anim->mDuration, anim));
+        asnode.AddChild(p);
+
+        // this node absurdly always pretends it has children
+        // (in this case it does, but just in case...)
+        asnode.force_has_children = true;
+        asnode.Dump(outstream, binary, indent);
+
+        // note: animation stacks are not connected to anything
+    }
+
+    // AnimationLayer - one per aiAnimation
+    std::vector<int64_t> animation_layer_uids(mScene->mNumAnimations);
+    for (size_t ai = 0; ai < mScene->mNumAnimations; ++ai) {
+        int64_t animlayer_uid = generate_uid();
+        animation_layer_uids[ai] = animlayer_uid;
+        FBX::Node alnode("AnimationLayer");
+        alnode.AddProperties(animlayer_uid, FBX::SEPARATOR + "AnimLayer", "");
+
+        // this node absurdly always pretends it has children
+        alnode.force_has_children = true;
+        alnode.Dump(outstream, binary, indent);
+
+        // connect to the relevant animstack
+        connections.emplace_back(
+            "C", "OO", animlayer_uid, animation_stack_uids[ai]
+        );
+    }
+
+    // AnimCurveNode - three per aiNodeAnim
+    std::vector<std::vector<std::array<int64_t,3>>> curve_node_uids;
+    for (size_t ai = 0; ai < mScene->mNumAnimations; ++ai) {
+        const aiAnimation* anim = mScene->mAnimations[ai];
+        const int64_t layer_uid = animation_layer_uids[ai];
+        std::vector<std::array<int64_t,3>> nodeanim_uids;
+        for (size_t nai = 0; nai < anim->mNumChannels; ++nai) {
+            const aiNodeAnim* na = anim->mChannels[nai];
+            // get the corresponding aiNode
+            const aiNode* node = mScene->mRootNode->FindNode(na->mNodeName);
+            // and its transform
+            const aiMatrix4x4 node_xfm = get_world_transform(node, mScene);
+            aiVector3D T, R, S;
+            node_xfm.Decompose(S, R, T);
+
+            // AnimationCurveNode uids
+            std::array<int64_t,3> ids;
+            ids[0] = generate_uid(); // T
+            ids[1] = generate_uid(); // R
+            ids[2] = generate_uid(); // S
+
+            // translation
+            WriteAnimationCurveNode(outstream,
+                ids[0], "T", T, "Lcl Translation",
+                layer_uid, node_uids[node]
+            );
+
+            // rotation
+            WriteAnimationCurveNode(outstream,
+                ids[1], "R", R, "Lcl Rotation",
+                layer_uid, node_uids[node]
+            );
+
+            // scale
+            WriteAnimationCurveNode(outstream,
+                ids[2], "S", S, "Lcl Scale",
+                layer_uid, node_uids[node]
+            );
+
+            // store the uids for later use
+            nodeanim_uids.push_back(ids);
+        }
+        curve_node_uids.push_back(nodeanim_uids);
+    }
+
+    // AnimCurve - defines actual keyframe data.
+    // there's a separate curve for every component of every vector,
+    // for example a transform curvenode will have separate X/Y/Z AnimCurve's
+    for (size_t ai = 0; ai < mScene->mNumAnimations; ++ai) {
+        const aiAnimation* anim = mScene->mAnimations[ai];
+        for (size_t nai = 0; nai < anim->mNumChannels; ++nai) {
+            const aiNodeAnim* na = anim->mChannels[nai];
+            // get the corresponding aiNode
+            const aiNode* node = mScene->mRootNode->FindNode(na->mNodeName);
+            // and its transform
+            const aiMatrix4x4 node_xfm = get_world_transform(node, mScene);
+            aiVector3D T, R, S;
+            node_xfm.Decompose(S, R, T);
+            const std::array<int64_t,3>& ids = curve_node_uids[ai][nai];
+
+            std::vector<int64_t> times;
+            std::vector<float> xval, yval, zval;
+
+            // position/translation
+            for (size_t ki = 0; ki < na->mNumPositionKeys; ++ki) {
+                const aiVectorKey& k = na->mPositionKeys[ki];
+                times.push_back(to_ktime(k.mTime));
+                xval.push_back(k.mValue.x);
+                yval.push_back(k.mValue.y);
+                zval.push_back(k.mValue.z);
+            }
+            // one curve each for X, Y, Z
+            WriteAnimationCurve(outstream, T.x, times, xval, ids[0], "d|X");
+            WriteAnimationCurve(outstream, T.y, times, yval, ids[0], "d|Y");
+            WriteAnimationCurve(outstream, T.z, times, zval, ids[0], "d|Z");
+
+            // rotation
+            times.clear(); xval.clear(); yval.clear(); zval.clear();
+            for (size_t ki = 0; ki < na->mNumRotationKeys; ++ki) {
+                const aiQuatKey& k = na->mRotationKeys[ki];
+                times.push_back(to_ktime(k.mTime));
+                // TODO: aiQuaternion method to convert to Euler...
+                aiMatrix4x4 m(k.mValue.GetMatrix());
+                aiVector3D qs, qr, qt;
+                m.Decompose(qs, qr, qt);
+                qr *= DEG;
+                xval.push_back(qr.x);
+                yval.push_back(qr.y);
+                zval.push_back(qr.z);
+            }
+            WriteAnimationCurve(outstream, R.x, times, xval, ids[1], "d|X");
+            WriteAnimationCurve(outstream, R.y, times, yval, ids[1], "d|Y");
+            WriteAnimationCurve(outstream, R.z, times, zval, ids[1], "d|Z");
+
+            // scaling/scale
+            times.clear(); xval.clear(); yval.clear(); zval.clear();
+            for (size_t ki = 0; ki < na->mNumScalingKeys; ++ki) {
+                const aiVectorKey& k = na->mScalingKeys[ki];
+                times.push_back(to_ktime(k.mTime));
+                xval.push_back(k.mValue.x);
+                yval.push_back(k.mValue.y);
+                zval.push_back(k.mValue.z);
+            }
+            WriteAnimationCurve(outstream, S.x, times, xval, ids[2], "d|X");
+            WriteAnimationCurve(outstream, S.y, times, yval, ids[2], "d|Y");
+            WriteAnimationCurve(outstream, S.z, times, zval, ids[2], "d|Z");
+        }
+    }
+
+    indent = 0;
+    object_node.End(outstream, binary, indent, true);
+}
+
+// convenience map of magic node name strings to FBX properties,
+// including the expected type of transform.
+const std::map<std::string,std::pair<std::string,char>> transform_types = {
+    {"Translation", {"Lcl Translation", 't'}},
+    {"RotationOffset", {"RotationOffset", 't'}},
+    {"RotationPivot", {"RotationPivot", 't'}},
+    {"PreRotation", {"PreRotation", 'r'}},
+    {"Rotation", {"Lcl Rotation", 'r'}},
+    {"PostRotation", {"PostRotation", 'r'}},
+    {"RotationPivotInverse", {"RotationPivotInverse", 'i'}},
+    {"ScalingOffset", {"ScalingOffset", 't'}},
+    {"ScalingPivot", {"ScalingPivot", 't'}},
+    {"Scaling", {"Lcl Scaling", 's'}},
+    {"ScalingPivotInverse", {"ScalingPivotInverse", 'i'}},
+    {"GeometricScaling", {"GeometricScaling", 's'}},
+    {"GeometricRotation", {"GeometricRotation", 'r'}},
+    {"GeometricTranslation", {"GeometricTranslation", 't'}},
+    {"GeometricTranslationInverse", {"GeometricTranslationInverse", 'i'}},
+    {"GeometricRotationInverse", {"GeometricRotationInverse", 'i'}},
+    {"GeometricScalingInverse", {"GeometricScalingInverse", 'i'}}
+};
+
+// write a single model node to the stream
+void FBXExporter::WriteModelNode(
+    StreamWriterLE& outstream,
+    bool binary,
+    const aiNode* node,
+    int64_t node_uid,
+    const std::string& type,
+    const std::vector<std::pair<std::string,aiVector3D>>& transform_chain,
+    TransformInheritance inherit_type
+){
+    const aiVector3D zero = {0, 0, 0};
+    const aiVector3D one = {1, 1, 1};
+    FBX::Node m("Model");
+    std::string name = node->mName.C_Str() + FBX::SEPARATOR + "Model";
+    m.AddProperties(node_uid, name, type);
+    m.AddChild("Version", int32_t(232));
+    FBX::Node p("Properties70");
+    p.AddP70bool("RotationActive", 1);
+    p.AddP70int("DefaultAttributeIndex", 0);
+    p.AddP70enum("InheritType", inherit_type);
+    if (transform_chain.empty()) {
+        // decompose 4x4 transform matrix into TRS
+        aiVector3D t, r, s;
+        node->mTransformation.Decompose(s, r, t);
+        if (t != zero) {
+            p.AddP70(
+                "Lcl Translation", "Lcl Translation", "", "A",
+                double(t.x), double(t.y), double(t.z)
+            );
+        }
+        if (r != zero) {
+            p.AddP70(
+                "Lcl Rotation", "Lcl Rotation", "", "A",
+                double(DEG*r.x), double(DEG*r.y), double(DEG*r.z)
+            );
+        }
+        if (s != one) {
+            p.AddP70(
+                "Lcl Scaling", "Lcl Scaling", "", "A",
+                double(s.x), double(s.y), double(s.z)
+            );
+        }
+    } else {
+        // apply the transformation chain.
+        // these transformation elements are created when importing FBX,
+        // which has a complex transformation hierarchy for each node.
+        // as such we can bake the hierarchy back into the node on export.
+        for (auto &item : transform_chain) {
+            auto elem = transform_types.find(item.first);
+            if (elem == transform_types.end()) {
+                // then this is a bug
+                std::stringstream err;
+                err << "unrecognized FBX transformation type: ";
+                err << item.first;
+                throw DeadlyExportError(err.str());
+            }
+            const std::string &name = elem->second.first;
+            const aiVector3D &v = item.second;
+            if (name.compare(0, 4, "Lcl ") == 0) {
+                // special handling for animatable properties
+                p.AddP70(
+                    name, name, "", "A",
+                    double(v.x), double(v.y), double(v.z)
+                );
+            } else {
+                p.AddP70vector(name, v.x, v.y, v.z);
+            }
+        }
+    }
+    m.AddChild(p);
+
+    // not sure what these are for,
+    // but they seem to be omnipresent
+    m.AddChild("Shading", FBXExportProperty(true));
+    m.AddChild("Culling", FBXExportProperty("CullingOff"));
+
+    m.Dump(outstream, binary, 1);
+}
+
+// wrapper for WriteModelNodes to create and pass a blank transform chain
+void FBXExporter::WriteModelNodes(
+    StreamWriterLE& s,
+    const aiNode* node,
+    int64_t parent_uid,
+    const std::unordered_set<const aiNode*>& limbnodes
+) {
+    std::vector<std::pair<std::string,aiVector3D>> chain;
+    WriteModelNodes(s, node, parent_uid, limbnodes, chain);
+}
+
+void FBXExporter::WriteModelNodes(
+    StreamWriterLE& outstream,
+    const aiNode* node,
+    int64_t parent_uid,
+    const std::unordered_set<const aiNode*>& limbnodes,
+    std::vector<std::pair<std::string,aiVector3D>>& transform_chain
+) {
+    // first collapse any expanded transformation chains created by FBX import.
+    std::string node_name(node->mName.C_Str());
+    if (node_name.find(MAGIC_NODE_TAG) != std::string::npos) {
+        auto pos = node_name.find(MAGIC_NODE_TAG) + MAGIC_NODE_TAG.size() + 1;
+        std::string type_name = node_name.substr(pos);
+        auto elem = transform_types.find(type_name);
+        if (elem == transform_types.end()) {
+            // then this is a bug and should be fixed
+            std::stringstream err;
+            err << "unrecognized FBX transformation node";
+            err << " of type " << type_name << " in node " << node_name;
+            throw DeadlyExportError(err.str());
+        }
+        aiVector3D t, r, s;
+        node->mTransformation.Decompose(s, r, t);
+        switch (elem->second.second) {
+        case 'i': // inverse
+            // we don't need to worry about the inverse matrices
+            break;
+        case 't': // translation
+            transform_chain.emplace_back(elem->first, t);
+            break;
+        case 'r': // rotation
+            r *= float(DEG);
+            transform_chain.emplace_back(elem->first, r);
+            break;
+        case 's': // scale
+            transform_chain.emplace_back(elem->first, s);
+            break;
+        default:
+            // this should never happen
+            std::stringstream err;
+            err << "unrecognized FBX transformation type code: ";
+            err << elem->second.second;
+            throw DeadlyExportError(err.str());
+        }
+        // now continue on to any child nodes
+        for (unsigned i = 0; i < node->mNumChildren; ++i) {
+            WriteModelNodes(
+                outstream,
+                node->mChildren[i],
+                parent_uid,
+                limbnodes,
+                transform_chain
+            );
+        }
+        return;
+    }
+
+    int64_t node_uid = 0;
+    // generate uid and connect to parent, if not the root node,
+    if (node != mScene->mRootNode) {
+        auto elem = node_uids.find(node);
+        if (elem != node_uids.end()) {
+            node_uid = elem->second;
+        } else {
+            node_uid = generate_uid();
+            node_uids[node] = node_uid;
+        }
+        connections.emplace_back("C", "OO", node_uid, parent_uid);
+    }
+
+    // what type of node is this?
+    if (node == mScene->mRootNode) {
+        // handled later
+    } else if (node->mNumMeshes == 1) {
+        // connect to child mesh, which should have been written previously
+        connections.emplace_back(
+            "C", "OO", mesh_uids[node->mMeshes[0]], node_uid
+        );
+        // also connect to the material for the child mesh
+        connections.emplace_back(
+            "C", "OO",
+            material_uids[mScene->mMeshes[node->mMeshes[0]]->mMaterialIndex],
+            node_uid
+        );
+        // write model node
+        WriteModelNode(
+            outstream, binary, node, node_uid, "Mesh", transform_chain
+        );
+    } else if (limbnodes.count(node)) {
+        WriteModelNode(
+            outstream, binary, node, node_uid, "LimbNode", transform_chain
+        );
+        // we also need to write a nodeattribute to mark it as a skeleton
+        int64_t node_attribute_uid = generate_uid();
+        FBX::Node na("NodeAttribute");
+        na.AddProperties(
+            node_attribute_uid, FBX::SEPARATOR + "NodeAttribute", "LimbNode"
+        );
+        na.AddChild("TypeFlags", FBXExportProperty("Skeleton"));
+        na.Dump(outstream, binary, 1);
+        // and connect them
+        connections.emplace_back("C", "OO", node_attribute_uid, node_uid);
+    } else {
+        // generate a null node so we can add children to it
+        WriteModelNode(
+            outstream, binary, node, node_uid, "Null", transform_chain
+        );
+    }
+
+    // if more than one child mesh, make nodes for each mesh
+    if (node->mNumMeshes > 1 || node == mScene->mRootNode) {
+        for (size_t i = 0; i < node->mNumMeshes; ++i) {
+            // make a new model node
+            int64_t new_node_uid = generate_uid();
+            // connect to parent node
+            connections.emplace_back("C", "OO", new_node_uid, node_uid);
+            // connect to child mesh, which should have been written previously
+            connections.emplace_back(
+                "C", "OO", mesh_uids[node->mMeshes[i]], new_node_uid
+            );
+            // also connect to the material for the child mesh
+            connections.emplace_back(
+                "C", "OO",
+                material_uids[
+                    mScene->mMeshes[node->mMeshes[i]]->mMaterialIndex
+                ],
+                new_node_uid
+            );
+            // write model node
+            FBX::Node m("Model");
+            // take name from mesh name, if it exists
+            std::string name = mScene->mMeshes[node->mMeshes[i]]->mName.C_Str();
+            name += FBX::SEPARATOR + "Model";
+            m.AddProperties(new_node_uid, name, "Mesh");
+            m.AddChild("Version", int32_t(232));
+            FBX::Node p("Properties70");
+            p.AddP70enum("InheritType", 1);
+            m.AddChild(p);
+            m.Dump(outstream, binary, 1);
+        }
+    }
+
+    // now recurse into children
+    for (size_t i = 0; i < node->mNumChildren; ++i) {
+        WriteModelNodes(
+            outstream, node->mChildren[i], node_uid, limbnodes
+        );
+    }
+}
+
+
+void FBXExporter::WriteAnimationCurveNode(
+    StreamWriterLE& outstream,
+    int64_t uid,
+    std::string name, // "T", "R", or "S"
+    aiVector3D default_value,
+    std::string property_name, // "Lcl Translation" etc
+    int64_t layer_uid,
+    int64_t node_uid
+) {
+    FBX::Node n("AnimationCurveNode");
+    n.AddProperties(uid, name + FBX::SEPARATOR + "AnimCurveNode", "");
+    FBX::Node p("Properties70");
+    p.AddP70numberA("d|X", default_value.x);
+    p.AddP70numberA("d|Y", default_value.y);
+    p.AddP70numberA("d|Z", default_value.z);
+    n.AddChild(p);
+    n.Dump(outstream, binary, 1);
+    // connect to layer
+    this->connections.emplace_back("C", "OO", uid, layer_uid);
+    // connect to bone
+    this->connections.emplace_back("C", "OP", uid, node_uid, property_name);
+}
+
+
+void FBXExporter::WriteAnimationCurve(
+    StreamWriterLE& outstream,
+    double default_value,
+    const std::vector<int64_t>& times,
+    const std::vector<float>& values,
+    int64_t curvenode_uid,
+    const std::string& property_link // "d|X", "d|Y", etc
+) {
+    FBX::Node n("AnimationCurve");
+    int64_t curve_uid = generate_uid();
+    n.AddProperties(curve_uid, FBX::SEPARATOR + "AnimCurve", "");
+    n.AddChild("Default", default_value);
+    n.AddChild("KeyVer", int32_t(4009));
+    n.AddChild("KeyTime", times);
+    n.AddChild("KeyValueFloat", values);
+    // TODO: keyattr flags and data (STUB for now)
+    n.AddChild("KeyAttrFlags", std::vector<int32_t>{0});
+    n.AddChild("KeyAttrDataFloat", std::vector<float>{0,0,0,0});
+    n.AddChild(
+        "KeyAttrRefCount",
+        std::vector<int32_t>{static_cast<int32_t>(times.size())}
+    );
+    n.Dump(outstream, binary, 1);
+    this->connections.emplace_back(
+        "C", "OP", curve_uid, curvenode_uid, property_link
+    );
+}
+
+
+void FBXExporter::WriteConnections ()
+{
+    // we should have completed the connection graph already,
+    // so basically just dump it here
+    if (!binary) {
+        WriteAsciiSectionHeader("Object connections");
+    }
+    // TODO: comments with names in the ascii version
+    FBX::Node conn("Connections");
+    StreamWriterLE outstream(outfile);
+    conn.Begin(outstream, binary, 0);
+    conn.BeginChildren(outstream, binary, 0);
+    for (auto &n : connections) {
+        n.Dump(outstream, binary, 1);
+    }
+    conn.End(outstream, binary, 0, !connections.empty());
+    connections.clear();
+}
+
+#endif // ASSIMP_BUILD_NO_FBX_EXPORTER
+#endif // ASSIMP_BUILD_NO_EXPORT
diff --git a/thirdparty/assimp/code/FBX/FBXExporter.h b/thirdparty/assimp/code/FBX/FBXExporter.h
new file mode 100644
index 0000000000..71fb55c57f
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXExporter.h
@@ -0,0 +1,178 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+copyright notice, this list of conditions and the
+following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other
+materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+contributors may be used to endorse or promote products
+derived from this software without specific prior
+written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file FBXExporter.h
+* Declares the exporter class to write a scene to an fbx file
+*/
+#ifndef AI_FBXEXPORTER_H_INC
+#define AI_FBXEXPORTER_H_INC
+
+#ifndef ASSIMP_BUILD_NO_FBX_EXPORTER
+
+#include "FBXExportNode.h" // FBX::Node
+#include "FBXCommon.h" // FBX::TransformInheritance
+
+#include <assimp/types.h>
+//#include <assimp/material.h>
+#include <assimp/StreamWriter.h> // StreamWriterLE
+#include <assimp/Exceptional.h> // DeadlyExportError
+
+#include <vector>
+#include <map>
+#include <unordered_set>
+#include <memory> // shared_ptr
+#include <sstream> // stringstream
+
+struct aiScene;
+struct aiNode;
+//struct aiMaterial;
+
+namespace Assimp
+{
+    class IOSystem;
+    class IOStream;
+    class ExportProperties;
+
+    // ---------------------------------------------------------------------
+    /** Helper class to export a given scene to an FBX file. */
+    // ---------------------------------------------------------------------
+    class FBXExporter
+    {
+    public:
+        /// Constructor for a specific scene to export
+        FBXExporter(const aiScene* pScene, const ExportProperties* pProperties);
+
+        // call one of these methods to export
+        void ExportBinary(const char* pFile, IOSystem* pIOSystem);
+        void ExportAscii(const char* pFile, IOSystem* pIOSystem);
+
+    private:
+        bool binary; // whether current export is in binary or ascii format
+        const aiScene* mScene; // the scene to export
+        const ExportProperties* mProperties; // currently unused
+        std::shared_ptr<IOStream> outfile; // file to write to
+
+        std::vector<FBX::Node> connections; // connection storage
+
+        std::vector<int64_t> mesh_uids;
+        std::vector<int64_t> material_uids;
+        std::map<const aiNode*,int64_t> node_uids;
+
+        // this crude unique-ID system is actually fine
+        int64_t last_uid = 999999;
+        int64_t generate_uid() { return ++last_uid; }
+
+        // binary files have a specific header and footer,
+        // in addition to the actual data
+        void WriteBinaryHeader();
+        void WriteBinaryFooter();
+
+        // ascii files have a comment at the top
+        void WriteAsciiHeader();
+
+        // WriteAllNodes does the actual export.
+        // It just calls all the Write<Section> methods below in order.
+        void WriteAllNodes();
+
+        // Methods to write individual sections.
+        // The order here matches the order inside an FBX file.
+        // Each method corresponds to a top-level FBX section,
+        // except WriteHeader which also includes some binary-only sections
+        // and WriteFooter which is binary data only.
+        void WriteHeaderExtension();
+        // WriteFileId(); // binary-only, included in WriteHeader
+        // WriteCreationTime(); // binary-only, included in WriteHeader
+        // WriteCreator(); // binary-only, included in WriteHeader
+        void WriteGlobalSettings();
+        void WriteDocuments();
+        void WriteReferences();
+        void WriteDefinitions();
+        void WriteObjects();
+        void WriteConnections();
+        // WriteTakes(); // deprecated since at least 2015 (fbx 7.4)
+
+        // helpers
+        void WriteAsciiSectionHeader(const std::string& title);
+        void WriteModelNodes(
+            Assimp::StreamWriterLE& s,
+            const aiNode* node,
+            int64_t parent_uid,
+            const std::unordered_set<const aiNode*>& limbnodes
+        );
+        void WriteModelNodes( // usually don't call this directly
+            StreamWriterLE& s,
+            const aiNode* node,
+            int64_t parent_uid,
+            const std::unordered_set<const aiNode*>& limbnodes,
+            std::vector<std::pair<std::string,aiVector3D>>& transform_chain
+        );
+        void WriteModelNode( // nor this
+            StreamWriterLE& s,
+            bool binary,
+            const aiNode* node,
+            int64_t node_uid,
+            const std::string& type,
+            const std::vector<std::pair<std::string,aiVector3D>>& xfm_chain,
+            FBX::TransformInheritance ti_type=FBX::TransformInheritance_RSrs
+        );
+        void WriteAnimationCurveNode(
+            StreamWriterLE& outstream,
+            int64_t uid,
+            std::string name, // "T", "R", or "S"
+            aiVector3D default_value,
+            std::string property_name, // "Lcl Translation" etc
+            int64_t animation_layer_uid,
+            int64_t node_uid
+        );
+        void WriteAnimationCurve(
+            StreamWriterLE& outstream,
+            double default_value,
+            const std::vector<int64_t>& times,
+            const std::vector<float>& values,
+            int64_t curvenode_id,
+            const std::string& property_link // "d|X", "d|Y", etc
+        );
+    };
+}
+
+#endif // ASSIMP_BUILD_NO_FBX_EXPORTER
+
+#endif // AI_FBXEXPORTER_H_INC
diff --git a/thirdparty/assimp/code/FBX/FBXImportSettings.h b/thirdparty/assimp/code/FBX/FBXImportSettings.h
new file mode 100644
index 0000000000..1a4c80f8b2
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXImportSettings.h
@@ -0,0 +1,164 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXImportSettings.h
+ *  @brief FBX importer runtime configuration
+ */
+#ifndef INCLUDED_AI_FBX_IMPORTSETTINGS_H
+#define INCLUDED_AI_FBX_IMPORTSETTINGS_H
+
+namespace Assimp {
+namespace FBX {
+
+/** FBX import settings, parts of which are publicly accessible via their corresponding AI_CONFIG constants */
+struct ImportSettings
+{
+    ImportSettings()
+    : strictMode(true)
+    , readAllLayers(true)
+    , readAllMaterials(false)
+    , readMaterials(true)
+    , readTextures(true)
+    , readCameras(true)
+    , readLights(true)
+    , readAnimations(true)
+    , readWeights(true)
+    , preservePivots(true)
+    , optimizeEmptyAnimationCurves(true)
+    , useLegacyEmbeddedTextureNaming(false)
+    , removeEmptyBones( true )
+    , convertToMeters( false ) {
+        // empty
+    }
+
+
+    /** enable strict mode:
+     *   - only accept fbx 2012, 2013 files
+     *   - on the slightest error, give up.
+     *
+     *  Basically, strict mode means that the fbx file will actually
+     *  be validated. Strict mode is off by default. */
+    bool strictMode;
+
+    /** specifies whether all geometry layers are read and scanned for
+      * usable data channels. The FBX spec indicates that many readers
+      * will only read the first channel and that this is in some way
+      * the recommended way- in reality, however, it happens a lot that
+      * vertex data is spread among multiple layers. The default
+      * value for this option is true.*/
+    bool readAllLayers;
+
+    /** specifies whether all materials are read, or only those that
+     *  are referenced by at least one mesh. Reading all materials
+     *  may make FBX reading a lot slower since all objects
+     *  need to be processed .
+     *  This bit is ignored unless readMaterials=true*/
+    bool readAllMaterials;
+
+
+    /** import materials (true) or skip them and assign a default
+     *  material. The default value is true.*/
+    bool readMaterials;
+
+    /** import embedded textures? Default value is true.*/
+    bool readTextures;
+
+    /** import cameras? Default value is true.*/
+    bool readCameras;
+
+    /** import light sources? Default value is true.*/
+    bool readLights;
+
+    /** import animations (i.e. animation curves, the node
+     *  skeleton is always imported). Default value is true. */
+    bool readAnimations;
+
+    /** read bones (vertex weights and deform info).
+     *  Default value is true. */
+    bool readWeights;
+
+    /** preserve transformation pivots and offsets. Since these can
+     *  not directly be represented in assimp, additional dummy
+     *  nodes will be generated. Note that settings this to false
+     *  can make animation import a lot slower. The default value
+     *  is true.
+     *
+     *  The naming scheme for the generated nodes is:
+     *    <OriginalName>_$AssimpFbx$_<TransformName>
+     *
+     *  where <TransformName> is one of
+     *    RotationPivot
+     *    RotationOffset
+     *    PreRotation
+     *    PostRotation
+     *    ScalingPivot
+     *    ScalingOffset
+     *    Translation
+     *    Scaling
+     *    Rotation
+     **/
+    bool preservePivots;
+
+    /** do not import animation curves that specify a constant
+     *  values matching the corresponding node transformation.
+     *  The default value is true. */
+    bool optimizeEmptyAnimationCurves;
+
+    /** use legacy naming for embedded textures eg: (*0, *1, *2)
+    */
+    bool useLegacyEmbeddedTextureNaming;
+
+    /** Empty bones shall be removed
+    */
+    bool removeEmptyBones;
+
+    /** Set to true to perform a conversion from cm to meter after the import
+    */
+    bool convertToMeters;
+};
+
+
+} // !FBX
+} // !Assimp
+
+#endif
+
diff --git a/thirdparty/assimp/code/FBX/FBXImporter.cpp b/thirdparty/assimp/code/FBX/FBXImporter.cpp
new file mode 100644
index 0000000000..ec8bbd2b47
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXImporter.cpp
@@ -0,0 +1,203 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+r
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXImporter.cpp
+ *  @brief Implementation of the FBX importer.
+ */
+
+#ifndef ASSIMP_BUILD_NO_FBX_IMPORTER
+
+#include "FBXImporter.h"
+
+#include "FBXTokenizer.h"
+#include "FBXParser.h"
+#include "FBXUtil.h"
+#include "FBXDocument.h"
+#include "FBXConverter.h"
+
+#include <assimp/StreamReader.h>
+#include <assimp/MemoryIOWrapper.h>
+#include <assimp/Importer.hpp>
+#include <assimp/importerdesc.h>
+
+namespace Assimp {
+
+template<>
+const char* LogFunctions<FBXImporter>::Prefix() {
+    static auto prefix = "FBX: ";
+    return prefix;
+}
+
+}
+
+using namespace Assimp;
+using namespace Assimp::Formatter;
+using namespace Assimp::FBX;
+
+namespace {
+
+static const aiImporterDesc desc = {
+    "Autodesk FBX Importer",
+    "",
+    "",
+    "",
+    aiImporterFlags_SupportTextFlavour,
+    0,
+    0,
+    0,
+    0,
+    "fbx"
+};
+}
+
+// ------------------------------------------------------------------------------------------------
+// Constructor to be privately used by #Importer
+FBXImporter::FBXImporter()
+{
+}
+
+// ------------------------------------------------------------------------------------------------
+// Destructor, private as well
+FBXImporter::~FBXImporter()
+{
+}
+
+// ------------------------------------------------------------------------------------------------
+// Returns whether the class can handle the format of the given file.
+bool FBXImporter::CanRead( const std::string& pFile, IOSystem* pIOHandler, bool checkSig) const
+{
+    const std::string& extension = GetExtension(pFile);
+    if (extension == std::string( desc.mFileExtensions ) ) {
+        return true;
+    }
+
+    else if ((!extension.length() || checkSig) && pIOHandler)   {
+        // at least ASCII-FBX files usually have a 'FBX' somewhere in their head
+        const char* tokens[] = {"fbx"};
+        return SearchFileHeaderForToken(pIOHandler,pFile,tokens,1);
+    }
+    return false;
+}
+
+// ------------------------------------------------------------------------------------------------
+// List all extensions handled by this loader
+const aiImporterDesc* FBXImporter::GetInfo () const
+{
+    return &desc;
+}
+
+// ------------------------------------------------------------------------------------------------
+// Setup configuration properties for the loader
+void FBXImporter::SetupProperties(const Importer* pImp)
+{
+    settings.readAllLayers = pImp->GetPropertyBool(AI_CONFIG_IMPORT_FBX_READ_ALL_GEOMETRY_LAYERS, true);
+    settings.readAllMaterials = pImp->GetPropertyBool(AI_CONFIG_IMPORT_FBX_READ_ALL_MATERIALS, false);
+    settings.readMaterials = pImp->GetPropertyBool(AI_CONFIG_IMPORT_FBX_READ_MATERIALS, true);
+    settings.readTextures = pImp->GetPropertyBool(AI_CONFIG_IMPORT_FBX_READ_TEXTURES, true);
+    settings.readCameras = pImp->GetPropertyBool(AI_CONFIG_IMPORT_FBX_READ_CAMERAS, true);
+    settings.readLights = pImp->GetPropertyBool(AI_CONFIG_IMPORT_FBX_READ_LIGHTS, true);
+    settings.readAnimations = pImp->GetPropertyBool(AI_CONFIG_IMPORT_FBX_READ_ANIMATIONS, true);
+    settings.strictMode = pImp->GetPropertyBool(AI_CONFIG_IMPORT_FBX_STRICT_MODE, false);
+    settings.preservePivots = pImp->GetPropertyBool(AI_CONFIG_IMPORT_FBX_PRESERVE_PIVOTS, true);
+    settings.optimizeEmptyAnimationCurves = pImp->GetPropertyBool(AI_CONFIG_IMPORT_FBX_OPTIMIZE_EMPTY_ANIMATION_CURVES, true);
+    settings.useLegacyEmbeddedTextureNaming = pImp->GetPropertyBool(AI_CONFIG_IMPORT_FBX_EMBEDDED_TEXTURES_LEGACY_NAMING, false);
+    settings.removeEmptyBones = pImp->GetPropertyBool(AI_CONFIG_IMPORT_REMOVE_EMPTY_BONES, true);
+    settings.convertToMeters = pImp->GetPropertyBool(AI_CONFIG_FBX_CONVERT_TO_M, false);
+}
+
+// ------------------------------------------------------------------------------------------------
+// Imports the given file into the given scene structure.
+void FBXImporter::InternReadFile( const std::string& pFile, aiScene* pScene, IOSystem* pIOHandler)
+{
+    std::unique_ptr<IOStream> stream(pIOHandler->Open(pFile,"rb"));
+    if (!stream) {
+        ThrowException("Could not open file for reading");
+    }
+
+    // read entire file into memory - no streaming for this, fbx
+    // files can grow large, but the assimp output data structure
+    // then becomes very large, too. Assimp doesn't support
+    // streaming for its output data structures so the net win with
+    // streaming input data would be very low.
+    std::vector<char> contents;
+    contents.resize(stream->FileSize()+1);
+    stream->Read( &*contents.begin(), 1, contents.size()-1 );
+    contents[ contents.size() - 1 ] = 0;
+    const char* const begin = &*contents.begin();
+
+    // broadphase tokenizing pass in which we identify the core
+    // syntax elements of FBX (brackets, commas, key:value mappings)
+    TokenList tokens;
+    try {
+
+        bool is_binary = false;
+        if (!strncmp(begin,"Kaydara FBX Binary",18)) {
+            is_binary = true;
+            TokenizeBinary(tokens,begin,contents.size());
+        }
+        else {
+            Tokenize(tokens,begin);
+        }
+
+        // use this information to construct a very rudimentary
+        // parse-tree representing the FBX scope structure
+        Parser parser(tokens, is_binary);
+
+        // take the raw parse-tree and convert it to a FBX DOM
+        Document doc(parser,settings);
+
+        FbxUnit unit(FbxUnit::cm);
+        if (settings.convertToMeters) {
+            unit = FbxUnit::m;
+        }
+        // convert the FBX DOM to aiScene
+        ConvertToAssimpScene(pScene,doc, settings.removeEmptyBones, unit);
+
+        std::for_each(tokens.begin(),tokens.end(),Util::delete_fun<Token>());
+    }
+    catch(std::exception&) {
+        std::for_each(tokens.begin(),tokens.end(),Util::delete_fun<Token>());
+        throw;
+    }
+}
+
+#endif // !ASSIMP_BUILD_NO_FBX_IMPORTER
diff --git a/thirdparty/assimp/code/FBX/FBXImporter.h b/thirdparty/assimp/code/FBX/FBXImporter.h
new file mode 100644
index 0000000000..c365b2cddf
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXImporter.h
@@ -0,0 +1,100 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXImporter.h
+ *  @brief Declaration of the FBX main importer class
+ */
+#ifndef INCLUDED_AI_FBX_IMPORTER_H
+#define INCLUDED_AI_FBX_IMPORTER_H
+
+#include <assimp/BaseImporter.h>
+#include <assimp/LogAux.h>
+
+#include "FBXImportSettings.h"
+
+namespace Assimp    {
+
+// TinyFormatter.h
+namespace Formatter {
+    template <typename T,typename TR, typename A> class basic_formatter;
+    typedef class basic_formatter< char, std::char_traits<char>, std::allocator<char> > format;
+}
+
+// -------------------------------------------------------------------------------------------
+/** Load the Autodesk FBX file format.
+
+ See http://en.wikipedia.org/wiki/FBX
+*/
+// -------------------------------------------------------------------------------------------
+class FBXImporter : public BaseImporter, public LogFunctions<FBXImporter>
+{
+public:
+    FBXImporter();
+    virtual ~FBXImporter();
+
+    // --------------------
+    bool CanRead( const std::string& pFile,
+        IOSystem* pIOHandler,
+        bool checkSig
+    ) const;
+
+protected:
+
+    // --------------------
+    const aiImporterDesc* GetInfo () const;
+
+    // --------------------
+    void SetupProperties(const Importer* pImp);
+
+    // --------------------
+    void InternReadFile( const std::string& pFile,
+        aiScene* pScene,
+        IOSystem* pIOHandler
+    );
+
+private:
+    FBX::ImportSettings settings;
+}; // !class FBXImporter
+
+} // end of namespace Assimp
+#endif // !INCLUDED_AI_FBX_IMPORTER_H
+
diff --git a/thirdparty/assimp/code/FBX/FBXMaterial.cpp b/thirdparty/assimp/code/FBX/FBXMaterial.cpp
new file mode 100644
index 0000000000..f43a8b84b0
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXMaterial.cpp
@@ -0,0 +1,405 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXMaterial.cpp
+ *  @brief Assimp::FBX::Material and Assimp::FBX::Texture implementation
+ */
+
+#ifndef ASSIMP_BUILD_NO_FBX_IMPORTER
+
+#include "FBXParser.h"
+#include "FBXDocument.h"
+#include "FBXImporter.h"
+#include "FBXImportSettings.h"
+#include "FBXDocumentUtil.h"
+#include "FBXProperties.h"
+#include <assimp/ByteSwapper.h>
+
+#include <algorithm> // std::transform
+#include "FBXUtil.h"
+
+namespace Assimp {
+namespace FBX {
+
+    using namespace Util;
+
+// ------------------------------------------------------------------------------------------------
+Material::Material(uint64_t id, const Element& element, const Document& doc, const std::string& name)
+: Object(id,element,name)
+{
+    const Scope& sc = GetRequiredScope(element);
+
+    const Element* const ShadingModel = sc["ShadingModel"];
+    const Element* const MultiLayer = sc["MultiLayer"];
+
+    if(MultiLayer) {
+        multilayer = !!ParseTokenAsInt(GetRequiredToken(*MultiLayer,0));
+    }
+
+    if(ShadingModel) {
+        shading = ParseTokenAsString(GetRequiredToken(*ShadingModel,0));
+    }
+    else {
+        DOMWarning("shading mode not specified, assuming phong",&element);
+        shading = "phong";
+    }
+
+    std::string templateName;
+
+    // lower-case shading because Blender (for example) writes "Phong"
+    std::transform(shading.begin(), shading.end(), shading.begin(), ::tolower);
+    if(shading == "phong") {
+        templateName = "Material.FbxSurfacePhong";
+    }
+    else if(shading == "lambert") {
+        templateName = "Material.FbxSurfaceLambert";
+    }
+    else {
+        DOMWarning("shading mode not recognized: " + shading,&element);
+    }
+
+    props = GetPropertyTable(doc,templateName,element,sc);
+
+    // resolve texture links
+    const std::vector<const Connection*>& conns = doc.GetConnectionsByDestinationSequenced(ID());
+    for(const Connection* con : conns) {
+
+        // texture link to properties, not objects
+        if (!con->PropertyName().length()) {
+            continue;
+        }
+
+        const Object* const ob = con->SourceObject();
+        if(!ob) {
+            DOMWarning("failed to read source object for texture link, ignoring",&element);
+            continue;
+        }
+
+        const Texture* const tex = dynamic_cast<const Texture*>(ob);
+        if(!tex) {
+            const LayeredTexture* const layeredTexture = dynamic_cast<const LayeredTexture*>(ob);
+            if(!layeredTexture) {
+                DOMWarning("source object for texture link is not a texture or layered texture, ignoring",&element);
+                continue;
+            }
+            const std::string& prop = con->PropertyName();
+            if (layeredTextures.find(prop) != layeredTextures.end()) {
+                DOMWarning("duplicate layered texture link: " + prop,&element);
+            }
+
+            layeredTextures[prop] = layeredTexture;
+            ((LayeredTexture*)layeredTexture)->fillTexture(doc);
+        }
+        else
+        {
+            const std::string& prop = con->PropertyName();
+            if (textures.find(prop) != textures.end()) {
+                DOMWarning("duplicate texture link: " + prop,&element);
+            }
+
+            textures[prop] = tex;
+        }
+
+    }
+}
+
+
+// ------------------------------------------------------------------------------------------------
+Material::~Material()
+{
+}
+
+
+// ------------------------------------------------------------------------------------------------
+Texture::Texture(uint64_t id, const Element& element, const Document& doc, const std::string& name)
+: Object(id,element,name)
+, uvScaling(1.0f,1.0f)
+, media(0)
+{
+    const Scope& sc = GetRequiredScope(element);
+
+    const Element* const Type = sc["Type"];
+    const Element* const FileName = sc["FileName"];
+    const Element* const RelativeFilename = sc["RelativeFilename"];
+    const Element* const ModelUVTranslation = sc["ModelUVTranslation"];
+    const Element* const ModelUVScaling = sc["ModelUVScaling"];
+    const Element* const Texture_Alpha_Source = sc["Texture_Alpha_Source"];
+    const Element* const Cropping = sc["Cropping"];
+
+    if(Type) {
+        type = ParseTokenAsString(GetRequiredToken(*Type,0));
+    }
+
+    if(FileName) {
+        fileName = ParseTokenAsString(GetRequiredToken(*FileName,0));
+    }
+
+    if(RelativeFilename) {
+        relativeFileName = ParseTokenAsString(GetRequiredToken(*RelativeFilename,0));
+    }
+
+    if(ModelUVTranslation) {
+        uvTrans = aiVector2D(ParseTokenAsFloat(GetRequiredToken(*ModelUVTranslation,0)),
+            ParseTokenAsFloat(GetRequiredToken(*ModelUVTranslation,1))
+        );
+    }
+
+    if(ModelUVScaling) {
+        uvScaling = aiVector2D(ParseTokenAsFloat(GetRequiredToken(*ModelUVScaling,0)),
+            ParseTokenAsFloat(GetRequiredToken(*ModelUVScaling,1))
+        );
+    }
+
+    if(Cropping) {
+        crop[0] = ParseTokenAsInt(GetRequiredToken(*Cropping,0));
+        crop[1] = ParseTokenAsInt(GetRequiredToken(*Cropping,1));
+        crop[2] = ParseTokenAsInt(GetRequiredToken(*Cropping,2));
+        crop[3] = ParseTokenAsInt(GetRequiredToken(*Cropping,3));
+    }
+    else {
+        // vc8 doesn't support the crop() syntax in initialization lists
+        // (and vc9 WARNS about the new (i.e. compliant) behaviour).
+        crop[0] = crop[1] = crop[2] = crop[3] = 0;
+    }
+
+    if(Texture_Alpha_Source) {
+        alphaSource = ParseTokenAsString(GetRequiredToken(*Texture_Alpha_Source,0));
+    }
+
+    props = GetPropertyTable(doc,"Texture.FbxFileTexture",element,sc);
+
+    // 3DS Max and FBX SDK use "Scaling" and "Translation" instead of "ModelUVScaling" and "ModelUVTranslation". Use these properties if available.
+    bool ok;
+    const aiVector3D& scaling = PropertyGet<aiVector3D>(*props, "Scaling", ok);
+    if (ok) {
+        uvScaling.x = scaling.x;
+        uvScaling.y = scaling.y;
+    }
+
+    const aiVector3D& trans = PropertyGet<aiVector3D>(*props, "Translation", ok);
+    if (ok) {
+        uvTrans.x = trans.x;
+        uvTrans.y = trans.y;
+    }
+
+    // resolve video links
+    if(doc.Settings().readTextures) {
+        const std::vector<const Connection*>& conns = doc.GetConnectionsByDestinationSequenced(ID());
+        for(const Connection* con : conns) {
+            const Object* const ob = con->SourceObject();
+            if(!ob) {
+                DOMWarning("failed to read source object for texture link, ignoring",&element);
+                continue;
+            }
+
+            const Video* const video = dynamic_cast<const Video*>(ob);
+            if(video) {
+                media = video;
+            }
+        }
+    }
+}
+
+
+Texture::~Texture()
+{
+
+}
+
+LayeredTexture::LayeredTexture(uint64_t id, const Element& element, const Document& /*doc*/, const std::string& name)
+: Object(id,element,name)
+,blendMode(BlendMode_Modulate)
+,alpha(1)
+{
+    const Scope& sc = GetRequiredScope(element);
+
+    const Element* const BlendModes = sc["BlendModes"];
+    const Element* const Alphas = sc["Alphas"];
+
+
+    if(BlendModes!=0)
+    {
+        blendMode = (BlendMode)ParseTokenAsInt(GetRequiredToken(*BlendModes,0));
+    }
+    if(Alphas!=0)
+    {
+        alpha = ParseTokenAsFloat(GetRequiredToken(*Alphas,0));
+    }
+}
+
+LayeredTexture::~LayeredTexture()
+{
+    
+}
+
+void LayeredTexture::fillTexture(const Document& doc)
+{
+    const std::vector<const Connection*>& conns = doc.GetConnectionsByDestinationSequenced(ID());
+    for(size_t i = 0; i < conns.size();++i)
+    {
+        const Connection* con = conns.at(i);
+
+        const Object* const ob = con->SourceObject();
+        if(!ob) {
+            DOMWarning("failed to read source object for texture link, ignoring",&element);
+            continue;
+        }
+
+        const Texture* const tex = dynamic_cast<const Texture*>(ob);
+
+        textures.push_back(tex);
+    }
+}
+
+
+// ------------------------------------------------------------------------------------------------
+Video::Video(uint64_t id, const Element& element, const Document& doc, const std::string& name)
+: Object(id,element,name)
+, contentLength(0)
+, content(0)
+{
+    const Scope& sc = GetRequiredScope(element);
+
+    const Element* const Type = sc["Type"];
+    const Element* const FileName = sc.FindElementCaseInsensitive("FileName");  //some files retain the information as "Filename", others "FileName", who knows
+    const Element* const RelativeFilename = sc["RelativeFilename"];
+    const Element* const Content = sc["Content"];
+
+    if(Type) {
+        type = ParseTokenAsString(GetRequiredToken(*Type,0));
+    }
+
+    if(FileName) {
+        fileName = ParseTokenAsString(GetRequiredToken(*FileName,0));
+    }
+
+    if(RelativeFilename) {
+        relativeFileName = ParseTokenAsString(GetRequiredToken(*RelativeFilename,0));
+    }
+
+    if(Content && !Content->Tokens().empty()) {
+        //this field is omitted when the embedded texture is already loaded, let's ignore if it's not found
+        try {
+            const Token& token = GetRequiredToken(*Content, 0);
+            const char* data = token.begin();
+            if (!token.IsBinary()) {
+                if (*data != '"') {
+                    DOMError("embedded content is not surrounded by quotation marks", &element);
+                }
+                else {
+                    size_t targetLength = 0;
+                    auto numTokens = Content->Tokens().size();
+                    // First time compute size (it could be large like 64Gb and it is good to allocate it once)
+                    for (uint32_t tokenIdx = 0; tokenIdx < numTokens; ++tokenIdx)
+                    {
+                        const Token& dataToken = GetRequiredToken(*Content, tokenIdx);
+                        size_t tokenLength = dataToken.end() - dataToken.begin() - 2; // ignore double quotes
+                        const char* base64data = dataToken.begin() + 1;
+                        const size_t outLength = Util::ComputeDecodedSizeBase64(base64data, tokenLength);
+                        if (outLength == 0)
+                        {
+                            DOMError("Corrupted embedded content found", &element);
+                        }
+                        targetLength += outLength;
+                    }
+                    if (targetLength == 0)
+                    {
+                        DOMError("Corrupted embedded content found", &element);
+                    }
+                    content = new uint8_t[targetLength];
+                    contentLength = static_cast<uint64_t>(targetLength);
+                    size_t dst_offset = 0;
+                    for (uint32_t tokenIdx = 0; tokenIdx < numTokens; ++tokenIdx)
+                    {
+                        const Token& dataToken = GetRequiredToken(*Content, tokenIdx);
+                        size_t tokenLength = dataToken.end() - dataToken.begin() - 2; // ignore double quotes
+                        const char* base64data = dataToken.begin() + 1;
+                        dst_offset += Util::DecodeBase64(base64data, tokenLength, content + dst_offset, targetLength - dst_offset);
+                    }
+                    if (targetLength != dst_offset)
+                    {
+                        delete[] content;
+                        contentLength = 0;
+                        DOMError("Corrupted embedded content found", &element);
+                    }
+                }
+            }
+            else if (static_cast<size_t>(token.end() - data) < 5) {
+                DOMError("binary data array is too short, need five (5) bytes for type signature and element count", &element);
+            }
+            else if (*data != 'R') {
+                DOMWarning("video content is not raw binary data, ignoring", &element);
+            }
+            else {
+                // read number of elements
+                uint32_t len = 0;
+                ::memcpy(&len, data + 1, sizeof(len));
+                AI_SWAP4(len);
+
+                contentLength = len;
+
+                content = new uint8_t[len];
+                ::memcpy(content, data + 5, len);
+            }
+        } catch (const runtime_error& runtimeError)
+        {
+            //we don't need the content data for contents that has already been loaded
+            ASSIMP_LOG_DEBUG_F("Caught exception in FBXMaterial (likely because content was already loaded): ",
+                    runtimeError.what());
+        }
+    }
+
+    props = GetPropertyTable(doc,"Video.FbxVideo",element,sc);
+}
+
+
+Video::~Video()
+{
+    if(content) {
+        delete[] content;
+    }
+}
+
+} //!FBX
+} //!Assimp
+
+#endif
diff --git a/thirdparty/assimp/code/FBX/FBXMeshGeometry.cpp b/thirdparty/assimp/code/FBX/FBXMeshGeometry.cpp
new file mode 100644
index 0000000000..44a0264ca0
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXMeshGeometry.cpp
@@ -0,0 +1,712 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXMeshGeometry.cpp
+ *  @brief Assimp::FBX::MeshGeometry implementation
+ */
+
+#ifndef ASSIMP_BUILD_NO_FBX_IMPORTER
+
+#include <functional>
+
+#include "FBXMeshGeometry.h"
+#include "FBXDocument.h"
+#include "FBXImporter.h"
+#include "FBXImportSettings.h"
+#include "FBXDocumentUtil.h"
+
+
+namespace Assimp {
+namespace FBX {
+
+using namespace Util;
+
+// ------------------------------------------------------------------------------------------------
+Geometry::Geometry(uint64_t id, const Element& element, const std::string& name, const Document& doc)
+    : Object(id, element, name)
+    , skin()
+{
+    const std::vector<const Connection*>& conns = doc.GetConnectionsByDestinationSequenced(ID(),"Deformer");
+    for(const Connection* con : conns) {
+        const Skin* const sk = ProcessSimpleConnection<Skin>(*con, false, "Skin -> Geometry", element);
+        if(sk) {
+            skin = sk;
+        }
+        const BlendShape* const bsp = ProcessSimpleConnection<BlendShape>(*con, false, "BlendShape -> Geometry", element);
+        if (bsp) {
+            blendShapes.push_back(bsp);
+        }
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+Geometry::~Geometry()
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+const std::vector<const BlendShape*>& Geometry::GetBlendShapes() const {
+    return blendShapes;
+}
+
+// ------------------------------------------------------------------------------------------------
+const Skin* Geometry::DeformerSkin() const {
+    return skin;
+}
+
+// ------------------------------------------------------------------------------------------------
+MeshGeometry::MeshGeometry(uint64_t id, const Element& element, const std::string& name, const Document& doc)
+: Geometry(id, element,name, doc)
+{
+    const Scope* sc = element.Compound();
+    if (!sc) {
+        DOMError("failed to read Geometry object (class: Mesh), no data scope found");
+    }
+
+    // must have Mesh elements:
+    const Element& Vertices = GetRequiredElement(*sc,"Vertices",&element);
+    const Element& PolygonVertexIndex = GetRequiredElement(*sc,"PolygonVertexIndex",&element);
+
+    // optional Mesh elements:
+    const ElementCollection& Layer = sc->GetCollection("Layer");
+
+    std::vector<aiVector3D> tempVerts;
+    ParseVectorDataArray(tempVerts,Vertices);
+
+    if(tempVerts.empty()) {
+        FBXImporter::LogWarn("encountered mesh with no vertices");
+        return;
+    }
+
+    std::vector<int> tempFaces;
+    ParseVectorDataArray(tempFaces,PolygonVertexIndex);
+
+    if(tempFaces.empty()) {
+        FBXImporter::LogWarn("encountered mesh with no faces");
+        return;
+    }
+
+    m_vertices.reserve(tempFaces.size());
+    m_faces.reserve(tempFaces.size() / 3);
+
+    m_mapping_offsets.resize(tempVerts.size());
+    m_mapping_counts.resize(tempVerts.size(),0);
+    m_mappings.resize(tempFaces.size());
+
+    const size_t vertex_count = tempVerts.size();
+
+    // generate output vertices, computing an adjacency table to
+    // preserve the mapping from fbx indices to *this* indexing.
+    unsigned int count = 0;
+    for(int index : tempFaces) {
+        const int absi = index < 0 ? (-index - 1) : index;
+        if(static_cast<size_t>(absi) >= vertex_count) {
+            DOMError("polygon vertex index out of range",&PolygonVertexIndex);
+        }
+
+        m_vertices.push_back(tempVerts[absi]);
+        ++count;
+
+        ++m_mapping_counts[absi];
+
+        if (index < 0) {
+            m_faces.push_back(count);
+            count = 0;
+        }
+    }
+
+    unsigned int cursor = 0;
+    for (size_t i = 0, e = tempVerts.size(); i < e; ++i) {
+        m_mapping_offsets[i] = cursor;
+        cursor += m_mapping_counts[i];
+
+        m_mapping_counts[i] = 0;
+    }
+
+    cursor = 0;
+    for(int index : tempFaces) {
+        const int absi = index < 0 ? (-index - 1) : index;
+        m_mappings[m_mapping_offsets[absi] + m_mapping_counts[absi]++] = cursor++;
+    }
+
+    // if settings.readAllLayers is true:
+    //  * read all layers, try to load as many vertex channels as possible
+    // if settings.readAllLayers is false:
+    //  * read only the layer with index 0, but warn about any further layers
+    for (ElementMap::const_iterator it = Layer.first; it != Layer.second; ++it) {
+        const TokenList& tokens = (*it).second->Tokens();
+
+        const char* err;
+        const int index = ParseTokenAsInt(*tokens[0], err);
+        if(err) {
+            DOMError(err,&element);
+        }
+
+        if(doc.Settings().readAllLayers || index == 0) {
+            const Scope& layer = GetRequiredScope(*(*it).second);
+            ReadLayer(layer);
+        }
+        else {
+            FBXImporter::LogWarn("ignoring additional geometry layers");
+        }
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+MeshGeometry::~MeshGeometry() {
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+const std::vector<aiVector3D>& MeshGeometry::GetVertices() const {
+    return m_vertices;
+}
+
+// ------------------------------------------------------------------------------------------------
+const std::vector<aiVector3D>& MeshGeometry::GetNormals() const {
+    return m_normals;
+}
+
+// ------------------------------------------------------------------------------------------------
+const std::vector<aiVector3D>& MeshGeometry::GetTangents() const {
+    return m_tangents;
+}
+
+// ------------------------------------------------------------------------------------------------
+const std::vector<aiVector3D>& MeshGeometry::GetBinormals() const {
+    return m_binormals;
+}
+
+// ------------------------------------------------------------------------------------------------
+const std::vector<unsigned int>& MeshGeometry::GetFaceIndexCounts() const {
+    return m_faces;
+}
+
+// ------------------------------------------------------------------------------------------------
+const std::vector<aiVector2D>& MeshGeometry::GetTextureCoords( unsigned int index ) const {
+    static const std::vector<aiVector2D> empty;
+    return index >= AI_MAX_NUMBER_OF_TEXTURECOORDS ? empty : m_uvs[ index ];
+}
+
+std::string MeshGeometry::GetTextureCoordChannelName( unsigned int index ) const {
+    return index >= AI_MAX_NUMBER_OF_TEXTURECOORDS ? "" : m_uvNames[ index ];
+}
+
+const std::vector<aiColor4D>& MeshGeometry::GetVertexColors( unsigned int index ) const {
+    static const std::vector<aiColor4D> empty;
+    return index >= AI_MAX_NUMBER_OF_COLOR_SETS ? empty : m_colors[ index ];
+}
+
+const MatIndexArray& MeshGeometry::GetMaterialIndices() const {
+    return m_materials;
+}
+// ------------------------------------------------------------------------------------------------
+const unsigned int* MeshGeometry::ToOutputVertexIndex( unsigned int in_index, unsigned int& count ) const {
+    if ( in_index >= m_mapping_counts.size() ) {
+        return NULL;
+    }
+
+    ai_assert( m_mapping_counts.size() == m_mapping_offsets.size() );
+    count = m_mapping_counts[ in_index ];
+
+    ai_assert( m_mapping_offsets[ in_index ] + count <= m_mappings.size() );
+
+    return &m_mappings[ m_mapping_offsets[ in_index ] ];
+}
+
+// ------------------------------------------------------------------------------------------------
+unsigned int MeshGeometry::FaceForVertexIndex( unsigned int in_index ) const {
+    ai_assert( in_index < m_vertices.size() );
+
+    // in the current conversion pattern this will only be needed if
+    // weights are present, so no need to always pre-compute this table
+    if ( m_facesVertexStartIndices.empty() ) {
+        m_facesVertexStartIndices.resize( m_faces.size() + 1, 0 );
+
+        std::partial_sum( m_faces.begin(), m_faces.end(), m_facesVertexStartIndices.begin() + 1 );
+        m_facesVertexStartIndices.pop_back();
+    }
+
+    ai_assert( m_facesVertexStartIndices.size() == m_faces.size() );
+    const std::vector<unsigned int>::iterator it = std::upper_bound(
+        m_facesVertexStartIndices.begin(),
+        m_facesVertexStartIndices.end(),
+        in_index
+        );
+
+    return static_cast< unsigned int >( std::distance( m_facesVertexStartIndices.begin(), it - 1 ) );
+}
+
+// ------------------------------------------------------------------------------------------------
+void MeshGeometry::ReadLayer(const Scope& layer)
+{
+    const ElementCollection& LayerElement = layer.GetCollection("LayerElement");
+    for (ElementMap::const_iterator eit = LayerElement.first; eit != LayerElement.second; ++eit) {
+        const Scope& elayer = GetRequiredScope(*(*eit).second);
+
+        ReadLayerElement(elayer);
+    }
+}
+
+
+// ------------------------------------------------------------------------------------------------
+void MeshGeometry::ReadLayerElement(const Scope& layerElement)
+{
+    const Element& Type = GetRequiredElement(layerElement,"Type");
+    const Element& TypedIndex = GetRequiredElement(layerElement,"TypedIndex");
+
+    const std::string& type = ParseTokenAsString(GetRequiredToken(Type,0));
+    const int typedIndex = ParseTokenAsInt(GetRequiredToken(TypedIndex,0));
+
+    const Scope& top = GetRequiredScope(element);
+    const ElementCollection candidates = top.GetCollection(type);
+
+    for (ElementMap::const_iterator it = candidates.first; it != candidates.second; ++it) {
+        const int index = ParseTokenAsInt(GetRequiredToken(*(*it).second,0));
+        if(index == typedIndex) {
+            ReadVertexData(type,typedIndex,GetRequiredScope(*(*it).second));
+            return;
+        }
+    }
+
+    FBXImporter::LogError(Formatter::format("failed to resolve vertex layer element: ")
+        << type << ", index: " << typedIndex);
+}
+
+// ------------------------------------------------------------------------------------------------
+void MeshGeometry::ReadVertexData(const std::string& type, int index, const Scope& source)
+{
+    const std::string& MappingInformationType = ParseTokenAsString(GetRequiredToken(
+        GetRequiredElement(source,"MappingInformationType"),0)
+    );
+
+    const std::string& ReferenceInformationType = ParseTokenAsString(GetRequiredToken(
+        GetRequiredElement(source,"ReferenceInformationType"),0)
+    );
+
+    if (type == "LayerElementUV") {
+        if(index >= AI_MAX_NUMBER_OF_TEXTURECOORDS) {
+            FBXImporter::LogError(Formatter::format("ignoring UV layer, maximum number of UV channels exceeded: ")
+                << index << " (limit is " << AI_MAX_NUMBER_OF_TEXTURECOORDS << ")" );
+            return;
+        }
+
+        const Element* Name = source["Name"];
+        m_uvNames[index] = "";
+        if(Name) {
+            m_uvNames[index] = ParseTokenAsString(GetRequiredToken(*Name,0));
+        }
+
+        ReadVertexDataUV(m_uvs[index],source,
+            MappingInformationType,
+            ReferenceInformationType
+        );
+    }
+    else if (type == "LayerElementMaterial") {
+        if (m_materials.size() > 0) {
+            FBXImporter::LogError("ignoring additional material layer");
+            return;
+        }
+
+        std::vector<int> temp_materials;
+
+        ReadVertexDataMaterials(temp_materials,source,
+            MappingInformationType,
+            ReferenceInformationType
+        );
+
+        // sometimes, there will be only negative entries. Drop the material
+        // layer in such a case (I guess it means a default material should
+        // be used). This is what the converter would do anyway, and it
+        // avoids losing the material if there are more material layers
+        // coming of which at least one contains actual data (did observe
+        // that with one test file).
+        const size_t count_neg = std::count_if(temp_materials.begin(),temp_materials.end(),[](int n) { return n < 0; });
+        if(count_neg == temp_materials.size()) {
+            FBXImporter::LogWarn("ignoring dummy material layer (all entries -1)");
+            return;
+        }
+
+        std::swap(temp_materials, m_materials);
+    }
+    else if (type == "LayerElementNormal") {
+        if (m_normals.size() > 0) {
+            FBXImporter::LogError("ignoring additional normal layer");
+            return;
+        }
+
+        ReadVertexDataNormals(m_normals,source,
+            MappingInformationType,
+            ReferenceInformationType
+        );
+    }
+    else if (type == "LayerElementTangent") {
+        if (m_tangents.size() > 0) {
+            FBXImporter::LogError("ignoring additional tangent layer");
+            return;
+        }
+
+        ReadVertexDataTangents(m_tangents,source,
+            MappingInformationType,
+            ReferenceInformationType
+        );
+    }
+    else if (type == "LayerElementBinormal") {
+        if (m_binormals.size() > 0) {
+            FBXImporter::LogError("ignoring additional binormal layer");
+            return;
+        }
+
+        ReadVertexDataBinormals(m_binormals,source,
+            MappingInformationType,
+            ReferenceInformationType
+        );
+    }
+    else if (type == "LayerElementColor") {
+        if(index >= AI_MAX_NUMBER_OF_COLOR_SETS) {
+            FBXImporter::LogError(Formatter::format("ignoring vertex color layer, maximum number of color sets exceeded: ")
+                << index << " (limit is " << AI_MAX_NUMBER_OF_COLOR_SETS << ")" );
+            return;
+        }
+
+        ReadVertexDataColors(m_colors[index],source,
+            MappingInformationType,
+            ReferenceInformationType
+        );
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+// Lengthy utility function to read and resolve a FBX vertex data array - that is, the
+// output is in polygon vertex order. This logic is used for reading normals, UVs, colors,
+// tangents ..
+template <typename T>
+void ResolveVertexDataArray(std::vector<T>& data_out, const Scope& source,
+    const std::string& MappingInformationType,
+    const std::string& ReferenceInformationType,
+    const char* dataElementName,
+    const char* indexDataElementName,
+    size_t vertex_count,
+    const std::vector<unsigned int>& mapping_counts,
+    const std::vector<unsigned int>& mapping_offsets,
+    const std::vector<unsigned int>& mappings)
+{
+    bool isDirect = ReferenceInformationType == "Direct";
+    bool isIndexToDirect = ReferenceInformationType == "IndexToDirect";
+
+    // fall-back to direct data if there is no index data element
+    if ( isIndexToDirect && !HasElement( source, indexDataElementName ) ) {
+        isDirect = true;
+        isIndexToDirect = false;
+    }
+
+    // handle permutations of Mapping and Reference type - it would be nice to
+    // deal with this more elegantly and with less redundancy, but right
+    // now it seems unavoidable.
+    if (MappingInformationType == "ByVertice" && isDirect) {
+        if (!HasElement(source, dataElementName)) {
+            return;
+        }
+        std::vector<T> tempData;
+		ParseVectorDataArray(tempData, GetRequiredElement(source, dataElementName));
+
+        data_out.resize(vertex_count);
+		for (size_t i = 0, e = tempData.size(); i < e; ++i) {
+
+            const unsigned int istart = mapping_offsets[i], iend = istart + mapping_counts[i];
+            for (unsigned int j = istart; j < iend; ++j) {
+				data_out[mappings[j]] = tempData[i];
+            }
+        }
+    }
+    else if (MappingInformationType == "ByVertice" && isIndexToDirect) {
+		std::vector<T> tempData;
+		ParseVectorDataArray(tempData, GetRequiredElement(source, dataElementName));
+
+        data_out.resize(vertex_count);
+
+        std::vector<int> uvIndices;
+        ParseVectorDataArray(uvIndices,GetRequiredElement(source,indexDataElementName));
+        for (size_t i = 0, e = uvIndices.size(); i < e; ++i) {
+
+            const unsigned int istart = mapping_offsets[i], iend = istart + mapping_counts[i];
+            for (unsigned int j = istart; j < iend; ++j) {
+				if (static_cast<size_t>(uvIndices[i]) >= tempData.size()) {
+                    DOMError("index out of range",&GetRequiredElement(source,indexDataElementName));
+                }
+				data_out[mappings[j]] = tempData[uvIndices[i]];
+            }
+        }
+    }
+    else if (MappingInformationType == "ByPolygonVertex" && isDirect) {
+		std::vector<T> tempData;
+		ParseVectorDataArray(tempData, GetRequiredElement(source, dataElementName));
+
+		if (tempData.size() != vertex_count) {
+            FBXImporter::LogError(Formatter::format("length of input data unexpected for ByPolygon mapping: ")
+				<< tempData.size() << ", expected " << vertex_count
+            );
+            return;
+        }
+
+		data_out.swap(tempData);
+    }
+    else if (MappingInformationType == "ByPolygonVertex" && isIndexToDirect) {
+		std::vector<T> tempData;
+		ParseVectorDataArray(tempData, GetRequiredElement(source, dataElementName));
+
+        data_out.resize(vertex_count);
+
+        std::vector<int> uvIndices;
+        ParseVectorDataArray(uvIndices,GetRequiredElement(source,indexDataElementName));
+
+        if (uvIndices.size() != vertex_count) {
+            FBXImporter::LogError("length of input data unexpected for ByPolygonVertex mapping");
+            return;
+        }
+
+        const T empty;
+        unsigned int next = 0;
+        for(int i : uvIndices) {
+            if ( -1 == i ) {
+                data_out[ next++ ] = empty;
+                continue;
+            }
+            if (static_cast<size_t>(i) >= tempData.size()) {
+                DOMError("index out of range",&GetRequiredElement(source,indexDataElementName));
+            }
+
+			data_out[next++] = tempData[i];
+        }
+    }
+    else {
+        FBXImporter::LogError(Formatter::format("ignoring vertex data channel, access type not implemented: ")
+            << MappingInformationType << "," << ReferenceInformationType);
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+void MeshGeometry::ReadVertexDataNormals(std::vector<aiVector3D>& normals_out, const Scope& source,
+    const std::string& MappingInformationType,
+    const std::string& ReferenceInformationType)
+{
+    ResolveVertexDataArray(normals_out,source,MappingInformationType,ReferenceInformationType,
+        "Normals",
+        "NormalsIndex",
+        m_vertices.size(),
+        m_mapping_counts,
+        m_mapping_offsets,
+        m_mappings);
+}
+
+// ------------------------------------------------------------------------------------------------
+void MeshGeometry::ReadVertexDataUV(std::vector<aiVector2D>& uv_out, const Scope& source,
+    const std::string& MappingInformationType,
+    const std::string& ReferenceInformationType)
+{
+    ResolveVertexDataArray(uv_out,source,MappingInformationType,ReferenceInformationType,
+        "UV",
+        "UVIndex",
+        m_vertices.size(),
+        m_mapping_counts,
+        m_mapping_offsets,
+        m_mappings);
+}
+
+// ------------------------------------------------------------------------------------------------
+void MeshGeometry::ReadVertexDataColors(std::vector<aiColor4D>& colors_out, const Scope& source,
+    const std::string& MappingInformationType,
+    const std::string& ReferenceInformationType)
+{
+    ResolveVertexDataArray(colors_out,source,MappingInformationType,ReferenceInformationType,
+        "Colors",
+        "ColorIndex",
+        m_vertices.size(),
+        m_mapping_counts,
+        m_mapping_offsets,
+        m_mappings);
+}
+
+// ------------------------------------------------------------------------------------------------
+static const char *TangentIndexToken = "TangentIndex";
+static const char *TangentsIndexToken = "TangentsIndex";
+
+void MeshGeometry::ReadVertexDataTangents(std::vector<aiVector3D>& tangents_out, const Scope& source,
+    const std::string& MappingInformationType,
+    const std::string& ReferenceInformationType)
+{
+    const char * str = source.Elements().count( "Tangents" ) > 0 ? "Tangents" : "Tangent";
+    const char * strIdx = source.Elements().count( "Tangents" ) > 0 ? TangentsIndexToken : TangentIndexToken;
+    ResolveVertexDataArray(tangents_out,source,MappingInformationType,ReferenceInformationType,
+        str,
+        strIdx,
+        m_vertices.size(),
+        m_mapping_counts,
+        m_mapping_offsets,
+        m_mappings);
+}
+
+// ------------------------------------------------------------------------------------------------
+static const std::string BinormalIndexToken = "BinormalIndex";
+static const std::string BinormalsIndexToken = "BinormalsIndex";
+
+void MeshGeometry::ReadVertexDataBinormals(std::vector<aiVector3D>& binormals_out, const Scope& source,
+    const std::string& MappingInformationType,
+    const std::string& ReferenceInformationType)
+{
+    const char * str = source.Elements().count( "Binormals" ) > 0 ? "Binormals" : "Binormal";
+    const char * strIdx = source.Elements().count( "Binormals" ) > 0 ? BinormalsIndexToken.c_str() : BinormalIndexToken.c_str();
+    ResolveVertexDataArray(binormals_out,source,MappingInformationType,ReferenceInformationType,
+        str,
+        strIdx,
+        m_vertices.size(),
+        m_mapping_counts,
+        m_mapping_offsets,
+        m_mappings);
+}
+
+
+// ------------------------------------------------------------------------------------------------
+void MeshGeometry::ReadVertexDataMaterials(std::vector<int>& materials_out, const Scope& source,
+    const std::string& MappingInformationType,
+    const std::string& ReferenceInformationType)
+{
+    const size_t face_count = m_faces.size();
+    ai_assert(face_count);
+
+    // materials are handled separately. First of all, they are assigned per-face
+    // and not per polyvert. Secondly, ReferenceInformationType=IndexToDirect
+    // has a slightly different meaning for materials.
+    ParseVectorDataArray(materials_out,GetRequiredElement(source,"Materials"));
+
+    if (MappingInformationType == "AllSame") {
+        // easy - same material for all faces
+        if (materials_out.empty()) {
+            FBXImporter::LogError(Formatter::format("expected material index, ignoring"));
+            return;
+        }
+        else if (materials_out.size() > 1) {
+            FBXImporter::LogWarn(Formatter::format("expected only a single material index, ignoring all except the first one"));
+            materials_out.clear();
+        }
+
+        materials_out.resize(m_vertices.size());
+        std::fill(materials_out.begin(), materials_out.end(), materials_out.at(0));
+    }
+    else if (MappingInformationType == "ByPolygon" && ReferenceInformationType == "IndexToDirect") {
+        materials_out.resize(face_count);
+
+        if(materials_out.size() != face_count) {
+            FBXImporter::LogError(Formatter::format("length of input data unexpected for ByPolygon mapping: ")
+                << materials_out.size() << ", expected " << face_count
+            );
+            return;
+        }
+    }
+    else {
+        FBXImporter::LogError(Formatter::format("ignoring material assignments, access type not implemented: ")
+            << MappingInformationType << "," << ReferenceInformationType);
+    }
+}
+// ------------------------------------------------------------------------------------------------
+ShapeGeometry::ShapeGeometry(uint64_t id, const Element& element, const std::string& name, const Document& doc)
+    : Geometry(id, element, name, doc)
+{
+    const Scope* sc = element.Compound();
+    if (!sc) {
+        DOMError("failed to read Geometry object (class: Shape), no data scope found");
+    }
+    const Element& Indexes = GetRequiredElement(*sc, "Indexes", &element);
+    const Element& Normals = GetRequiredElement(*sc, "Normals", &element);
+    const Element& Vertices = GetRequiredElement(*sc, "Vertices", &element);
+    ParseVectorDataArray(m_indices, Indexes);
+    ParseVectorDataArray(m_vertices, Vertices);
+    ParseVectorDataArray(m_normals, Normals);
+}
+
+// ------------------------------------------------------------------------------------------------
+ShapeGeometry::~ShapeGeometry() {
+    // empty
+}
+// ------------------------------------------------------------------------------------------------
+const std::vector<aiVector3D>& ShapeGeometry::GetVertices() const {
+    return m_vertices;
+}
+// ------------------------------------------------------------------------------------------------
+const std::vector<aiVector3D>& ShapeGeometry::GetNormals() const {
+    return m_normals;
+}
+// ------------------------------------------------------------------------------------------------
+const std::vector<unsigned int>& ShapeGeometry::GetIndices() const {
+    return m_indices;
+}
+// ------------------------------------------------------------------------------------------------
+LineGeometry::LineGeometry(uint64_t id, const Element& element, const std::string& name, const Document& doc)
+    : Geometry(id, element, name, doc)
+{
+    const Scope* sc = element.Compound();
+    if (!sc) {
+        DOMError("failed to read Geometry object (class: Line), no data scope found");
+    }
+    const Element& Points = GetRequiredElement(*sc, "Points", &element);
+    const Element& PointsIndex = GetRequiredElement(*sc, "PointsIndex", &element);
+    ParseVectorDataArray(m_vertices, Points);
+    ParseVectorDataArray(m_indices, PointsIndex);
+}
+
+// ------------------------------------------------------------------------------------------------
+LineGeometry::~LineGeometry() {
+    // empty
+}
+// ------------------------------------------------------------------------------------------------
+const std::vector<aiVector3D>& LineGeometry::GetVertices() const {
+    return m_vertices;
+}
+// ------------------------------------------------------------------------------------------------
+const std::vector<int>& LineGeometry::GetIndices() const {
+    return m_indices;
+}
+} // !FBX
+} // !Assimp
+#endif
+
diff --git a/thirdparty/assimp/code/FBX/FBXMeshGeometry.h b/thirdparty/assimp/code/FBX/FBXMeshGeometry.h
new file mode 100644
index 0000000000..d6d4512177
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXMeshGeometry.h
@@ -0,0 +1,235 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+copyright notice, this list of conditions and the
+following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other
+materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+contributors may be used to endorse or promote products
+derived from this software without specific prior
+written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXImporter.h
+*  @brief Declaration of the FBX main importer class
+*/
+#ifndef INCLUDED_AI_FBX_MESHGEOMETRY_H
+#define INCLUDED_AI_FBX_MESHGEOMETRY_H
+
+#include "FBXParser.h"
+#include "FBXDocument.h"
+
+namespace Assimp {
+namespace FBX {
+
+/** 
+ *  DOM base class for all kinds of FBX geometry 
+ */
+class Geometry : public Object
+{
+public:
+    Geometry( uint64_t id, const Element& element, const std::string& name, const Document& doc );
+    virtual ~Geometry();
+
+    /** Get the Skin attached to this geometry or NULL */
+    const Skin* DeformerSkin() const;
+
+    /** Get the BlendShape attached to this geometry or NULL */
+    const std::vector<const BlendShape*>& GetBlendShapes() const;
+
+private:
+    const Skin* skin;
+    std::vector<const BlendShape*> blendShapes;
+
+};
+
+typedef std::vector<int> MatIndexArray;
+
+
+/** 
+ *  DOM class for FBX geometry of type "Mesh"
+ */
+class MeshGeometry : public Geometry
+{
+public:
+    /** The class constructor */
+    MeshGeometry( uint64_t id, const Element& element, const std::string& name, const Document& doc );
+    
+    /** The class destructor */
+    virtual ~MeshGeometry();
+
+    /** Get a list of all vertex points, non-unique*/
+    const std::vector<aiVector3D>& GetVertices() const;
+
+    /** Get a list of all vertex normals or an empty array if
+    *  no normals are specified. */
+    const std::vector<aiVector3D>& GetNormals() const;
+
+    /** Get a list of all vertex tangents or an empty array
+    *  if no tangents are specified */
+    const std::vector<aiVector3D>& GetTangents() const;
+
+    /** Get a list of all vertex bi-normals or an empty array
+    *  if no bi-normals are specified */
+    const std::vector<aiVector3D>& GetBinormals() const;
+
+    /** Return list of faces - each entry denotes a face and specifies
+    *  how many vertices it has. Vertices are taken from the
+    *  vertex data arrays in sequential order. */
+    const std::vector<unsigned int>& GetFaceIndexCounts() const;
+
+    /** Get a UV coordinate slot, returns an empty array if
+    *  the requested slot does not exist. */
+    const std::vector<aiVector2D>& GetTextureCoords( unsigned int index ) const;
+
+    /** Get a UV coordinate slot, returns an empty array if
+    *  the requested slot does not exist. */
+    std::string GetTextureCoordChannelName( unsigned int index ) const;
+
+    /** Get a vertex color coordinate slot, returns an empty array if
+    *  the requested slot does not exist. */
+    const std::vector<aiColor4D>& GetVertexColors( unsigned int index ) const;
+
+    /** Get per-face-vertex material assignments */
+    const MatIndexArray& GetMaterialIndices() const;
+
+    /** Convert from a fbx file vertex index (for example from a #Cluster weight) or NULL
+    * if the vertex index is not valid. */
+    const unsigned int* ToOutputVertexIndex( unsigned int in_index, unsigned int& count ) const;
+
+    /** Determine the face to which a particular output vertex index belongs.
+    *  This mapping is always unique. */
+    unsigned int FaceForVertexIndex( unsigned int in_index ) const;
+private:
+    void ReadLayer( const Scope& layer );
+    void ReadLayerElement( const Scope& layerElement );
+    void ReadVertexData( const std::string& type, int index, const Scope& source );
+
+    void ReadVertexDataUV( std::vector<aiVector2D>& uv_out, const Scope& source,
+        const std::string& MappingInformationType,
+        const std::string& ReferenceInformationType );
+
+    void ReadVertexDataNormals( std::vector<aiVector3D>& normals_out, const Scope& source,
+        const std::string& MappingInformationType,
+        const std::string& ReferenceInformationType );
+
+    void ReadVertexDataColors( std::vector<aiColor4D>& colors_out, const Scope& source,
+        const std::string& MappingInformationType,
+        const std::string& ReferenceInformationType );
+
+    void ReadVertexDataTangents( std::vector<aiVector3D>& tangents_out, const Scope& source,
+        const std::string& MappingInformationType,
+        const std::string& ReferenceInformationType );
+
+    void ReadVertexDataBinormals( std::vector<aiVector3D>& binormals_out, const Scope& source,
+        const std::string& MappingInformationType,
+        const std::string& ReferenceInformationType );
+
+    void ReadVertexDataMaterials( MatIndexArray& materials_out, const Scope& source,
+        const std::string& MappingInformationType,
+        const std::string& ReferenceInformationType );
+
+private:
+    // cached data arrays
+    MatIndexArray m_materials;
+    std::vector<aiVector3D> m_vertices;
+    std::vector<unsigned int> m_faces;
+    mutable std::vector<unsigned int> m_facesVertexStartIndices;
+    std::vector<aiVector3D> m_tangents;
+    std::vector<aiVector3D> m_binormals;
+    std::vector<aiVector3D> m_normals;
+
+    std::string m_uvNames[ AI_MAX_NUMBER_OF_TEXTURECOORDS ];
+    std::vector<aiVector2D> m_uvs[ AI_MAX_NUMBER_OF_TEXTURECOORDS ];
+    std::vector<aiColor4D> m_colors[ AI_MAX_NUMBER_OF_COLOR_SETS ];
+
+    std::vector<unsigned int> m_mapping_counts;
+    std::vector<unsigned int> m_mapping_offsets;
+    std::vector<unsigned int> m_mappings;
+};
+
+/**
+*  DOM class for FBX geometry of type "Shape"
+*/
+class ShapeGeometry : public Geometry
+{
+public:
+    /** The class constructor */
+    ShapeGeometry(uint64_t id, const Element& element, const std::string& name, const Document& doc);
+
+    /** The class destructor */
+    virtual ~ShapeGeometry();
+
+    /** Get a list of all vertex points, non-unique*/
+    const std::vector<aiVector3D>& GetVertices() const;
+
+    /** Get a list of all vertex normals or an empty array if
+    *  no normals are specified. */
+    const std::vector<aiVector3D>& GetNormals() const;
+
+    /** Return list of vertex indices. */
+    const std::vector<unsigned int>& GetIndices() const;
+
+private:
+    std::vector<aiVector3D> m_vertices;
+    std::vector<aiVector3D> m_normals;
+    std::vector<unsigned int> m_indices;
+};
+/**
+*  DOM class for FBX geometry of type "Line"
+*/
+class LineGeometry : public Geometry
+{
+public:
+    /** The class constructor */
+    LineGeometry(uint64_t id, const Element& element, const std::string& name, const Document& doc);
+
+    /** The class destructor */
+    virtual ~LineGeometry();
+
+    /** Get a list of all vertex points, non-unique*/
+    const std::vector<aiVector3D>& GetVertices() const;
+
+    /** Return list of vertex indices. */
+    const std::vector<int>& GetIndices() const;
+
+private:
+    std::vector<aiVector3D> m_vertices;
+    std::vector<int> m_indices;
+};
+
+}
+}
+
+#endif // INCLUDED_AI_FBX_MESHGEOMETRY_H
+
diff --git a/thirdparty/assimp/code/FBX/FBXModel.cpp b/thirdparty/assimp/code/FBX/FBXModel.cpp
new file mode 100644
index 0000000000..589af36ac7
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXModel.cpp
@@ -0,0 +1,153 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXModel.cpp
+ *  @brief Assimp::FBX::Model implementation
+ */
+
+#ifndef ASSIMP_BUILD_NO_FBX_IMPORTER
+
+#include "FBXParser.h"
+#include "FBXMeshGeometry.h"
+#include "FBXDocument.h"
+#include "FBXImporter.h"
+#include "FBXDocumentUtil.h"
+
+namespace Assimp {
+namespace FBX {
+
+using namespace Util;
+
+// ------------------------------------------------------------------------------------------------
+Model::Model(uint64_t id, const Element& element, const Document& doc, const std::string& name)
+    : Object(id,element,name)
+    , shading("Y")
+{
+    const Scope& sc = GetRequiredScope(element);
+    const Element* const Shading = sc["Shading"];
+    const Element* const Culling = sc["Culling"];
+
+    if(Shading) {
+        shading = GetRequiredToken(*Shading,0).StringContents();
+    }
+
+    if (Culling) {
+        culling = ParseTokenAsString(GetRequiredToken(*Culling,0));
+    }
+
+    props = GetPropertyTable(doc,"Model.FbxNode",element,sc);
+    ResolveLinks(element,doc);
+}
+
+// ------------------------------------------------------------------------------------------------
+Model::~Model()
+{
+
+}
+
+// ------------------------------------------------------------------------------------------------
+void Model::ResolveLinks(const Element& element, const Document& doc)
+{
+    const char* const arr[] = {"Geometry","Material","NodeAttribute"};
+
+    // resolve material
+    const std::vector<const Connection*>& conns = doc.GetConnectionsByDestinationSequenced(ID(),arr, 3);
+
+    materials.reserve(conns.size());
+    geometry.reserve(conns.size());
+    attributes.reserve(conns.size());
+    for(const Connection* con : conns) {
+
+        // material and geometry links should be Object-Object connections
+        if (con->PropertyName().length()) {
+            continue;
+        }
+
+        const Object* const ob = con->SourceObject();
+        if(!ob) {
+            DOMWarning("failed to read source object for incoming Model link, ignoring",&element);
+            continue;
+        }
+
+        const Material* const mat = dynamic_cast<const Material*>(ob);
+        if(mat) {
+            materials.push_back(mat);
+            continue;
+        }
+
+        const Geometry* const geo = dynamic_cast<const Geometry*>(ob);
+        if(geo) {
+            geometry.push_back(geo);
+            continue;
+        }
+
+        const NodeAttribute* const att = dynamic_cast<const NodeAttribute*>(ob);
+        if(att) {
+            attributes.push_back(att);
+            continue;
+        }
+
+        DOMWarning("source object for model link is neither Material, NodeAttribute nor Geometry, ignoring",&element);
+        continue;
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+bool Model::IsNull() const
+{
+    const std::vector<const NodeAttribute*>& attrs = GetAttributes();
+    for(const NodeAttribute* att : attrs) {
+
+        const Null* null_tag = dynamic_cast<const Null*>(att);
+        if(null_tag) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+
+} //!FBX
+} //!Assimp
+
+#endif
diff --git a/thirdparty/assimp/code/FBX/FBXNodeAttribute.cpp b/thirdparty/assimp/code/FBX/FBXNodeAttribute.cpp
new file mode 100644
index 0000000000..b72e5637ee
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXNodeAttribute.cpp
@@ -0,0 +1,170 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXNoteAttribute.cpp
+ *  @brief Assimp::FBX::NodeAttribute (and subclasses) implementation
+ */
+
+#ifndef ASSIMP_BUILD_NO_FBX_IMPORTER
+
+#include "FBXParser.h"
+#include "FBXDocument.h"
+#include "FBXImporter.h"
+#include "FBXDocumentUtil.h"
+
+namespace Assimp {
+namespace FBX {
+
+using namespace Util;
+
+// ------------------------------------------------------------------------------------------------
+NodeAttribute::NodeAttribute(uint64_t id, const Element& element, const Document& doc, const std::string& name)
+: Object(id,element,name)
+, props()
+{
+    const Scope& sc = GetRequiredScope(element);
+
+    const std::string& classname = ParseTokenAsString(GetRequiredToken(element,2));
+
+    // hack on the deriving type but Null/LimbNode attributes are the only case in which
+    // the property table is by design absent and no warning should be generated
+    // for it.
+    const bool is_null_or_limb = !strcmp(classname.c_str(), "Null") || !strcmp(classname.c_str(), "LimbNode");
+    props = GetPropertyTable(doc,"NodeAttribute.Fbx" + classname,element,sc, is_null_or_limb);
+}
+
+
+// ------------------------------------------------------------------------------------------------
+NodeAttribute::~NodeAttribute()
+{
+    // empty
+}
+
+
+// ------------------------------------------------------------------------------------------------
+CameraSwitcher::CameraSwitcher(uint64_t id, const Element& element, const Document& doc, const std::string& name)
+    : NodeAttribute(id,element,doc,name)
+{
+    const Scope& sc = GetRequiredScope(element);
+    const Element* const CameraId = sc["CameraId"];
+    const Element* const CameraName = sc["CameraName"];
+    const Element* const CameraIndexName = sc["CameraIndexName"];
+
+    if(CameraId) {
+        cameraId = ParseTokenAsInt(GetRequiredToken(*CameraId,0));
+    }
+
+    if(CameraName) {
+        cameraName = GetRequiredToken(*CameraName,0).StringContents();
+    }
+
+    if(CameraIndexName && CameraIndexName->Tokens().size()) {
+        cameraIndexName = GetRequiredToken(*CameraIndexName,0).StringContents();
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+CameraSwitcher::~CameraSwitcher()
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+Camera::Camera(uint64_t id, const Element& element, const Document& doc, const std::string& name)
+: NodeAttribute(id,element,doc,name)
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+Camera::~Camera()
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+Light::Light(uint64_t id, const Element& element, const Document& doc, const std::string& name)
+: NodeAttribute(id,element,doc,name)
+{
+    // empty
+}
+
+
+// ------------------------------------------------------------------------------------------------
+Light::~Light()
+{
+}
+
+
+// ------------------------------------------------------------------------------------------------
+Null::Null(uint64_t id, const Element& element, const Document& doc, const std::string& name)
+: NodeAttribute(id,element,doc,name)
+{
+
+}
+
+
+// ------------------------------------------------------------------------------------------------
+Null::~Null()
+{
+
+}
+
+
+// ------------------------------------------------------------------------------------------------
+LimbNode::LimbNode(uint64_t id, const Element& element, const Document& doc, const std::string& name)
+: NodeAttribute(id,element,doc,name)
+{
+
+}
+
+
+// ------------------------------------------------------------------------------------------------
+LimbNode::~LimbNode()
+{
+
+}
+
+}
+}
+
+#endif
diff --git a/thirdparty/assimp/code/FBX/FBXParser.cpp b/thirdparty/assimp/code/FBX/FBXParser.cpp
new file mode 100644
index 0000000000..4a9346040d
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXParser.cpp
@@ -0,0 +1,1309 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXParser.cpp
+ *  @brief Implementation of the FBX parser and the rudimentary DOM that we use
+ */
+
+#ifndef ASSIMP_BUILD_NO_FBX_IMPORTER
+
+#ifdef ASSIMP_BUILD_NO_OWN_ZLIB
+#   include <zlib.h>
+#else
+#   include "../contrib/zlib/zlib.h"
+#endif
+
+#include "FBXTokenizer.h"
+#include "FBXParser.h"
+#include "FBXUtil.h"
+
+#include <assimp/ParsingUtils.h>
+#include <assimp/fast_atof.h>
+#include <assimp/ByteSwapper.h>
+
+#include <iostream>
+
+using namespace Assimp;
+using namespace Assimp::FBX;
+
+namespace {
+
+    // ------------------------------------------------------------------------------------------------
+    // signal parse error, this is always unrecoverable. Throws DeadlyImportError.
+    AI_WONT_RETURN void ParseError(const std::string& message, const Token& token) AI_WONT_RETURN_SUFFIX;
+    AI_WONT_RETURN void ParseError(const std::string& message, const Token& token)
+    {
+        throw DeadlyImportError(Util::AddTokenText("FBX-Parser",message,&token));
+    }
+
+    // ------------------------------------------------------------------------------------------------
+    AI_WONT_RETURN void ParseError(const std::string& message, const Element* element = NULL) AI_WONT_RETURN_SUFFIX;
+    AI_WONT_RETURN void ParseError(const std::string& message, const Element* element)
+    {
+        if(element) {
+            ParseError(message,element->KeyToken());
+        }
+        throw DeadlyImportError("FBX-Parser " + message);
+    }
+
+
+    // ------------------------------------------------------------------------------------------------
+    void ParseError(const std::string& message, TokenPtr token)
+    {
+        if(token) {
+            ParseError(message, *token);
+        }
+        ParseError(message);
+    }
+
+    // Initially, we did reinterpret_cast, breaking strict aliasing rules.
+    // This actually caused trouble on Android, so let's be safe this time.
+    // https://github.com/assimp/assimp/issues/24
+    template <typename T>
+    T SafeParse(const char* data, const char* end) {
+        // Actual size validation happens during Tokenization so
+        // this is valid as an assertion.
+        (void)(end);
+        ai_assert(static_cast<size_t>(end - data) >= sizeof(T));
+        T result = static_cast<T>(0);
+        ::memcpy(&result, data, sizeof(T));
+        return result;
+    }
+}
+
+namespace Assimp {
+namespace FBX {
+
+// ------------------------------------------------------------------------------------------------
+Element::Element(const Token& key_token, Parser& parser)
+: key_token(key_token)
+{
+    TokenPtr n = nullptr;
+    do {
+        n = parser.AdvanceToNextToken();
+        if(!n) {
+            ParseError("unexpected end of file, expected closing bracket",parser.LastToken());
+        }
+
+        if (n->Type() == TokenType_DATA) {
+            tokens.push_back(n);
+			TokenPtr prev = n;
+            n = parser.AdvanceToNextToken();
+            if(!n) {
+                ParseError("unexpected end of file, expected bracket, comma or key",parser.LastToken());
+            }
+
+			const TokenType ty = n->Type();
+
+			// some exporters are missing a comma on the next line
+			if (ty == TokenType_DATA && prev->Type() == TokenType_DATA && (n->Line() == prev->Line() + 1)) {
+				tokens.push_back(n);
+				continue;
+			}
+
+            if (ty != TokenType_OPEN_BRACKET && ty != TokenType_CLOSE_BRACKET && ty != TokenType_COMMA && ty != TokenType_KEY) {
+                ParseError("unexpected token; expected bracket, comma or key",n);
+            }
+        }
+
+        if (n->Type() == TokenType_OPEN_BRACKET) {
+            compound.reset(new Scope(parser));
+
+            // current token should be a TOK_CLOSE_BRACKET
+            n = parser.CurrentToken();
+            ai_assert(n);
+
+            if (n->Type() != TokenType_CLOSE_BRACKET) {
+                ParseError("expected closing bracket",n);
+            }
+
+            parser.AdvanceToNextToken();
+            return;
+        }
+    }
+    while(n->Type() != TokenType_KEY && n->Type() != TokenType_CLOSE_BRACKET);
+}
+
+// ------------------------------------------------------------------------------------------------
+Element::~Element()
+{
+     // no need to delete tokens, they are owned by the parser
+}
+
+// ------------------------------------------------------------------------------------------------
+Scope::Scope(Parser& parser,bool topLevel)
+{
+    if(!topLevel) {
+        TokenPtr t = parser.CurrentToken();
+        if (t->Type() != TokenType_OPEN_BRACKET) {
+            ParseError("expected open bracket",t);
+        }
+    }
+
+    TokenPtr n = parser.AdvanceToNextToken();
+    if(n == NULL) {
+        ParseError("unexpected end of file");
+    }
+
+    // note: empty scopes are allowed
+    while(n->Type() != TokenType_CLOSE_BRACKET) {
+        if (n->Type() != TokenType_KEY) {
+            ParseError("unexpected token, expected TOK_KEY",n);
+        }
+
+        const std::string& str = n->StringContents();
+        elements.insert(ElementMap::value_type(str,new_Element(*n,parser)));
+
+        // Element() should stop at the next Key token (or right after a Close token)
+        n = parser.CurrentToken();
+        if(n == NULL) {
+            if (topLevel) {
+                return;
+            }
+            ParseError("unexpected end of file",parser.LastToken());
+        }
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+Scope::~Scope()
+{
+    for(ElementMap::value_type& v : elements) {
+        delete v.second;
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+Parser::Parser (const TokenList& tokens, bool is_binary)
+: tokens(tokens)
+, last()
+, current()
+, cursor(tokens.begin())
+, is_binary(is_binary)
+{
+    root.reset(new Scope(*this,true));
+}
+
+// ------------------------------------------------------------------------------------------------
+Parser::~Parser()
+{
+    // empty
+}
+
+// ------------------------------------------------------------------------------------------------
+TokenPtr Parser::AdvanceToNextToken()
+{
+    last = current;
+    if (cursor == tokens.end()) {
+        current = NULL;
+    } else {
+        current = *cursor++;
+    }
+    return current;
+}
+
+// ------------------------------------------------------------------------------------------------
+TokenPtr Parser::CurrentToken() const
+{
+    return current;
+}
+
+// ------------------------------------------------------------------------------------------------
+TokenPtr Parser::LastToken() const
+{
+    return last;
+}
+
+// ------------------------------------------------------------------------------------------------
+uint64_t ParseTokenAsID(const Token& t, const char*& err_out)
+{
+    err_out = NULL;
+
+    if (t.Type() != TokenType_DATA) {
+        err_out = "expected TOK_DATA token";
+        return 0L;
+    }
+
+    if(t.IsBinary())
+    {
+        const char* data = t.begin();
+        if (data[0] != 'L') {
+            err_out = "failed to parse ID, unexpected data type, expected L(ong) (binary)";
+            return 0L;
+        }
+
+        BE_NCONST uint64_t id = SafeParse<uint64_t>(data+1, t.end());
+        AI_SWAP8(id);
+        return id;
+    }
+
+    // XXX: should use size_t here
+    unsigned int length = static_cast<unsigned int>(t.end() - t.begin());
+    ai_assert(length > 0);
+
+    const char* out = nullptr;
+    const uint64_t id = strtoul10_64(t.begin(),&out,&length);
+    if (out > t.end()) {
+        err_out = "failed to parse ID (text)";
+        return 0L;
+    }
+
+    return id;
+}
+
+// ------------------------------------------------------------------------------------------------
+size_t ParseTokenAsDim(const Token& t, const char*& err_out)
+{
+    // same as ID parsing, except there is a trailing asterisk
+    err_out = NULL;
+
+    if (t.Type() != TokenType_DATA) {
+        err_out = "expected TOK_DATA token";
+        return 0;
+    }
+
+    if(t.IsBinary())
+    {
+        const char* data = t.begin();
+        if (data[0] != 'L') {
+            err_out = "failed to parse ID, unexpected data type, expected L(ong) (binary)";
+            return 0;
+        }
+
+        BE_NCONST uint64_t id = SafeParse<uint64_t>(data+1, t.end());
+        AI_SWAP8(id);
+        return static_cast<size_t>(id);
+    }
+
+    if(*t.begin() != '*') {
+        err_out = "expected asterisk before array dimension";
+        return 0;
+    }
+
+    // XXX: should use size_t here
+    unsigned int length = static_cast<unsigned int>(t.end() - t.begin());
+    if(length == 0) {
+        err_out = "expected valid integer number after asterisk";
+        return 0;
+    }
+
+    const char* out = nullptr;
+    const size_t id = static_cast<size_t>(strtoul10_64(t.begin() + 1,&out,&length));
+    if (out > t.end()) {
+        err_out = "failed to parse ID";
+        return 0;
+    }
+
+    return id;
+}
+
+
+// ------------------------------------------------------------------------------------------------
+float ParseTokenAsFloat(const Token& t, const char*& err_out)
+{
+    err_out = NULL;
+
+    if (t.Type() != TokenType_DATA) {
+        err_out = "expected TOK_DATA token";
+        return 0.0f;
+    }
+
+    if(t.IsBinary())
+    {
+        const char* data = t.begin();
+        if (data[0] != 'F' && data[0] != 'D') {
+            err_out = "failed to parse F(loat) or D(ouble), unexpected data type (binary)";
+            return 0.0f;
+        }
+
+        if (data[0] == 'F') {
+            return SafeParse<float>(data+1, t.end());
+        }
+        else {
+            return static_cast<float>( SafeParse<double>(data+1, t.end()) );
+        }
+    }
+
+    // need to copy the input string to a temporary buffer
+    // first - next in the fbx token stream comes ',',
+    // which fast_atof could interpret as decimal point.
+#define MAX_FLOAT_LENGTH 31
+    char temp[MAX_FLOAT_LENGTH + 1];
+    const size_t length = static_cast<size_t>(t.end()-t.begin());
+    std::copy(t.begin(),t.end(),temp);
+    temp[std::min(static_cast<size_t>(MAX_FLOAT_LENGTH),length)] = '\0';
+
+    return fast_atof(temp);
+}
+
+
+// ------------------------------------------------------------------------------------------------
+int ParseTokenAsInt(const Token& t, const char*& err_out)
+{
+    err_out = NULL;
+
+    if (t.Type() != TokenType_DATA) {
+        err_out = "expected TOK_DATA token";
+        return 0;
+    }
+
+    if(t.IsBinary())
+    {
+        const char* data = t.begin();
+        if (data[0] != 'I') {
+            err_out = "failed to parse I(nt), unexpected data type (binary)";
+            return 0;
+        }
+
+        BE_NCONST int32_t ival = SafeParse<int32_t>(data+1, t.end());
+        AI_SWAP4(ival);
+        return static_cast<int>(ival);
+    }
+
+    ai_assert(static_cast<size_t>(t.end() - t.begin()) > 0);
+
+    const char* out;
+    const int intval = strtol10(t.begin(),&out);
+    if (out != t.end()) {
+        err_out = "failed to parse ID";
+        return 0;
+    }
+
+    return intval;
+}
+
+
+// ------------------------------------------------------------------------------------------------
+int64_t ParseTokenAsInt64(const Token& t, const char*& err_out)
+{
+    err_out = NULL;
+
+    if (t.Type() != TokenType_DATA) {
+        err_out = "expected TOK_DATA token";
+        return 0L;
+    }
+
+    if (t.IsBinary())
+    {
+        const char* data = t.begin();
+        if (data[0] != 'L') {
+            err_out = "failed to parse Int64, unexpected data type";
+            return 0L;
+        }
+
+        BE_NCONST int64_t id = SafeParse<int64_t>(data + 1, t.end());
+        AI_SWAP8(id);
+        return id;
+    }
+
+    // XXX: should use size_t here
+    unsigned int length = static_cast<unsigned int>(t.end() - t.begin());
+    ai_assert(length > 0);
+
+    const char* out = nullptr;
+    const int64_t id = strtol10_64(t.begin(), &out, &length);
+    if (out > t.end()) {
+        err_out = "failed to parse Int64 (text)";
+        return 0L;
+    }
+
+    return id;
+}
+
+// ------------------------------------------------------------------------------------------------
+std::string ParseTokenAsString(const Token& t, const char*& err_out)
+{
+    err_out = NULL;
+
+    if (t.Type() != TokenType_DATA) {
+        err_out = "expected TOK_DATA token";
+        return "";
+    }
+
+    if(t.IsBinary())
+    {
+        const char* data = t.begin();
+        if (data[0] != 'S') {
+            err_out = "failed to parse S(tring), unexpected data type (binary)";
+            return "";
+        }
+
+        // read string length
+        BE_NCONST int32_t len = SafeParse<int32_t>(data+1, t.end());
+        AI_SWAP4(len);
+
+        ai_assert(t.end() - data == 5 + len);
+        return std::string(data + 5, len);
+    }
+
+    const size_t length = static_cast<size_t>(t.end() - t.begin());
+    if(length < 2) {
+        err_out = "token is too short to hold a string";
+        return "";
+    }
+
+    const char* s = t.begin(), *e = t.end() - 1;
+    if (*s != '\"' || *e != '\"') {
+        err_out = "expected double quoted string";
+        return "";
+    }
+
+    return std::string(s+1,length-2);
+}
+
+
+namespace {
+
+// ------------------------------------------------------------------------------------------------
+// read the type code and element count of a binary data array and stop there
+void ReadBinaryDataArrayHead(const char*& data, const char* end, char& type, uint32_t& count,
+    const Element& el)
+{
+    if (static_cast<size_t>(end-data) < 5) {
+        ParseError("binary data array is too short, need five (5) bytes for type signature and element count",&el);
+    }
+
+    // data type
+    type = *data;
+
+    // read number of elements
+    BE_NCONST uint32_t len = SafeParse<uint32_t>(data+1, end);
+    AI_SWAP4(len);
+
+    count = len;
+    data += 5;
+}
+
+
+// ------------------------------------------------------------------------------------------------
+// read binary data array, assume cursor points to the 'compression mode' field (i.e. behind the header)
+void ReadBinaryDataArray(char type, uint32_t count, const char*& data, const char* end,
+    std::vector<char>& buff,
+    const Element& /*el*/)
+{
+    BE_NCONST uint32_t encmode = SafeParse<uint32_t>(data, end);
+    AI_SWAP4(encmode);
+    data += 4;
+
+    // next comes the compressed length
+    BE_NCONST uint32_t comp_len = SafeParse<uint32_t>(data, end);
+    AI_SWAP4(comp_len);
+    data += 4;
+
+    ai_assert(data + comp_len == end);
+
+    // determine the length of the uncompressed data by looking at the type signature
+    uint32_t stride = 0;
+    switch(type)
+    {
+        case 'f':
+        case 'i':
+            stride = 4;
+            break;
+
+        case 'd':
+        case 'l':
+            stride = 8;
+            break;
+
+        default:
+            ai_assert(false);
+    };
+
+    const uint32_t full_length = stride * count;
+    buff.resize(full_length);
+
+    if(encmode == 0) {
+        ai_assert(full_length == comp_len);
+
+        // plain data, no compression
+        std::copy(data, end, buff.begin());
+    }
+    else if(encmode == 1) {
+        // zlib/deflate, next comes ZIP head (0x78 0x01)
+        // see http://www.ietf.org/rfc/rfc1950.txt
+
+        z_stream zstream;
+        zstream.opaque = Z_NULL;
+        zstream.zalloc = Z_NULL;
+        zstream.zfree  = Z_NULL;
+        zstream.data_type = Z_BINARY;
+
+        // http://hewgill.com/journal/entries/349-how-to-decompress-gzip-stream-with-zlib
+        if(Z_OK != inflateInit(&zstream)) {
+            ParseError("failure initializing zlib");
+        }
+
+        zstream.next_in   = reinterpret_cast<Bytef*>( const_cast<char*>(data) );
+        zstream.avail_in  = comp_len;
+
+        zstream.avail_out = static_cast<uInt>(buff.size());
+        zstream.next_out = reinterpret_cast<Bytef*>(&*buff.begin());
+        const int ret = inflate(&zstream, Z_FINISH);
+
+        if (ret != Z_STREAM_END && ret != Z_OK) {
+            ParseError("failure decompressing compressed data section");
+        }
+
+        // terminate zlib
+        inflateEnd(&zstream);
+    }
+#ifdef ASSIMP_BUILD_DEBUG
+    else {
+        // runtime check for this happens at tokenization stage
+        ai_assert(false);
+    }
+#endif
+
+    data += comp_len;
+    ai_assert(data == end);
+}
+
+} // !anon
+
+
+// ------------------------------------------------------------------------------------------------
+// read an array of float3 tuples
+void ParseVectorDataArray(std::vector<aiVector3D>& out, const Element& el)
+{
+    out.resize( 0 );
+
+    const TokenList& tok = el.Tokens();
+    if(tok.empty()) {
+        ParseError("unexpected empty element",&el);
+    }
+
+    if(tok[0]->IsBinary()) {
+        const char* data = tok[0]->begin(), *end = tok[0]->end();
+
+        char type;
+        uint32_t count;
+        ReadBinaryDataArrayHead(data, end, type, count, el);
+
+        if(count % 3 != 0) {
+            ParseError("number of floats is not a multiple of three (3) (binary)",&el);
+        }
+
+        if(!count) {
+            return;
+        }
+
+        if (type != 'd' && type != 'f') {
+            ParseError("expected float or double array (binary)",&el);
+        }
+
+        std::vector<char> buff;
+        ReadBinaryDataArray(type, count, data, end, buff, el);
+
+        ai_assert(data == end);
+        ai_assert(buff.size() == count * (type == 'd' ? 8 : 4));
+
+        const uint32_t count3 = count / 3;
+        out.reserve(count3);
+
+        if (type == 'd') {
+            const double* d = reinterpret_cast<const double*>(&buff[0]);
+            for (unsigned int i = 0; i < count3; ++i, d += 3) {
+                out.push_back(aiVector3D(static_cast<ai_real>(d[0]),
+                    static_cast<ai_real>(d[1]),
+                    static_cast<ai_real>(d[2])));
+            }
+            // for debugging
+            /*for ( size_t i = 0; i < out.size(); i++ ) {
+                aiVector3D vec3( out[ i ] );
+                std::stringstream stream;
+                stream << " vec3.x = " << vec3.x << " vec3.y = " << vec3.y << " vec3.z = " << vec3.z << std::endl;
+                DefaultLogger::get()->info( stream.str() );
+            }*/
+        }
+        else if (type == 'f') {
+            const float* f = reinterpret_cast<const float*>(&buff[0]);
+            for (unsigned int i = 0; i < count3; ++i, f += 3) {
+                out.push_back(aiVector3D(f[0],f[1],f[2]));
+            }
+        }
+
+        return;
+    }
+
+    const size_t dim = ParseTokenAsDim(*tok[0]);
+
+    // may throw bad_alloc if the input is rubbish, but this need
+    // not to be prevented - importing would fail but we wouldn't
+    // crash since assimp handles this case properly.
+    out.reserve(dim);
+
+    const Scope& scope = GetRequiredScope(el);
+    const Element& a = GetRequiredElement(scope,"a",&el);
+
+    if (a.Tokens().size() % 3 != 0) {
+        ParseError("number of floats is not a multiple of three (3)",&el);
+    }
+    for (TokenList::const_iterator it = a.Tokens().begin(), end = a.Tokens().end(); it != end; ) {
+        aiVector3D v;
+        v.x = ParseTokenAsFloat(**it++);
+        v.y = ParseTokenAsFloat(**it++);
+        v.z = ParseTokenAsFloat(**it++);
+
+        out.push_back(v);
+    }
+}
+
+
+// ------------------------------------------------------------------------------------------------
+// read an array of color4 tuples
+void ParseVectorDataArray(std::vector<aiColor4D>& out, const Element& el)
+{
+    out.resize( 0 );
+    const TokenList& tok = el.Tokens();
+    if(tok.empty()) {
+        ParseError("unexpected empty element",&el);
+    }
+
+    if(tok[0]->IsBinary()) {
+        const char* data = tok[0]->begin(), *end = tok[0]->end();
+
+        char type;
+        uint32_t count;
+        ReadBinaryDataArrayHead(data, end, type, count, el);
+
+        if(count % 4 != 0) {
+            ParseError("number of floats is not a multiple of four (4) (binary)",&el);
+        }
+
+        if(!count) {
+            return;
+        }
+
+        if (type != 'd' && type != 'f') {
+            ParseError("expected float or double array (binary)",&el);
+        }
+
+        std::vector<char> buff;
+        ReadBinaryDataArray(type, count, data, end, buff, el);
+
+        ai_assert(data == end);
+        ai_assert(buff.size() == count * (type == 'd' ? 8 : 4));
+
+        const uint32_t count4 = count / 4;
+        out.reserve(count4);
+
+        if (type == 'd') {
+            const double* d = reinterpret_cast<const double*>(&buff[0]);
+            for (unsigned int i = 0; i < count4; ++i, d += 4) {
+                out.push_back(aiColor4D(static_cast<float>(d[0]),
+                    static_cast<float>(d[1]),
+                    static_cast<float>(d[2]),
+                    static_cast<float>(d[3])));
+            }
+        }
+        else if (type == 'f') {
+            const float* f = reinterpret_cast<const float*>(&buff[0]);
+            for (unsigned int i = 0; i < count4; ++i, f += 4) {
+                out.push_back(aiColor4D(f[0],f[1],f[2],f[3]));
+            }
+        }
+        return;
+    }
+
+    const size_t dim = ParseTokenAsDim(*tok[0]);
+
+    //  see notes in ParseVectorDataArray() above
+    out.reserve(dim);
+
+    const Scope& scope = GetRequiredScope(el);
+    const Element& a = GetRequiredElement(scope,"a",&el);
+
+    if (a.Tokens().size() % 4 != 0) {
+        ParseError("number of floats is not a multiple of four (4)",&el);
+    }
+    for (TokenList::const_iterator it = a.Tokens().begin(), end = a.Tokens().end(); it != end; ) {
+        aiColor4D v;
+        v.r = ParseTokenAsFloat(**it++);
+        v.g = ParseTokenAsFloat(**it++);
+        v.b = ParseTokenAsFloat(**it++);
+        v.a = ParseTokenAsFloat(**it++);
+
+        out.push_back(v);
+    }
+}
+
+
+// ------------------------------------------------------------------------------------------------
+// read an array of float2 tuples
+void ParseVectorDataArray(std::vector<aiVector2D>& out, const Element& el)
+{
+    out.resize( 0 );
+    const TokenList& tok = el.Tokens();
+    if(tok.empty()) {
+        ParseError("unexpected empty element",&el);
+    }
+
+    if(tok[0]->IsBinary()) {
+        const char* data = tok[0]->begin(), *end = tok[0]->end();
+
+        char type;
+        uint32_t count;
+        ReadBinaryDataArrayHead(data, end, type, count, el);
+
+        if(count % 2 != 0) {
+            ParseError("number of floats is not a multiple of two (2) (binary)",&el);
+        }
+
+        if(!count) {
+            return;
+        }
+
+        if (type != 'd' && type != 'f') {
+            ParseError("expected float or double array (binary)",&el);
+        }
+
+        std::vector<char> buff;
+        ReadBinaryDataArray(type, count, data, end, buff, el);
+
+        ai_assert(data == end);
+        ai_assert(buff.size() == count * (type == 'd' ? 8 : 4));
+
+        const uint32_t count2 = count / 2;
+        out.reserve(count2);
+
+        if (type == 'd') {
+            const double* d = reinterpret_cast<const double*>(&buff[0]);
+            for (unsigned int i = 0; i < count2; ++i, d += 2) {
+                out.push_back(aiVector2D(static_cast<float>(d[0]),
+                    static_cast<float>(d[1])));
+            }
+        }
+        else if (type == 'f') {
+            const float* f = reinterpret_cast<const float*>(&buff[0]);
+            for (unsigned int i = 0; i < count2; ++i, f += 2) {
+                out.push_back(aiVector2D(f[0],f[1]));
+            }
+        }
+
+        return;
+    }
+
+    const size_t dim = ParseTokenAsDim(*tok[0]);
+
+    // see notes in ParseVectorDataArray() above
+    out.reserve(dim);
+
+    const Scope& scope = GetRequiredScope(el);
+    const Element& a = GetRequiredElement(scope,"a",&el);
+
+    if (a.Tokens().size() % 2 != 0) {
+        ParseError("number of floats is not a multiple of two (2)",&el);
+    }
+    for (TokenList::const_iterator it = a.Tokens().begin(), end = a.Tokens().end(); it != end; ) {
+        aiVector2D v;
+        v.x = ParseTokenAsFloat(**it++);
+        v.y = ParseTokenAsFloat(**it++);
+
+        out.push_back(v);
+    }
+}
+
+
+// ------------------------------------------------------------------------------------------------
+// read an array of ints
+void ParseVectorDataArray(std::vector<int>& out, const Element& el)
+{
+    out.resize( 0 );
+    const TokenList& tok = el.Tokens();
+    if(tok.empty()) {
+        ParseError("unexpected empty element",&el);
+    }
+
+    if(tok[0]->IsBinary()) {
+        const char* data = tok[0]->begin(), *end = tok[0]->end();
+
+        char type;
+        uint32_t count;
+        ReadBinaryDataArrayHead(data, end, type, count, el);
+
+        if(!count) {
+            return;
+        }
+
+        if (type != 'i') {
+            ParseError("expected int array (binary)",&el);
+        }
+
+        std::vector<char> buff;
+        ReadBinaryDataArray(type, count, data, end, buff, el);
+
+        ai_assert(data == end);
+        ai_assert(buff.size() == count * 4);
+
+        out.reserve(count);
+
+        const int32_t* ip = reinterpret_cast<const int32_t*>(&buff[0]);
+        for (unsigned int i = 0; i < count; ++i, ++ip) {
+            BE_NCONST int32_t val = *ip;
+            AI_SWAP4(val);
+            out.push_back(val);
+        }
+
+        return;
+    }
+
+    const size_t dim = ParseTokenAsDim(*tok[0]);
+
+    // see notes in ParseVectorDataArray()
+    out.reserve(dim);
+
+    const Scope& scope = GetRequiredScope(el);
+    const Element& a = GetRequiredElement(scope,"a",&el);
+
+    for (TokenList::const_iterator it = a.Tokens().begin(), end = a.Tokens().end(); it != end; ) {
+        const int ival = ParseTokenAsInt(**it++);
+        out.push_back(ival);
+    }
+}
+
+
+// ------------------------------------------------------------------------------------------------
+// read an array of floats
+void ParseVectorDataArray(std::vector<float>& out, const Element& el)
+{
+    out.resize( 0 );
+    const TokenList& tok = el.Tokens();
+    if(tok.empty()) {
+        ParseError("unexpected empty element",&el);
+    }
+
+    if(tok[0]->IsBinary()) {
+        const char* data = tok[0]->begin(), *end = tok[0]->end();
+
+        char type;
+        uint32_t count;
+        ReadBinaryDataArrayHead(data, end, type, count, el);
+
+        if(!count) {
+            return;
+        }
+
+        if (type != 'd' && type != 'f') {
+            ParseError("expected float or double array (binary)",&el);
+        }
+
+        std::vector<char> buff;
+        ReadBinaryDataArray(type, count, data, end, buff, el);
+
+        ai_assert(data == end);
+        ai_assert(buff.size() == count * (type == 'd' ? 8 : 4));
+
+        if (type == 'd') {
+            const double* d = reinterpret_cast<const double*>(&buff[0]);
+            for (unsigned int i = 0; i < count; ++i, ++d) {
+                out.push_back(static_cast<float>(*d));
+            }
+        }
+        else if (type == 'f') {
+            const float* f = reinterpret_cast<const float*>(&buff[0]);
+            for (unsigned int i = 0; i < count; ++i, ++f) {
+                out.push_back(*f);
+            }
+        }
+
+        return;
+    }
+
+    const size_t dim = ParseTokenAsDim(*tok[0]);
+
+    // see notes in ParseVectorDataArray()
+    out.reserve(dim);
+
+    const Scope& scope = GetRequiredScope(el);
+    const Element& a = GetRequiredElement(scope,"a",&el);
+
+    for (TokenList::const_iterator it = a.Tokens().begin(), end = a.Tokens().end(); it != end; ) {
+        const float ival = ParseTokenAsFloat(**it++);
+        out.push_back(ival);
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+// read an array of uints
+void ParseVectorDataArray(std::vector<unsigned int>& out, const Element& el)
+{
+    out.resize( 0 );
+    const TokenList& tok = el.Tokens();
+    if(tok.empty()) {
+        ParseError("unexpected empty element",&el);
+    }
+
+    if(tok[0]->IsBinary()) {
+        const char* data = tok[0]->begin(), *end = tok[0]->end();
+
+        char type;
+        uint32_t count;
+        ReadBinaryDataArrayHead(data, end, type, count, el);
+
+        if(!count) {
+            return;
+        }
+
+        if (type != 'i') {
+            ParseError("expected (u)int array (binary)",&el);
+        }
+
+        std::vector<char> buff;
+        ReadBinaryDataArray(type, count, data, end, buff, el);
+
+        ai_assert(data == end);
+        ai_assert(buff.size() == count * 4);
+
+        out.reserve(count);
+
+        const int32_t* ip = reinterpret_cast<const int32_t*>(&buff[0]);
+        for (unsigned int i = 0; i < count; ++i, ++ip) {
+            BE_NCONST int32_t val = *ip;
+            if(val < 0) {
+                ParseError("encountered negative integer index (binary)");
+            }
+
+            AI_SWAP4(val);
+            out.push_back(val);
+        }
+
+        return;
+    }
+
+    const size_t dim = ParseTokenAsDim(*tok[0]);
+
+    // see notes in ParseVectorDataArray()
+    out.reserve(dim);
+
+    const Scope& scope = GetRequiredScope(el);
+    const Element& a = GetRequiredElement(scope,"a",&el);
+
+    for (TokenList::const_iterator it = a.Tokens().begin(), end = a.Tokens().end(); it != end; ) {
+        const int ival = ParseTokenAsInt(**it++);
+        if(ival < 0) {
+            ParseError("encountered negative integer index");
+        }
+        out.push_back(static_cast<unsigned int>(ival));
+    }
+}
+
+
+// ------------------------------------------------------------------------------------------------
+// read an array of uint64_ts
+void ParseVectorDataArray(std::vector<uint64_t>& out, const Element& el)
+{
+    out.resize( 0 );
+    const TokenList& tok = el.Tokens();
+    if(tok.empty()) {
+        ParseError("unexpected empty element",&el);
+    }
+
+    if(tok[0]->IsBinary()) {
+        const char* data = tok[0]->begin(), *end = tok[0]->end();
+
+        char type;
+        uint32_t count;
+        ReadBinaryDataArrayHead(data, end, type, count, el);
+
+        if(!count) {
+            return;
+        }
+
+        if (type != 'l') {
+            ParseError("expected long array (binary)",&el);
+        }
+
+        std::vector<char> buff;
+        ReadBinaryDataArray(type, count, data, end, buff, el);
+
+        ai_assert(data == end);
+        ai_assert(buff.size() == count * 8);
+
+        out.reserve(count);
+
+        const uint64_t* ip = reinterpret_cast<const uint64_t*>(&buff[0]);
+        for (unsigned int i = 0; i < count; ++i, ++ip) {
+            BE_NCONST uint64_t val = *ip;
+            AI_SWAP8(val);
+            out.push_back(val);
+        }
+
+        return;
+    }
+
+    const size_t dim = ParseTokenAsDim(*tok[0]);
+
+    // see notes in ParseVectorDataArray()
+    out.reserve(dim);
+
+    const Scope& scope = GetRequiredScope(el);
+    const Element& a = GetRequiredElement(scope,"a",&el);
+
+    for (TokenList::const_iterator it = a.Tokens().begin(), end = a.Tokens().end(); it != end; ) {
+        const uint64_t ival = ParseTokenAsID(**it++);
+
+        out.push_back(ival);
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+// read an array of int64_ts
+void ParseVectorDataArray(std::vector<int64_t>& out, const Element& el)
+{
+    out.resize( 0 );
+    const TokenList& tok = el.Tokens();
+    if (tok.empty()) {
+        ParseError("unexpected empty element", &el);
+    }
+
+    if (tok[0]->IsBinary()) {
+        const char* data = tok[0]->begin(), *end = tok[0]->end();
+
+        char type;
+        uint32_t count;
+        ReadBinaryDataArrayHead(data, end, type, count, el);
+
+        if (!count) {
+            return;
+        }
+
+        if (type != 'l') {
+            ParseError("expected long array (binary)", &el);
+        }
+
+        std::vector<char> buff;
+        ReadBinaryDataArray(type, count, data, end, buff, el);
+
+        ai_assert(data == end);
+        ai_assert(buff.size() == count * 8);
+
+        out.reserve(count);
+
+        const int64_t* ip = reinterpret_cast<const int64_t*>(&buff[0]);
+        for (unsigned int i = 0; i < count; ++i, ++ip) {
+            BE_NCONST int64_t val = *ip;
+            AI_SWAP8(val);
+            out.push_back(val);
+        }
+
+        return;
+    }
+
+    const size_t dim = ParseTokenAsDim(*tok[0]);
+
+    // see notes in ParseVectorDataArray()
+    out.reserve(dim);
+
+    const Scope& scope = GetRequiredScope(el);
+    const Element& a = GetRequiredElement(scope, "a", &el);
+
+    for (TokenList::const_iterator it = a.Tokens().begin(), end = a.Tokens().end(); it != end;) {
+        const int64_t ival = ParseTokenAsInt64(**it++);
+
+        out.push_back(ival);
+    }
+}
+
+// ------------------------------------------------------------------------------------------------
+aiMatrix4x4 ReadMatrix(const Element& element)
+{
+    std::vector<float> values;
+    ParseVectorDataArray(values,element);
+
+    if(values.size() != 16) {
+        ParseError("expected 16 matrix elements");
+    }
+
+    aiMatrix4x4 result;
+
+
+    result.a1 = values[0];
+    result.a2 = values[1];
+    result.a3 = values[2];
+    result.a4 = values[3];
+
+    result.b1 = values[4];
+    result.b2 = values[5];
+    result.b3 = values[6];
+    result.b4 = values[7];
+
+    result.c1 = values[8];
+    result.c2 = values[9];
+    result.c3 = values[10];
+    result.c4 = values[11];
+
+    result.d1 = values[12];
+    result.d2 = values[13];
+    result.d3 = values[14];
+    result.d4 = values[15];
+
+    result.Transpose();
+    return result;
+}
+
+
+// ------------------------------------------------------------------------------------------------
+// wrapper around ParseTokenAsString() with ParseError handling
+std::string ParseTokenAsString(const Token& t)
+{
+    const char* err;
+    const std::string& i = ParseTokenAsString(t,err);
+    if(err) {
+        ParseError(err,t);
+    }
+    return i;
+}
+
+bool HasElement( const Scope& sc, const std::string& index ) {
+    const Element* el = sc[ index ];
+    if ( nullptr == el ) {
+        return false;
+    }
+
+    return true;
+}
+
+// ------------------------------------------------------------------------------------------------
+// extract a required element from a scope, abort if the element cannot be found
+const Element& GetRequiredElement(const Scope& sc, const std::string& index, const Element* element /*= NULL*/)
+{
+    const Element* el = sc[index];
+    if(!el) {
+        ParseError("did not find required element \"" + index + "\"",element);
+    }
+    return *el;
+}
+
+
+// ------------------------------------------------------------------------------------------------
+// extract required compound scope
+const Scope& GetRequiredScope(const Element& el)
+{
+    const Scope* const s = el.Compound();
+    if(!s) {
+        ParseError("expected compound scope",&el);
+    }
+
+    return *s;
+}
+
+
+// ------------------------------------------------------------------------------------------------
+// get token at a particular index
+const Token& GetRequiredToken(const Element& el, unsigned int index)
+{
+    const TokenList& t = el.Tokens();
+    if(index >= t.size()) {
+        ParseError(Formatter::format( "missing token at index " ) << index,&el);
+    }
+
+    return *t[index];
+}
+
+
+// ------------------------------------------------------------------------------------------------
+// wrapper around ParseTokenAsID() with ParseError handling
+uint64_t ParseTokenAsID(const Token& t)
+{
+    const char* err;
+    const uint64_t i = ParseTokenAsID(t,err);
+    if(err) {
+        ParseError(err,t);
+    }
+    return i;
+}
+
+
+// ------------------------------------------------------------------------------------------------
+// wrapper around ParseTokenAsDim() with ParseError handling
+size_t ParseTokenAsDim(const Token& t)
+{
+    const char* err;
+    const size_t i = ParseTokenAsDim(t,err);
+    if(err) {
+        ParseError(err,t);
+    }
+    return i;
+}
+
+
+// ------------------------------------------------------------------------------------------------
+// wrapper around ParseTokenAsFloat() with ParseError handling
+float ParseTokenAsFloat(const Token& t)
+{
+    const char* err;
+    const float i = ParseTokenAsFloat(t,err);
+    if(err) {
+        ParseError(err,t);
+    }
+    return i;
+}
+
+// ------------------------------------------------------------------------------------------------
+// wrapper around ParseTokenAsInt() with ParseError handling
+int ParseTokenAsInt(const Token& t)
+{
+    const char* err;
+    const int i = ParseTokenAsInt(t,err);
+    if(err) {
+        ParseError(err,t);
+    }
+    return i;
+}
+
+// ------------------------------------------------------------------------------------------------
+// wrapper around ParseTokenAsInt64() with ParseError handling
+int64_t ParseTokenAsInt64(const Token& t)
+{
+    const char* err;
+    const int64_t i = ParseTokenAsInt64(t, err);
+    if (err) {
+        ParseError(err, t);
+    }
+    return i;
+}
+
+} // !FBX
+} // !Assimp
+
+#endif
diff --git a/thirdparty/assimp/code/FBX/FBXParser.h b/thirdparty/assimp/code/FBX/FBXParser.h
new file mode 100644
index 0000000000..7b0cf72039
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXParser.h
@@ -0,0 +1,235 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXParser.h
+ *  @brief FBX parsing code
+ */
+#ifndef INCLUDED_AI_FBX_PARSER_H
+#define INCLUDED_AI_FBX_PARSER_H
+
+#include <stdint.h>
+#include <map>
+#include <memory>
+#include <assimp/LogAux.h>
+#include <assimp/fast_atof.h>
+
+#include "FBXCompileConfig.h"
+#include "FBXTokenizer.h"
+
+namespace Assimp {
+namespace FBX {
+
+class Scope;
+class Parser;
+class Element;
+
+// XXX should use C++11's unique_ptr - but assimp's need to keep working with 03
+typedef std::vector< Scope* > ScopeList;
+typedef std::fbx_unordered_multimap< std::string, Element* > ElementMap;
+
+typedef std::pair<ElementMap::const_iterator,ElementMap::const_iterator> ElementCollection;
+
+#   define new_Scope new Scope
+#   define new_Element new Element
+
+
+/** FBX data entity that consists of a key:value tuple.
+ *
+ *  Example:
+ *  @verbatim
+ *    AnimationCurve: 23, "AnimCurve::", "" {
+ *        [..]
+ *    }
+ *  @endverbatim
+ *
+ *  As can be seen in this sample, elements can contain nested #Scope
+ *  as their trailing member.  **/
+class Element
+{
+public:
+    Element(const Token& key_token, Parser& parser);
+    ~Element();
+
+    const Scope* Compound() const {
+        return compound.get();
+    }
+
+    const Token& KeyToken() const {
+        return key_token;
+    }
+
+    const TokenList& Tokens() const {
+        return tokens;
+    }
+
+private:
+    const Token& key_token;
+    TokenList tokens;
+    std::unique_ptr<Scope> compound;
+};
+
+/** FBX data entity that consists of a 'scope', a collection
+ *  of not necessarily unique #Element instances.
+ *
+ *  Example:
+ *  @verbatim
+ *    GlobalSettings:  {
+ *        Version: 1000
+ *        Properties70:
+ *        [...]
+ *    }
+ *  @endverbatim  */
+class Scope
+{
+public:
+    Scope(Parser& parser, bool topLevel = false);
+    ~Scope();
+
+    const Element* operator[] (const std::string& index) const {
+        ElementMap::const_iterator it = elements.find(index);
+        return it == elements.end() ? NULL : (*it).second;
+    }
+
+	const Element* FindElementCaseInsensitive(const std::string& elementName) const {
+		const char* elementNameCStr = elementName.c_str();
+		for (auto element = elements.begin(); element != elements.end(); ++element)
+		{
+			if (!ASSIMP_strincmp(element->first.c_str(), elementNameCStr, MAXLEN)) {
+				return element->second;
+			}
+		}
+		return NULL;
+	}
+
+    ElementCollection GetCollection(const std::string& index) const {
+        return elements.equal_range(index);
+    }
+
+    const ElementMap& Elements() const  {
+        return elements;
+    }
+
+private:
+    ElementMap elements;
+};
+
+/** FBX parsing class, takes a list of input tokens and generates a hierarchy
+ *  of nested #Scope instances, representing the fbx DOM.*/
+class Parser
+{
+public:
+    /** Parse given a token list. Does not take ownership of the tokens -
+     *  the objects must persist during the entire parser lifetime */
+    Parser (const TokenList& tokens,bool is_binary);
+    ~Parser();
+
+    const Scope& GetRootScope() const {
+        return *root.get();
+    }
+
+    bool IsBinary() const {
+        return is_binary;
+    }
+
+private:
+    friend class Scope;
+    friend class Element;
+
+    TokenPtr AdvanceToNextToken();
+    TokenPtr LastToken() const;
+    TokenPtr CurrentToken() const;
+
+private:
+    const TokenList& tokens;
+
+    TokenPtr last, current;
+    TokenList::const_iterator cursor;
+    std::unique_ptr<Scope> root;
+
+    const bool is_binary;
+};
+
+
+/* token parsing - this happens when building the DOM out of the parse-tree*/
+uint64_t ParseTokenAsID(const Token& t, const char*& err_out);
+size_t ParseTokenAsDim(const Token& t, const char*& err_out);
+
+float ParseTokenAsFloat(const Token& t, const char*& err_out);
+int ParseTokenAsInt(const Token& t, const char*& err_out);
+int64_t ParseTokenAsInt64(const Token& t, const char*& err_out);
+std::string ParseTokenAsString(const Token& t, const char*& err_out);
+
+/* wrapper around ParseTokenAsXXX() with DOMError handling */
+uint64_t ParseTokenAsID(const Token& t);
+size_t ParseTokenAsDim(const Token& t);
+float ParseTokenAsFloat(const Token& t);
+int ParseTokenAsInt(const Token& t);
+int64_t ParseTokenAsInt64(const Token& t);
+std::string ParseTokenAsString(const Token& t);
+
+/* read data arrays */
+void ParseVectorDataArray(std::vector<aiVector3D>& out, const Element& el);
+void ParseVectorDataArray(std::vector<aiColor4D>& out, const Element& el);
+void ParseVectorDataArray(std::vector<aiVector2D>& out, const Element& el);
+void ParseVectorDataArray(std::vector<int>& out, const Element& el);
+void ParseVectorDataArray(std::vector<float>& out, const Element& el);
+void ParseVectorDataArray(std::vector<unsigned int>& out, const Element& el);
+void ParseVectorDataArray(std::vector<uint64_t>& out, const Element& e);
+void ParseVectorDataArray(std::vector<int64_t>& out, const Element& el);
+
+bool HasElement( const Scope& sc, const std::string& index );
+
+// extract a required element from a scope, abort if the element cannot be found
+const Element& GetRequiredElement(const Scope& sc, const std::string& index, const Element* element = NULL);
+
+// extract required compound scope
+const Scope& GetRequiredScope(const Element& el);
+// get token at a particular index
+const Token& GetRequiredToken(const Element& el, unsigned int index);
+
+// read a 4x4 matrix from an array of 16 floats
+aiMatrix4x4 ReadMatrix(const Element& element);
+
+} // ! FBX
+} // ! Assimp
+
+#endif // ! INCLUDED_AI_FBX_PARSER_H
diff --git a/thirdparty/assimp/code/FBX/FBXProperties.cpp b/thirdparty/assimp/code/FBX/FBXProperties.cpp
new file mode 100644
index 0000000000..8d7036b6a9
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXProperties.cpp
@@ -0,0 +1,235 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXProperties.cpp
+ *  @brief Implementation of the FBX dynamic properties system
+ */
+
+#ifndef ASSIMP_BUILD_NO_FBX_IMPORTER
+
+#include "FBXTokenizer.h"
+#include "FBXParser.h"
+#include "FBXDocument.h"
+#include "FBXDocumentUtil.h"
+#include "FBXProperties.h"
+
+namespace Assimp {
+namespace FBX {
+
+    using namespace Util;
+
+// ------------------------------------------------------------------------------------------------
+Property::Property()
+{
+}
+
+// ------------------------------------------------------------------------------------------------
+Property::~Property()
+{
+}
+
+namespace {
+
+// ------------------------------------------------------------------------------------------------
+// read a typed property out of a FBX element. The return value is NULL if the property cannot be read.
+Property* ReadTypedProperty(const Element& element)
+{
+    ai_assert(element.KeyToken().StringContents() == "P");
+
+    const TokenList& tok = element.Tokens();
+    ai_assert(tok.size() >= 5);
+
+    const std::string& s = ParseTokenAsString(*tok[1]);
+    const char* const cs = s.c_str();
+    if (!strcmp(cs,"KString")) {
+        return new TypedProperty<std::string>(ParseTokenAsString(*tok[4]));
+    }
+    else if (!strcmp(cs,"bool") || !strcmp(cs,"Bool")) {
+        return new TypedProperty<bool>(ParseTokenAsInt(*tok[4]) != 0);
+    }
+    else if (!strcmp(cs, "int") || !strcmp(cs, "Int") || !strcmp(cs, "enum") || !strcmp(cs, "Enum")) {
+        return new TypedProperty<int>(ParseTokenAsInt(*tok[4]));
+    }
+    else if (!strcmp(cs, "ULongLong")) {
+        return new TypedProperty<uint64_t>(ParseTokenAsID(*tok[4]));
+    }
+    else if (!strcmp(cs, "KTime")) {
+        return new TypedProperty<int64_t>(ParseTokenAsInt64(*tok[4]));
+    }
+    else if (!strcmp(cs,"Vector3D") ||
+        !strcmp(cs,"ColorRGB") ||
+        !strcmp(cs,"Vector") ||
+        !strcmp(cs,"Color") ||
+        !strcmp(cs,"Lcl Translation") ||
+        !strcmp(cs,"Lcl Rotation") ||
+        !strcmp(cs,"Lcl Scaling")
+        ) {
+        return new TypedProperty<aiVector3D>(aiVector3D(
+            ParseTokenAsFloat(*tok[4]),
+            ParseTokenAsFloat(*tok[5]),
+            ParseTokenAsFloat(*tok[6]))
+        );
+    }
+    else if (!strcmp(cs,"double") || !strcmp(cs,"Number") || !strcmp(cs,"Float") || !strcmp(cs,"FieldOfView") || !strcmp( cs, "UnitScaleFactor" ) ) {
+        return new TypedProperty<float>(ParseTokenAsFloat(*tok[4]));
+    }
+    return NULL;
+}
+
+
+// ------------------------------------------------------------------------------------------------
+// peek into an element and check if it contains a FBX property, if so return its name.
+std::string PeekPropertyName(const Element& element)
+{
+    ai_assert(element.KeyToken().StringContents() == "P");
+    const TokenList& tok = element.Tokens();
+    if(tok.size() < 4) {
+        return "";
+    }
+
+    return ParseTokenAsString(*tok[0]);
+}
+
+} //! anon
+
+
+// ------------------------------------------------------------------------------------------------
+PropertyTable::PropertyTable()
+: templateProps()
+, element()
+{
+}
+
+// ------------------------------------------------------------------------------------------------
+PropertyTable::PropertyTable(const Element& element, std::shared_ptr<const PropertyTable> templateProps)
+: templateProps(templateProps)
+, element(&element)
+{
+    const Scope& scope = GetRequiredScope(element);
+    for(const ElementMap::value_type& v : scope.Elements()) {
+        if(v.first != "P") {
+            DOMWarning("expected only P elements in property table",v.second);
+            continue;
+        }
+
+        const std::string& name = PeekPropertyName(*v.second);
+        if(!name.length()) {
+            DOMWarning("could not read property name",v.second);
+            continue;
+        }
+
+        LazyPropertyMap::const_iterator it = lazyProps.find(name);
+        if (it != lazyProps.end()) {
+            DOMWarning("duplicate property name, will hide previous value: " + name,v.second);
+            continue;
+        }
+
+        lazyProps[name] = v.second;
+    }
+}
+
+
+// ------------------------------------------------------------------------------------------------
+PropertyTable::~PropertyTable()
+{
+    for(PropertyMap::value_type& v : props) {
+        delete v.second;
+    }
+}
+
+
+// ------------------------------------------------------------------------------------------------
+const Property* PropertyTable::Get(const std::string& name) const
+{
+    PropertyMap::const_iterator it = props.find(name);
+    if (it == props.end()) {
+        // hasn't been parsed yet?
+        LazyPropertyMap::const_iterator lit = lazyProps.find(name);
+        if(lit != lazyProps.end()) {
+            props[name] = ReadTypedProperty(*(*lit).second);
+            it = props.find(name);
+
+            ai_assert(it != props.end());
+        }
+
+        if (it == props.end()) {
+            // check property template
+            if(templateProps) {
+                return templateProps->Get(name);
+            }
+
+            return NULL;
+        }
+    }
+
+    return (*it).second;
+}
+
+DirectPropertyMap PropertyTable::GetUnparsedProperties() const
+{
+    DirectPropertyMap result;
+
+    // Loop through all the lazy properties (which is all the properties)
+    for(const LazyPropertyMap::value_type& element : lazyProps) {
+
+        // Skip parsed properties
+        if (props.end() != props.find(element.first)) continue;
+
+        // Read the element's value.
+        // Wrap the naked pointer (since the call site is required to acquire ownership)
+        // std::unique_ptr from C++11 would be preferred both as a wrapper and a return value.
+        std::shared_ptr<Property> prop = std::shared_ptr<Property>(ReadTypedProperty(*element.second));
+
+        // Element could not be read. Skip it.
+        if (!prop) continue;
+
+        // Add to result
+        result[element.first] = prop;
+    }
+
+    return result;
+}
+
+} //! FBX
+} //! Assimp
+
+#endif
diff --git a/thirdparty/assimp/code/FBX/FBXProperties.h b/thirdparty/assimp/code/FBX/FBXProperties.h
new file mode 100644
index 0000000000..58755542fc
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXProperties.h
@@ -0,0 +1,185 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXProperties.h
+ *  @brief FBX dynamic properties
+ */
+#ifndef INCLUDED_AI_FBX_PROPERTIES_H
+#define INCLUDED_AI_FBX_PROPERTIES_H
+
+#include "FBXCompileConfig.h"
+#include <memory>
+#include <string>
+
+namespace Assimp {
+namespace FBX {
+
+// Forward declarations
+class Element;
+
+/** Represents a dynamic property. Type info added by deriving classes,
+ *  see #TypedProperty.
+ Example:
+ @verbatim
+   P: "ShininessExponent", "double", "Number", "",0.5
+ @endvebatim
+*/
+class Property {
+protected:
+    Property();
+
+public:
+    virtual ~Property();
+
+public:
+    template <typename T>
+    const T* As() const {
+        return dynamic_cast<const T*>(this);
+    }
+};
+
+template<typename T>
+class TypedProperty : public Property {
+public:
+    explicit TypedProperty(const T& value)
+    : value(value) {
+        // empty
+    }
+
+    const T& Value() const {
+        return value;
+    }
+
+private:
+    T value;
+};
+
+
+typedef std::fbx_unordered_map<std::string,std::shared_ptr<Property> > DirectPropertyMap;
+typedef std::fbx_unordered_map<std::string,const Property*>            PropertyMap;
+typedef std::fbx_unordered_map<std::string,const Element*>             LazyPropertyMap;
+
+/** 
+ *  Represents a property table as can be found in the newer FBX files (Properties60, Properties70)
+ */
+class PropertyTable {
+public:
+    // in-memory property table with no source element
+    PropertyTable();
+    PropertyTable(const Element& element, std::shared_ptr<const PropertyTable> templateProps);
+    ~PropertyTable();
+
+    const Property* Get(const std::string& name) const;
+
+    // PropertyTable's need not be coupled with FBX elements so this can be NULL
+    const Element* GetElement() const {
+        return element;
+    }
+
+    const PropertyTable* TemplateProps() const {
+        return templateProps.get();
+    }
+
+    DirectPropertyMap GetUnparsedProperties() const;
+
+private:
+    LazyPropertyMap lazyProps;
+    mutable PropertyMap props;
+    const std::shared_ptr<const PropertyTable> templateProps;
+    const Element* const element;
+};
+
+// ------------------------------------------------------------------------------------------------
+template <typename T>
+inline 
+T PropertyGet(const PropertyTable& in, const std::string& name, const T& defaultValue) {
+    const Property* const prop = in.Get(name);
+    if( nullptr == prop) {
+        return defaultValue;
+    }
+
+    // strong typing, no need to be lenient
+    const TypedProperty<T>* const tprop = prop->As< TypedProperty<T> >();
+    if( nullptr == tprop) {
+        return defaultValue;
+    }
+
+    return tprop->Value();
+}
+
+// ------------------------------------------------------------------------------------------------
+template <typename T>
+inline 
+T PropertyGet(const PropertyTable& in, const std::string& name, bool& result, bool useTemplate=false ) {
+    const Property* prop = in.Get(name);
+    if( nullptr == prop) {
+        if ( ! useTemplate ) {
+            result = false;
+            return T();
+        }
+        const PropertyTable* templ = in.TemplateProps();
+        if ( nullptr == templ ) {
+            result = false;
+            return T();
+        }
+        prop = templ->Get(name);
+        if ( nullptr == prop ) {
+            result = false;
+            return T();
+        }
+    }
+
+    // strong typing, no need to be lenient
+    const TypedProperty<T>* const tprop = prop->As< TypedProperty<T> >();
+    if( nullptr == tprop) {
+        result = false;
+        return T();
+    }
+
+    result = true;
+    return tprop->Value();
+}
+
+} //! FBX
+} //! Assimp
+
+#endif // INCLUDED_AI_FBX_PROPERTIES_H
diff --git a/thirdparty/assimp/code/FBX/FBXTokenizer.cpp b/thirdparty/assimp/code/FBX/FBXTokenizer.cpp
new file mode 100644
index 0000000000..252cce3557
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXTokenizer.cpp
@@ -0,0 +1,248 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXTokenizer.cpp
+ *  @brief Implementation of the FBX broadphase lexer
+ */
+
+#ifndef ASSIMP_BUILD_NO_FBX_IMPORTER
+
+// tab width for logging columns
+#define ASSIMP_FBX_TAB_WIDTH 4
+
+#include <assimp/ParsingUtils.h>
+
+#include "FBXTokenizer.h"
+#include "FBXUtil.h"
+#include <assimp/Exceptional.h>
+
+namespace Assimp {
+namespace FBX {
+
+// ------------------------------------------------------------------------------------------------
+Token::Token(const char* sbegin, const char* send, TokenType type, unsigned int line, unsigned int column)
+    :
+#ifdef DEBUG
+    contents(sbegin, static_cast<size_t>(send-sbegin)),
+#endif
+    sbegin(sbegin)
+    , send(send)
+    , type(type)
+    , line(line)
+    , column(column)
+{
+    ai_assert(sbegin);
+    ai_assert(send);
+
+    // tokens must be of non-zero length
+    ai_assert(static_cast<size_t>(send-sbegin) > 0);
+}
+
+// ------------------------------------------------------------------------------------------------
+Token::~Token()
+{
+}
+
+namespace {
+
+// ------------------------------------------------------------------------------------------------
+// signal tokenization error, this is always unrecoverable. Throws DeadlyImportError.
+AI_WONT_RETURN void TokenizeError(const std::string& message, unsigned int line, unsigned int column) AI_WONT_RETURN_SUFFIX;
+AI_WONT_RETURN void TokenizeError(const std::string& message, unsigned int line, unsigned int column)
+{
+    throw DeadlyImportError(Util::AddLineAndColumn("FBX-Tokenize",message,line,column));
+}
+
+
+// process a potential data token up to 'cur', adding it to 'output_tokens'.
+// ------------------------------------------------------------------------------------------------
+void ProcessDataToken( TokenList& output_tokens, const char*& start, const char*& end,
+                      unsigned int line,
+                      unsigned int column,
+                      TokenType type = TokenType_DATA,
+                      bool must_have_token = false)
+{
+    if (start && end) {
+        // sanity check:
+        // tokens should have no whitespace outside quoted text and [start,end] should
+        // properly delimit the valid range.
+        bool in_double_quotes = false;
+        for (const char* c = start; c != end + 1; ++c) {
+            if (*c == '\"') {
+                in_double_quotes = !in_double_quotes;
+            }
+
+            if (!in_double_quotes && IsSpaceOrNewLine(*c)) {
+                TokenizeError("unexpected whitespace in token", line, column);
+            }
+        }
+
+        if (in_double_quotes) {
+            TokenizeError("non-terminated double quotes", line, column);
+        }
+
+        output_tokens.push_back(new_Token(start,end + 1,type,line,column));
+    }
+    else if (must_have_token) {
+        TokenizeError("unexpected character, expected data token", line, column);
+    }
+
+    start = end = NULL;
+}
+
+}
+
+// ------------------------------------------------------------------------------------------------
+void Tokenize(TokenList& output_tokens, const char* input)
+{
+    ai_assert(input);
+
+    // line and column numbers numbers are one-based
+    unsigned int line = 1;
+    unsigned int column = 1;
+
+    bool comment = false;
+    bool in_double_quotes = false;
+    bool pending_data_token = false;
+
+    const char* token_begin = NULL, *token_end = NULL;
+    for (const char* cur = input;*cur;column += (*cur == '\t' ? ASSIMP_FBX_TAB_WIDTH : 1), ++cur) {
+        const char c = *cur;
+
+        if (IsLineEnd(c)) {
+            comment = false;
+
+            column = 0;
+            ++line;
+        }
+
+        if(comment) {
+            continue;
+        }
+
+        if(in_double_quotes) {
+            if (c == '\"') {
+                in_double_quotes = false;
+                token_end = cur;
+
+                ProcessDataToken(output_tokens,token_begin,token_end,line,column);
+                pending_data_token = false;
+            }
+            continue;
+        }
+
+        switch(c)
+        {
+        case '\"':
+            if (token_begin) {
+                TokenizeError("unexpected double-quote", line, column);
+            }
+            token_begin = cur;
+            in_double_quotes = true;
+            continue;
+
+        case ';':
+            ProcessDataToken(output_tokens,token_begin,token_end,line,column);
+            comment = true;
+            continue;
+
+        case '{':
+            ProcessDataToken(output_tokens,token_begin,token_end, line, column);
+            output_tokens.push_back(new_Token(cur,cur+1,TokenType_OPEN_BRACKET,line,column));
+            continue;
+
+        case '}':
+            ProcessDataToken(output_tokens,token_begin,token_end,line,column);
+            output_tokens.push_back(new_Token(cur,cur+1,TokenType_CLOSE_BRACKET,line,column));
+            continue;
+
+        case ',':
+            if (pending_data_token) {
+                ProcessDataToken(output_tokens,token_begin,token_end,line,column,TokenType_DATA,true);
+            }
+            output_tokens.push_back(new_Token(cur,cur+1,TokenType_COMMA,line,column));
+            continue;
+
+        case ':':
+            if (pending_data_token) {
+                ProcessDataToken(output_tokens,token_begin,token_end,line,column,TokenType_KEY,true);
+            }
+            else {
+                TokenizeError("unexpected colon", line, column);
+            }
+            continue;
+        }
+
+        if (IsSpaceOrNewLine(c)) {
+
+            if (token_begin) {
+                // peek ahead and check if the next token is a colon in which
+                // case this counts as KEY token.
+                TokenType type = TokenType_DATA;
+                for (const char* peek = cur;  *peek && IsSpaceOrNewLine(*peek); ++peek) {
+                    if (*peek == ':') {
+                        type = TokenType_KEY;
+                        cur = peek;
+                        break;
+                    }
+                }
+
+                ProcessDataToken(output_tokens,token_begin,token_end,line,column,type);
+            }
+
+            pending_data_token = false;
+        }
+        else {
+            token_end = cur;
+            if (!token_begin) {
+                token_begin = cur;
+            }
+
+            pending_data_token = true;
+        }
+    }
+}
+
+} // !FBX
+} // !Assimp
+
+#endif
diff --git a/thirdparty/assimp/code/FBX/FBXTokenizer.h b/thirdparty/assimp/code/FBX/FBXTokenizer.h
new file mode 100644
index 0000000000..afa588a470
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXTokenizer.h
@@ -0,0 +1,187 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXTokenizer.h
+ *  @brief FBX lexer
+ */
+#ifndef INCLUDED_AI_FBX_TOKENIZER_H
+#define INCLUDED_AI_FBX_TOKENIZER_H
+
+#include "FBXCompileConfig.h"
+#include <assimp/ai_assert.h>
+#include <vector>
+#include <string>
+
+namespace Assimp {
+namespace FBX {
+
+/** Rough classification for text FBX tokens used for constructing the
+ *  basic scope hierarchy. */
+enum TokenType
+{
+    // {
+    TokenType_OPEN_BRACKET = 0,
+
+    // }
+    TokenType_CLOSE_BRACKET,
+
+    // '"blablubb"', '2', '*14' - very general token class,
+    // further processing happens at a later stage.
+    TokenType_DATA,
+
+    //
+    TokenType_BINARY_DATA,
+
+    // ,
+    TokenType_COMMA,
+
+    // blubb:
+    TokenType_KEY
+};
+
+
+/** Represents a single token in a FBX file. Tokens are
+ *  classified by the #TokenType enumerated types.
+ *
+ *  Offers iterator protocol. Tokens are immutable. */
+class Token
+{
+private:
+    static const unsigned int BINARY_MARKER = static_cast<unsigned int>(-1);
+
+public:
+    /** construct a textual token */
+    Token(const char* sbegin, const char* send, TokenType type, unsigned int line, unsigned int column);
+
+    /** construct a binary token */
+    Token(const char* sbegin, const char* send, TokenType type, size_t offset);
+
+    ~Token();
+
+public:
+    std::string StringContents() const {
+        return std::string(begin(),end());
+    }
+
+    bool IsBinary() const {
+        return column == BINARY_MARKER;
+    }
+
+    const char* begin() const {
+        return sbegin;
+    }
+
+    const char* end() const {
+        return send;
+    }
+
+    TokenType Type() const {
+        return type;
+    }
+
+    size_t Offset() const {
+        ai_assert(IsBinary());
+        return offset;
+    }
+
+    unsigned int Line() const {
+        ai_assert(!IsBinary());
+        return static_cast<unsigned int>(line);
+    }
+
+    unsigned int Column() const {
+        ai_assert(!IsBinary());
+        return column;
+    }
+
+private:
+
+#ifdef DEBUG
+    // full string copy for the sole purpose that it nicely appears
+    // in msvc's debugger window.
+    const std::string contents;
+#endif
+
+
+    const char* const sbegin;
+    const char* const send;
+    const TokenType type;
+
+    union {
+        size_t line;
+        size_t offset;
+    };
+    const unsigned int column;
+};
+
+// XXX should use C++11's unique_ptr - but assimp's need to keep working with 03
+typedef const Token* TokenPtr;
+typedef std::vector< TokenPtr > TokenList;
+
+#define new_Token new Token
+
+
+/** Main FBX tokenizer function. Transform input buffer into a list of preprocessed tokens.
+ *
+ *  Skips over comments and generates line and column numbers.
+ *
+ * @param output_tokens Receives a list of all tokens in the input data.
+ * @param input_buffer Textual input buffer to be processed, 0-terminated.
+ * @throw DeadlyImportError if something goes wrong */
+void Tokenize(TokenList& output_tokens, const char* input);
+
+
+/** Tokenizer function for binary FBX files.
+ *
+ *  Emits a token list suitable for direct parsing.
+ *
+ * @param output_tokens Receives a list of all tokens in the input data.
+ * @param input_buffer Binary input buffer to be processed.
+ * @param length Length of input buffer, in bytes. There is no 0-terminal.
+ * @throw DeadlyImportError if something goes wrong */
+void TokenizeBinary(TokenList& output_tokens, const char* input, size_t length);
+
+
+} // ! FBX
+} // ! Assimp
+
+#endif // ! INCLUDED_AI_FBX_PARSER_H
diff --git a/thirdparty/assimp/code/FBX/FBXUtil.cpp b/thirdparty/assimp/code/FBX/FBXUtil.cpp
new file mode 100644
index 0000000000..c10e057c8c
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXUtil.cpp
@@ -0,0 +1,243 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXUtil.cpp
+ *  @brief Implementation of internal FBX utility functions
+ */
+
+#include "FBXUtil.h"
+#include "FBXTokenizer.h"
+
+#include <assimp/TinyFormatter.h>
+#include <string>
+#include <cstring>
+
+#ifndef ASSIMP_BUILD_NO_FBX_IMPORTER
+
+namespace Assimp {
+namespace FBX {
+namespace Util {
+
+// ------------------------------------------------------------------------------------------------
+const char* TokenTypeString(TokenType t)
+{
+    switch(t) {
+        case TokenType_OPEN_BRACKET:
+            return "TOK_OPEN_BRACKET";
+
+        case TokenType_CLOSE_BRACKET:
+            return "TOK_CLOSE_BRACKET";
+
+        case TokenType_DATA:
+            return "TOK_DATA";
+
+        case TokenType_COMMA:
+            return "TOK_COMMA";
+
+        case TokenType_KEY:
+            return "TOK_KEY";
+
+        case TokenType_BINARY_DATA:
+            return "TOK_BINARY_DATA";
+    }
+
+    ai_assert(false);
+    return "";
+}
+
+
+// ------------------------------------------------------------------------------------------------
+std::string AddOffset(const std::string& prefix, const std::string& text, size_t offset)
+{
+    return static_cast<std::string>( (Formatter::format() << prefix << " (offset 0x" << std::hex << offset << ") " << text) );
+}
+
+// ------------------------------------------------------------------------------------------------
+std::string AddLineAndColumn(const std::string& prefix, const std::string& text, unsigned int line, unsigned int column)
+{
+    return static_cast<std::string>( (Formatter::format() << prefix << " (line " << line << " <<  col " << column << ") " << text) );
+}
+
+// ------------------------------------------------------------------------------------------------
+std::string AddTokenText(const std::string& prefix, const std::string& text, const Token* tok)
+{
+    if(tok->IsBinary()) {
+        return static_cast<std::string>( (Formatter::format() << prefix <<
+            " (" << TokenTypeString(tok->Type()) <<
+            ", offset 0x" << std::hex << tok->Offset() << ") " <<
+            text) );
+    }
+
+    return static_cast<std::string>( (Formatter::format() << prefix <<
+        " (" << TokenTypeString(tok->Type()) <<
+        ", line " << tok->Line() <<
+        ", col " << tok->Column() << ") " <<
+        text) );
+}
+
+// Generated by this formula: T["ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"[i]] = i;
+static const uint8_t base64DecodeTable[128] = {
+    255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+    255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+    255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 62, 255, 255, 255, 63,
+    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 255, 255, 255, 255, 255, 255,
+    255, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
+    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 255, 255, 255, 255, 255,
+    255, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 255, 255, 255, 255, 255
+};
+
+uint8_t DecodeBase64(char ch)
+{
+    const auto idx = static_cast<uint8_t>(ch);
+    if (idx > 127)
+        return 255;
+    return base64DecodeTable[idx];
+}
+
+size_t ComputeDecodedSizeBase64(const char* in, size_t inLength)
+{
+    if (inLength < 2)
+    {
+        return 0;
+    }
+    const size_t equals = size_t(in[inLength - 1] == '=') + size_t(in[inLength - 2] == '=');
+    const size_t full_length = (inLength * 3) >> 2; // div by 4
+    if (full_length < equals)
+    {
+        return 0;
+    }
+    return full_length - equals;
+}
+
+size_t DecodeBase64(const char* in, size_t inLength, uint8_t* out, size_t maxOutLength)
+{
+    if (maxOutLength == 0 || inLength < 2) {
+        return 0;
+    }
+    const size_t realLength = inLength - size_t(in[inLength - 1] == '=') - size_t(in[inLength - 2] == '=');
+    size_t dst_offset = 0;
+    int val = 0, valb = -8;
+    for (size_t src_offset = 0; src_offset < realLength; ++src_offset)
+    {
+        const uint8_t table_value = Util::DecodeBase64(in[src_offset]);
+        if (table_value == 255)
+        {
+            return 0;
+        }
+        val = (val << 6) + table_value;
+        valb += 6;
+        if (valb >= 0)
+        {
+            out[dst_offset++] = static_cast<uint8_t>((val >> valb) & 0xFF);
+            valb -= 8;
+            val &= 0xFFF;
+        }
+    }
+    return dst_offset;
+}
+
+static const char to_base64_string[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+char EncodeBase64(char byte)
+{
+    return to_base64_string[(size_t)byte];
+}
+
+/** Encodes a block of 4 bytes to base64 encoding
+*
+*  @param bytes Bytes to encode.
+*  @param out_string String to write encoded values to.
+*  @param string_pos Position in out_string.*/
+void EncodeByteBlock(const char* bytes, std::string& out_string, size_t string_pos)
+{
+    char b0 = (bytes[0] & 0xFC) >> 2;
+    char b1 = (bytes[0] & 0x03) << 4 | ((bytes[1] & 0xF0) >> 4);
+    char b2 = (bytes[1] & 0x0F) << 2 | ((bytes[2] & 0xC0) >> 6);
+    char b3 = (bytes[2] & 0x3F);
+
+    out_string[string_pos + 0] = EncodeBase64(b0);
+    out_string[string_pos + 1] = EncodeBase64(b1);
+    out_string[string_pos + 2] = EncodeBase64(b2);
+    out_string[string_pos + 3] = EncodeBase64(b3);
+}
+
+std::string EncodeBase64(const char* data, size_t length)
+{
+    // calculate extra bytes needed to get a multiple of 3
+    size_t extraBytes = 3 - length % 3;
+
+    // number of base64 bytes
+    size_t encodedBytes = 4 * (length + extraBytes) / 3;
+
+    std::string encoded_string(encodedBytes, '=');
+
+    // read blocks of 3 bytes
+    for (size_t ib3 = 0; ib3 < length / 3; ib3++)
+    {
+        const size_t iByte = ib3 * 3;
+        const size_t iEncodedByte = ib3 * 4;
+        const char* currData = &data[iByte];
+
+        EncodeByteBlock(currData, encoded_string, iEncodedByte);
+    }
+
+    // if size of data is not a multiple of 3, also encode the final bytes (and add zeros where needed)
+    if (extraBytes > 0)
+    {
+        char finalBytes[4] = { 0,0,0,0 };
+        memcpy(&finalBytes[0], &data[length - length % 3], length % 3);
+
+        const size_t iEncodedByte = encodedBytes - 4;
+        EncodeByteBlock(&finalBytes[0], encoded_string, iEncodedByte);
+
+        // add '=' at the end
+        for (size_t i = 0; i < 4 * extraBytes / 3; i++)
+            encoded_string[encodedBytes - i - 1] = '=';
+    }
+    return encoded_string;
+}
+
+} // !Util
+} // !FBX
+} // !Assimp
+
+#endif
diff --git a/thirdparty/assimp/code/FBX/FBXUtil.h b/thirdparty/assimp/code/FBX/FBXUtil.h
new file mode 100644
index 0000000000..b634418858
--- /dev/null
+++ b/thirdparty/assimp/code/FBX/FBXUtil.h
@@ -0,0 +1,137 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2019, assimp team
+
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the
+following conditions are met:
+
+* Redistributions of source code must retain the above
+  copyright notice, this list of conditions and the
+  following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the
+  following disclaimer in the documentation and/or other
+  materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+  contributors may be used to endorse or promote products
+  derived from this software without specific prior
+  written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+----------------------------------------------------------------------
+*/
+
+/** @file  FBXUtil.h
+ *  @brief FBX utility functions for internal use
+ */
+#ifndef INCLUDED_AI_FBX_UTIL_H
+#define INCLUDED_AI_FBX_UTIL_H
+
+#include "FBXCompileConfig.h"
+#include "FBXTokenizer.h"
+#include <stdint.h>
+
+namespace Assimp {
+namespace FBX {
+
+
+namespace Util {
+
+
+/** helper for std::for_each to delete all heap-allocated items in a container */
+template<typename T>
+struct delete_fun
+{
+    void operator()(const volatile T* del) {
+        delete del;
+    }
+};
+
+/** Get a string representation for a #TokenType. */
+const char* TokenTypeString(TokenType t);
+
+
+
+/** Format log/error messages using a given offset in the source binary file
+ *
+ *  @param prefix Message prefix to be preprended to the location info.
+ *  @param text Message text
+ *  @param line Line index, 1-based
+ *  @param column Column index, 1-based
+ *  @return A string of the following format: {prefix} (offset 0x{offset}) {text}*/
+std::string AddOffset(const std::string& prefix, const std::string& text, size_t offset);
+
+
+/** Format log/error messages using a given line location in the source file.
+ *
+ *  @param prefix Message prefix to be preprended to the location info.
+ *  @param text Message text
+ *  @param line Line index, 1-based
+ *  @param column Column index, 1-based
+ *  @return A string of the following format: {prefix} (line {line}, col {column}) {text}*/
+std::string AddLineAndColumn(const std::string& prefix, const std::string& text, unsigned int line, unsigned int column);
+
+
+/** Format log/error messages using a given cursor token.
+ *
+ *  @param prefix Message prefix to be preprended to the location info.
+ *  @param text Message text
+ *  @param tok Token where parsing/processing stopped
+ *  @return A string of the following format: {prefix} ({token-type}, line {line}, col {column}) {text}*/
+std::string AddTokenText(const std::string& prefix, const std::string& text, const Token* tok);
+
+/** Decode a single Base64-encoded character.
+*
+*  @param ch Character to decode (from base64 to binary).
+*  @return decoded byte value*/
+uint8_t DecodeBase64(char ch);
+
+/** Compute decoded size of a Base64-encoded string
+*
+*  @param in Characters to decode.
+*  @param inLength Number of characters to decode.
+*  @return size of the decoded data (number of bytes)*/
+size_t ComputeDecodedSizeBase64(const char* in, size_t inLength);
+
+/** Decode a Base64-encoded string
+*
+*  @param in Characters to decode.
+*  @param inLength Number of characters to decode.
+*  @param out Pointer where we will store the decoded data.
+*  @param maxOutLength Size of output buffer.
+*  @return size of the decoded data (number of bytes)*/
+size_t DecodeBase64(const char* in, size_t inLength, uint8_t* out, size_t maxOutLength);
+
+char EncodeBase64(char byte);
+
+/** Encode bytes in base64-encoding
+*
+*  @param data Binary data to encode.
+*  @param inLength Number of bytes to encode.
+*  @return base64-encoded string*/
+std::string EncodeBase64(const char* data, size_t length);
+
+}
+}
+}
+
+#endif // ! INCLUDED_AI_FBX_UTIL_H