Merge pull request #44599 from RevoluPowered/remove_assimp_fbx

[fbx] remove old assimp plugin - pending fbx upgrade

1 files changed, 0 insertions, 2556 deletions

diff --git a/thirdparty/assimp/code/FBX/FBXExporter.cpp b/thirdparty/assimp/code/FBX/FBXExporter.cpp
deleted file mode 100644
index 9316dc4f02..0000000000
--- a/thirdparty/assimp/code/FBX/FBXExporter.cpp
+++ /dev/null
@@ -1,2556 +0,0 @@
-/*
-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>
-#include <numeric>
-
-// 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);
-
-    bool bJoinIdenticalVertices = mProperties->GetPropertyBool("bJoinIdenticalVertices", true);
-    std::vector<std::vector<int32_t>> vVertexIndice;//save vertex_indices as it is needed later
-
-    // 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;
-        if(bJoinIdenticalVertices){
-            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));
-                }
-            }
-        }
-        else { // do not join vertex, respect the export flag
-            vertex_indices.resize(m->mNumVertices);
-            std::iota(vertex_indices.begin(), vertex_indices.end(), 0);
-            for(unsigned int v = 0; v < m->mNumVertices; ++ v) {
-                aiVector3D vtx = m->mVertices[v];
-                flattened_vertices.push_back(vtx.x);
-                flattened_vertices.push_back(vtx.y);
-                flattened_vertices.push_back(vtx.z);
-            }
-        }
-        vVertexIndice.push_back(vertex_indices);
-
-        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);
-        }
-
-        // colors, if any
-        // TODO only one color channel currently
-        const int32_t colorChannelIndex = 0;
-        if (m->HasVertexColors(colorChannelIndex)) {
-            FBX::Node vertexcolors("LayerElementColor", int32_t(colorChannelIndex));
-            vertexcolors.Begin(outstream, binary, indent);
-            vertexcolors.DumpProperties(outstream, binary, indent);
-            vertexcolors.EndProperties(outstream, binary, indent);
-            vertexcolors.BeginChildren(outstream, binary, indent);
-            indent = 3;
-            FBX::Node::WritePropertyNode(
-                "Version", int32_t(101), outstream, binary, indent
-            );
-            char layerName[8];
-            sprintf(layerName, "COLOR_%d", colorChannelIndex);
-            FBX::Node::WritePropertyNode(
-                "Name", (const char*)layerName, outstream, binary, indent
-            );
-            FBX::Node::WritePropertyNode(
-                "MappingInformationType", "ByPolygonVertex",
-                outstream, binary, indent
-            );
-            FBX::Node::WritePropertyNode(
-                "ReferenceInformationType", "Direct",
-                outstream, binary, indent
-            );
-            std::vector<double> color_data;
-            color_data.reserve(4 * 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 aiColor4D &c = m->mColors[colorChannelIndex][f.mIndices[pvi]];
-                    color_data.push_back(c.r);
-                    color_data.push_back(c.g);
-                    color_data.push_back(c.b);
-                    color_data.push_back(c.a);
-                }
-            }
-            FBX::Node::WritePropertyNode(
-                "Colors", color_data, outstream, binary, indent
-            );
-            indent = 2;
-            vertexcolors.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);
-        // TODO only 1 color channel currently
-        le = FBX::Node("LayerElement");
-        le.AddChild("Type", "LayerElementColor");
-        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(lr));
-            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; }
-                }
-                
-                // 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]);
-
-        //computed before
-        std::vector<int32_t>& vertex_indices = vVertexIndice[mi];
-
-        // 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;
-
-            sdnode.AddChild("Transform", tr);
-
-
-            sdnode.AddChild("TransformLink", bone_xform);
-            // 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,
-    const 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