Port FBX module from commit 68013d23932688e57b489600f4517dd280edc464

Ports FBX module from 3.2 branch to 4.0

This is the only time the plugin will be updated from 3.2 and marks the final time we do this, from now on we will backport FBX to 3.2 with fixes.

Changelog:
- fixed crash importing files with buggy format (because of bad newlines in ASCII data, this is yet to be fixed fully)
- fixed const correctness with C++/C version change
- rewrote material handling to be simpler and better
- ports from 3.2 to 4.0 the fbx importer

4 files changed, 691 insertions, 0 deletions

diff --git a/modules/fbx/tools/import_utils.cpp b/modules/fbx/tools/import_utils.cpp
new file mode 100644
index 0000000000..5c9e433ab8
--- /dev/null
+++ b/modules/fbx/tools/import_utils.cpp
@@ -0,0 +1,151 @@
+/*************************************************************************/
+/*  import_utils.cpp                                                     */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "import_utils.h"
+
+Vector3 ImportUtils::deg2rad(const Vector3 &p_rotation) {
+	return p_rotation / 180.0 * Math_PI;
+}
+
+Vector3 ImportUtils::rad2deg(const Vector3 &p_rotation) {
+	return p_rotation / Math_PI * 180.0;
+}
+
+Basis ImportUtils::EulerToBasis(FBXDocParser::Model::RotOrder mode, const Vector3 &p_rotation) {
+	Basis ret;
+
+	// FBX is using intrinsic euler, we can convert intrinsic to extrinsic (the one used in godot
+	// by simply invert its order: https://www.cs.utexas.edu/~theshark/courses/cs354/lectures/cs354-14.pdf
+	switch (mode) {
+		case FBXDocParser::Model::RotOrder_EulerXYZ:
+			ret.set_euler_zyx(p_rotation);
+			break;
+
+		case FBXDocParser::Model::RotOrder_EulerXZY:
+			ret.set_euler_yzx(p_rotation);
+			break;
+
+		case FBXDocParser::Model::RotOrder_EulerYZX:
+			ret.set_euler_xzy(p_rotation);
+			break;
+
+		case FBXDocParser::Model::RotOrder_EulerYXZ:
+			ret.set_euler_zxy(p_rotation);
+			break;
+
+		case FBXDocParser::Model::RotOrder_EulerZXY:
+			ret.set_euler_yxz(p_rotation);
+			break;
+
+		case FBXDocParser::Model::RotOrder_EulerZYX:
+			ret.set_euler_xyz(p_rotation);
+			break;
+
+		case FBXDocParser::Model::RotOrder_SphericXYZ:
+			// TODO do this.
+			break;
+
+		default:
+			// If you land here, Please integrate all enums.
+			CRASH_NOW_MSG("This is not unreachable.");
+	}
+
+	return ret;
+}
+
+Quat ImportUtils::EulerToQuaternion(FBXDocParser::Model::RotOrder mode, const Vector3 &p_rotation) {
+	return ImportUtils::EulerToBasis(mode, p_rotation);
+}
+
+Vector3 ImportUtils::BasisToEuler(FBXDocParser::Model::RotOrder mode, const Basis &p_rotation) {
+	// FBX is using intrinsic euler, we can convert intrinsic to extrinsic (the one used in godot
+	// by simply invert its order: https://www.cs.utexas.edu/~theshark/courses/cs354/lectures/cs354-14.pdf
+	switch (mode) {
+		case FBXDocParser::Model::RotOrder_EulerXYZ:
+			return p_rotation.get_euler_zyx();
+
+		case FBXDocParser::Model::RotOrder_EulerXZY:
+			return p_rotation.get_euler_yzx();
+
+		case FBXDocParser::Model::RotOrder_EulerYZX:
+			return p_rotation.get_euler_xzy();
+
+		case FBXDocParser::Model::RotOrder_EulerYXZ:
+			return p_rotation.get_euler_zxy();
+
+		case FBXDocParser::Model::RotOrder_EulerZXY:
+			return p_rotation.get_euler_yxz();
+
+		case FBXDocParser::Model::RotOrder_EulerZYX:
+			return p_rotation.get_euler_xyz();
+
+		case FBXDocParser::Model::RotOrder_SphericXYZ:
+			// TODO
+			return Vector3();
+
+		default:
+			// If you land here, Please integrate all enums.
+			CRASH_NOW_MSG("This is not unreachable.");
+			return Vector3();
+	}
+}
+
+Vector3 ImportUtils::QuaternionToEuler(FBXDocParser::Model::RotOrder mode, const Quat &p_rotation) {
+	return BasisToEuler(mode, p_rotation);
+}
+
+Transform get_unscaled_transform(const Transform &p_initial, real_t p_scale) {
+	Transform unscaled = Transform(p_initial.basis, p_initial.origin * p_scale);
+	ERR_FAIL_COND_V_MSG(unscaled.basis.determinant() == 0, Transform(), "det is zero unscaled?");
+	return unscaled;
+}
+
+Vector3 get_poly_normal(const std::vector<Vector3> &p_vertices) {
+	ERR_FAIL_COND_V_MSG(p_vertices.size() < 3, Vector3(0, 0, 0), "At least 3 vertices are necesary");
+	// Using long double to make sure that normal is computed for even really tiny objects.
+	typedef long double ldouble;
+	ldouble x = 0.0;
+	ldouble y = 0.0;
+	ldouble z = 0.0;
+	for (size_t i = 0; i < p_vertices.size(); i += 1) {
+		const Vector3 current = p_vertices[i];
+		const Vector3 next = p_vertices[(i + 1) % p_vertices.size()];
+		x += (ldouble(current.y) - ldouble(next.y)) * (ldouble(current.z) + ldouble(next.z));
+		y += (ldouble(current.z) - ldouble(next.z)) * (ldouble(current.x) + ldouble(next.x));
+		z += (ldouble(current.x) - ldouble(next.x)) * (ldouble(current.y) + ldouble(next.y));
+	}
+	const ldouble l2 = x * x + y * y + z * z;
+	if (l2 == 0.0) {
+		return (p_vertices[0] - p_vertices[1]).normalized().cross((p_vertices[0] - p_vertices[2]).normalized()).normalized();
+	} else {
+		const double l = Math::sqrt(double(l2));
+		return Vector3(x / l, y / l, z / l);
+	}
+}
diff --git a/modules/fbx/tools/import_utils.h b/modules/fbx/tools/import_utils.h
new file mode 100644
index 0000000000..98a0cef908
--- /dev/null
+++ b/modules/fbx/tools/import_utils.h
@@ -0,0 +1,400 @@
+/*************************************************************************/
+/*  import_utils.h                                                       */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef IMPORT_UTILS_FBX_IMPORTER_H
+#define IMPORT_UTILS_FBX_IMPORTER_H
+
+#include "core/io/image_loader.h"
+
+#include "data/import_state.h"
+#include "fbx_parser/FBXDocument.h"
+
+#include <string>
+
+#define CONVERT_FBX_TIME(time) static_cast<double>(time) / 46186158000LL
+
+/**
+ * Import Utils
+ * Conversion tools / glue code to convert from FBX to Godot
+*/
+class ImportUtils {
+public:
+	///	Convert a vector from degrees to radians.
+	static Vector3 deg2rad(const Vector3 &p_rotation);
+
+	///	Convert a vector from radians to degrees.
+	static Vector3 rad2deg(const Vector3 &p_rotation);
+
+	/// Converts rotation order vector (in rad) to quaternion.
+	static Basis EulerToBasis(FBXDocParser::Model::RotOrder mode, const Vector3 &p_rotation);
+
+	/// Converts rotation order vector (in rad) to quaternion.
+	static Quat EulerToQuaternion(FBXDocParser::Model::RotOrder mode, const Vector3 &p_rotation);
+
+	/// Converts basis into rotation order vector (in rad).
+	static Vector3 BasisToEuler(FBXDocParser::Model::RotOrder mode, const Basis &p_rotation);
+
+	/// Converts quaternion into rotation order vector (in rad).
+	static Vector3 QuaternionToEuler(FBXDocParser::Model::RotOrder mode, const Quat &p_rotation);
+
+	static void debug_xform(String name, const Transform &t) {
+		print_verbose(name + " " + t.origin + " rotation: " + (t.basis.get_euler() * (180 / Math_PI)));
+	}
+
+	static String FBXNodeToName(const std::string &name) {
+		// strip Model:: prefix, avoiding ambiguities (i.e. don't strip if
+		// this causes ambiguities, well possible between empty identifiers,
+		// such as "Model::" and ""). Make sure the behaviour is consistent
+		// across multiple calls to FixNodeName().
+
+		// We must remove this from the name
+		// Some bones have this
+		// SubDeformer::
+		// Meshes, Joints have this, some other IK elements too.
+		// Model::
+
+		String node_name = String(name.c_str());
+
+		if (node_name.substr(0, 7) == "Model::") {
+			node_name = node_name.substr(7, node_name.length() - 7);
+			return node_name.replace(":", "");
+		}
+
+		if (node_name.substr(0, 13) == "SubDeformer::") {
+			node_name = node_name.substr(13, node_name.length() - 13);
+			return node_name.replace(":", "");
+		}
+
+		if (node_name.substr(0, 11) == "AnimStack::") {
+			node_name = node_name.substr(11, node_name.length() - 11);
+			return node_name.replace(":", "");
+		}
+
+		if (node_name.substr(0, 15) == "AnimCurveNode::") {
+			node_name = node_name.substr(15, node_name.length() - 15);
+			return node_name.replace(":", "");
+		}
+
+		if (node_name.substr(0, 11) == "AnimCurve::") {
+			node_name = node_name.substr(11, node_name.length() - 11);
+			return node_name.replace(":", "");
+		}
+
+		if (node_name.substr(0, 10) == "Geometry::") {
+			node_name = node_name.substr(10, node_name.length() - 10);
+			return node_name.replace(":", "");
+		}
+
+		if (node_name.substr(0, 10) == "Material::") {
+			node_name = node_name.substr(10, node_name.length() - 10);
+			return node_name.replace(":", "");
+		}
+
+		if (node_name.substr(0, 9) == "Texture::") {
+			node_name = node_name.substr(9, node_name.length() - 9);
+			return node_name.replace(":", "");
+		}
+
+		return node_name.replace(":", "");
+	}
+
+	static std::string FBXAnimMeshName(const std::string &name) {
+		if (name.length()) {
+			size_t indexOf = name.find_first_of("::");
+			if (indexOf != std::string::npos && indexOf < name.size() - 2) {
+				return name.substr(indexOf + 2);
+			}
+		}
+		return name.length() ? name : "AnimMesh";
+	}
+
+	static Vector3 safe_import_vector3(const Vector3 &p_vec) {
+		Vector3 vector = p_vec;
+		if (Math::is_equal_approx(0, vector.x)) {
+			vector.x = 0;
+		}
+
+		if (Math::is_equal_approx(0, vector.y)) {
+			vector.y = 0;
+		}
+
+		if (Math::is_equal_approx(0, vector.z)) {
+			vector.z = 0;
+		}
+		return vector;
+	}
+
+	static void debug_xform(String name, const Basis &t) {
+		//print_verbose(name + " rotation: " + (t.get_euler() * (180 / Math_PI)));
+	}
+
+	static Vector3 FixAxisConversions(Vector3 input) {
+		return Vector3(input.x, input.y, input.z);
+	}
+
+	static void AlignMeshAxes(std::vector<Vector3> &vertex_data) {
+		for (size_t x = 0; x < vertex_data.size(); x++) {
+			vertex_data[x] = FixAxisConversions(vertex_data[x]);
+		}
+	}
+
+	struct AssetImportFbx {
+		enum ETimeMode {
+			TIME_MODE_DEFAULT = 0,
+			TIME_MODE_120 = 1,
+			TIME_MODE_100 = 2,
+			TIME_MODE_60 = 3,
+			TIME_MODE_50 = 4,
+			TIME_MODE_48 = 5,
+			TIME_MODE_30 = 6,
+			TIME_MODE_30_DROP = 7,
+			TIME_MODE_NTSC_DROP_FRAME = 8,
+			TIME_MODE_NTSC_FULL_FRAME = 9,
+			TIME_MODE_PAL = 10,
+			TIME_MODE_CINEMA = 11,
+			TIME_MODE_1000 = 12,
+			TIME_MODE_CINEMA_ND = 13,
+			TIME_MODE_CUSTOM = 14,
+			TIME_MODE_TIME_MODE_COUNT = 15
+		};
+		enum UpAxis {
+			UP_VECTOR_AXIS_X = 1,
+			UP_VECTOR_AXIS_Y = 2,
+			UP_VECTOR_AXIS_Z = 3
+		};
+		enum FrontAxis {
+			FRONT_PARITY_EVEN = 1,
+			FRONT_PARITY_ODD = 2,
+		};
+
+		enum CoordAxis {
+			COORD_RIGHT = 0,
+			COORD_LEFT = 1
+		};
+	};
+
+	/** Get fbx fps for time mode meta data
+     */
+	static float get_fbx_fps(int32_t time_mode) {
+		switch (time_mode) {
+			case AssetImportFbx::TIME_MODE_DEFAULT:
+				return 24;
+			case AssetImportFbx::TIME_MODE_120:
+				return 120;
+			case AssetImportFbx::TIME_MODE_100:
+				return 100;
+			case AssetImportFbx::TIME_MODE_60:
+				return 60;
+			case AssetImportFbx::TIME_MODE_50:
+				return 50;
+			case AssetImportFbx::TIME_MODE_48:
+				return 48;
+			case AssetImportFbx::TIME_MODE_30:
+				return 30;
+			case AssetImportFbx::TIME_MODE_30_DROP:
+				return 30;
+			case AssetImportFbx::TIME_MODE_NTSC_DROP_FRAME:
+				return 29.9700262f;
+			case AssetImportFbx::TIME_MODE_NTSC_FULL_FRAME:
+				return 29.9700262f;
+			case AssetImportFbx::TIME_MODE_PAL:
+				return 25;
+			case AssetImportFbx::TIME_MODE_CINEMA:
+				return 24;
+			case AssetImportFbx::TIME_MODE_1000:
+				return 1000;
+			case AssetImportFbx::TIME_MODE_CINEMA_ND:
+				return 23.976f;
+			case AssetImportFbx::TIME_MODE_CUSTOM:
+				return -1;
+		}
+		return 0;
+	}
+
+	static float get_fbx_fps(const FBXDocParser::FileGlobalSettings *FBXSettings) {
+		int time_mode = FBXSettings->TimeMode();
+
+		// get the animation FPS
+		float frames_per_second = get_fbx_fps(time_mode);
+
+		// handle animation custom FPS time.
+		if (time_mode == ImportUtils::AssetImportFbx::TIME_MODE_CUSTOM) {
+			print_verbose("FBX Animation has custom FPS setting");
+			frames_per_second = FBXSettings->CustomFrameRate();
+
+			// not our problem this is the modeller, we can print as an error so they can fix the source.
+			if (frames_per_second == 0) {
+				print_error("Custom animation time in file is set to 0 value, animation won't play, please edit your file to correct the FPS value");
+			}
+		}
+		return frames_per_second;
+	}
+
+	/**
+	  * Find hardcoded textures from assimp which could be in many different directories
+	  */
+
+	/**
+	  * set_texture_mapping_mode
+	  * Helper to check the mapping mode of the texture (repeat, clamp and mirror)
+	  */
+	// static void set_texture_mapping_mode(aiTextureMapMode *map_mode, Ref<ImageTexture> texture) {
+	// 	ERR_FAIL_COND(texture.is_null());
+	// 	ERR_FAIL_COND(map_mode == NULL);
+	// 	aiTextureMapMode tex_mode = map_mode[0];
+
+	// 	int32_t flags = Texture::FLAGS_DEFAULT;
+	// 	if (tex_mode == aiTextureMapMode_Wrap) {
+	// 		//Default
+	// 	} else if (tex_mode == aiTextureMapMode_Clamp) {
+	// 		flags = flags & ~Texture::FLAG_REPEAT;
+	// 	} else if (tex_mode == aiTextureMapMode_Mirror) {
+	// 		flags = flags | Texture::FLAG_MIRRORED_REPEAT;
+	// 	}
+	// 	texture->set_flags(flags);
+	// }
+
+	/**
+	  * Load or load from cache image :)
+	  * We need to upgrade this in the later version :) should not be hard
+	  */
+	//static Ref<Image> load_image(ImportState &state, const aiScene *p_scene, String p_path){
+	// Map<String, Ref<Image> >::Element *match = state.path_to_image_cache.find(p_path);
+
+	// // if our cache contains this image then don't bother
+	// if (match) {
+	// 	return match->get();
+	// }
+
+	// Vector<String> split_path = p_path.get_basename().split("*");
+	// if (split_path.size() == 2) {
+	// 	size_t texture_idx = split_path[1].to_int();
+	// 	ERR_FAIL_COND_V(texture_idx >= p_scene->mNumTextures, Ref<Image>());
+	// 	aiTexture *tex = p_scene->mTextures[texture_idx];
+	// 	String filename = AssimpUtils::get_raw_string_from_assimp(tex->mFilename);
+	// 	filename = filename.get_file();
+	// 	print_verbose("Open Asset Import: Loading embedded texture " + filename);
+	// 	if (tex->mHeight == 0) {
+	// 		if (tex->CheckFormat("png")) {
+	// 			Ref<Image> img = Image::_png_mem_loader_func((uint8_t *)tex->pcData, tex->mWidth);
+	// 			ERR_FAIL_COND_V(img.is_null(), Ref<Image>());
+	// 			state.path_to_image_cache.insert(p_path, img);
+	// 			return img;
+	// 		} else if (tex->CheckFormat("jpg")) {
+	// 			Ref<Image> img = Image::_jpg_mem_loader_func((uint8_t *)tex->pcData, tex->mWidth);
+	// 			ERR_FAIL_COND_V(img.is_null(), Ref<Image>());
+	// 			state.path_to_image_cache.insert(p_path, img);
+	// 			return img;
+	// 		} else if (tex->CheckFormat("dds")) {
+	// 			ERR_FAIL_COND_V_MSG(true, Ref<Image>(), "Open Asset Import: Embedded dds not implemented");
+	// 		}
+	// 	} else {
+	// 		Ref<Image> img;
+	// 		img.instance();
+	// 		PoolByteArray arr;
+	// 		uint32_t size = tex->mWidth * tex->mHeight;
+	// 		arr.resize(size);
+	// 		memcpy(arr.write().ptr(), tex->pcData, size);
+	// 		ERR_FAIL_COND_V(arr.size() % 4 != 0, Ref<Image>());
+	// 		//ARGB8888 to RGBA8888
+	// 		for (int32_t i = 0; i < arr.size() / 4; i++) {
+	// 			arr.write().ptr()[(4 * i) + 3] = arr[(4 * i) + 0];
+	// 			arr.write().ptr()[(4 * i) + 0] = arr[(4 * i) + 1];
+	// 			arr.write().ptr()[(4 * i) + 1] = arr[(4 * i) + 2];
+	// 			arr.write().ptr()[(4 * i) + 2] = arr[(4 * i) + 3];
+	// 		}
+	// 		img->create(tex->mWidth, tex->mHeight, true, Image::FORMAT_RGBA8, arr);
+	// 		ERR_FAIL_COND_V(img.is_null(), Ref<Image>());
+	// 		state.path_to_image_cache.insert(p_path, img);
+	// 		return img;
+	// 	}
+	// 	return Ref<Image>();
+	// } else {
+	// 	Ref<Texture> texture = ResourceLoader::load(p_path);
+	// 	ERR_FAIL_COND_V(texture.is_null(), Ref<Image>());
+	// 	Ref<Image> image = texture->get_data();
+	// 	ERR_FAIL_COND_V(image.is_null(), Ref<Image>());
+	// 	state.path_to_image_cache.insert(p_path, image);
+	// 	return image;
+	// }
+
+	// return Ref<Image>();
+	//}
+
+	// /* create texture from assimp data, if found in path */
+	// static bool CreateAssimpTexture(
+	// 		AssimpImporter::ImportState &state,
+	// 		aiString texture_path,
+	// 		String &filename,
+	// 		String &path,
+	// 		AssimpImageData &image_state) {
+	// 	filename = get_raw_string_from_assimp(texture_path);
+	// 	path = state.path.get_base_dir().plus_file(filename.replace("\\", "/"));
+	// 	bool found = false;
+	// 	find_texture_path(state.path, path, found);
+	// 	if (found) {
+	// 		image_state.raw_image = AssimpUtils::load_image(state, state.assimp_scene, path);
+	// 		if (image_state.raw_image.is_valid()) {
+	// 			image_state.texture.instance();
+	// 			image_state.texture->create_from_image(image_state.raw_image);
+	// 			image_state.texture->set_storage(ImageTexture::STORAGE_COMPRESS_LOSSY);
+	// 			return true;
+	// 		}
+	// 	}
+
+	// 	return false;
+	// }
+	// /** GetAssimpTexture
+	//   * Designed to retrieve textures for you
+	//   */
+	// static bool GetAssimpTexture(
+	// 		AssimpImporter::ImportState &state,
+	// 		aiMaterial *ai_material,
+	// 		aiTextureType texture_type,
+	// 		String &filename,
+	// 		String &path,
+	// 		AssimpImageData &image_state) {
+	// 	aiString ai_filename = aiString();
+	// 	if (AI_SUCCESS == ai_material->GetTexture(texture_type, 0, &ai_filename, NULL, NULL, NULL, NULL, image_state.map_mode)) {
+	// 		return CreateAssimpTexture(state, ai_filename, filename, path, image_state);
+	// 	}
+
+	// 	return false;
+	// }
+};
+
+// Apply the transforms so the basis will have scale 1.
+Transform get_unscaled_transform(const Transform &p_initial, real_t p_scale);
+
+/// Uses the Newell's method to compute any polygon normal.
+/// The polygon must be at least size of 3 or bigger.
+Vector3 get_poly_normal(const std::vector<Vector3> &p_vertices);
+
+#endif // IMPORT_UTILS_FBX_IMPORTER_H
diff --git a/modules/fbx/tools/validation_tools.cpp b/modules/fbx/tools/validation_tools.cpp
new file mode 100644
index 0000000000..0c4d7abe8d
--- /dev/null
+++ b/modules/fbx/tools/validation_tools.cpp
@@ -0,0 +1,48 @@
+/*************************************************************************/
+/*  validation_tools.cpp                                                 */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "validation_tools.h"
+
+#ifdef TOOLS_ENABLED
+
+#include "core/string/print_string.h"
+#include "core/string/ustring.h"
+
+ValidationTracker::Entries *ValidationTracker::entries_singleton = memnew(ValidationTracker::Entries);
+
+// for printing our CSV to dump validation problems of files
+// later we can make some agnostic tooling for this but this is fine for the time being.
+void ValidationTracker::Entries::add_validation_error(String asset_path, String message) {
+	print_error(message);
+	// note: implementation is static
+	validation_entries[asset_path].push_back(message);
+}
+
+#endif // TOOLS_ENABLED
diff --git a/modules/fbx/tools/validation_tools.h b/modules/fbx/tools/validation_tools.h
new file mode 100644
index 0000000000..649842a1cb
--- /dev/null
+++ b/modules/fbx/tools/validation_tools.h
@@ -0,0 +1,92 @@
+/*************************************************************************/
+/*  validation_tools.h                                                   */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef FBX_VALIDATION_TOOLS_H
+#define FBX_VALIDATION_TOOLS_H
+
+#ifdef TOOLS_ENABLED
+
+#include "core/io/json.h"
+#include "core/os/file_access.h"
+#include "core/string/ustring.h"
+#include "core/templates/local_vector.h"
+#include "core/templates/map.h"
+
+class ValidationTracker {
+protected:
+	struct Entries {
+		Map<String, LocalVector<String>> validation_entries = Map<String, LocalVector<String>>();
+
+		// for printing our CSV to dump validation problems of files
+		// later we can make some agnostic tooling for this but this is fine for the time being.
+		void add_validation_error(String asset_path, String message);
+		void print_to_csv() {
+			print_verbose("Exporting assset validation log please wait");
+			String massive_log_file;
+
+			String csv_header = "file_path, error message, extra data\n";
+			massive_log_file += csv_header;
+
+			for (Map<String, LocalVector<String>>::Element *element = validation_entries.front(); element; element = element->next()) {
+				for (unsigned int x = 0; x < element->value().size(); x++) {
+					const String &line_entry = element->key() + ", " + element->value()[x].c_escape() + "\n";
+					massive_log_file += line_entry;
+				}
+			}
+
+			String path = "asset_validation_errors.csv";
+			Error err;
+			FileAccess *file = FileAccess::open(path, FileAccess::WRITE, &err);
+			if (!file || err) {
+				if (file)
+					memdelete(file);
+				print_error("ValidationTracker Error - failed to create file - path: %s\n" + path);
+				return;
+			}
+
+			file->store_string(massive_log_file);
+			if (file->get_error() != OK && file->get_error() != ERR_FILE_EOF) {
+				print_error("ValidationTracker Error - failed to write to file - path: %s\n" + path);
+			}
+			file->close();
+			memdelete(file);
+		}
+	};
+	// asset path, error messages
+	static Entries *entries_singleton;
+
+public:
+	static Entries *get_singleton() {
+		return entries_singleton;
+	}
+};
+
+#endif // TOOLS_ENABLED
+#endif // FBX_VALIDATION_TOOLS_H