assimp/code/FBXConverter.cpp

/*
Open Asset Import Library (assimp)
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All rights reserved.

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  following disclaimer.

* Redistributions in binary form must reproduce the above
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*/

/** @file  FBXConverter.cpp
 *  @brief Implementation of the FBX DOM -> aiScene converter
 */
#include "AssimpPCH.h"

#ifndef ASSIMP_BUILD_NO_FBX_IMPORTER

#include <boost/tuple/tuple.hpp>

#include "FBXParser.h"
#include "FBXConverter.h"
#include "FBXDocument.h"
#include "FBXUtil.h"
#include "FBXProperties.h"
#include "FBXImporter.h"

namespace Assimp {
namespace FBX {

	using namespace Util;


#define MAGIC_NODE_TAG "_$AssimpFbx$"

	// XXX vc9's debugger won't step into anonymous namespaces
//namespace {

/** Dummy class to encapsulate the conversion process */
class Converter
{

public:

	Converter(aiScene* out, const Document& doc)
		: out(out) 
		, doc(doc)
	{
		// animations need to be converted first since this will
		// populate the node_anim_chain_bits map, which is needed
		// to determine which nodes need to be generated.
		ConvertAnimations();
		ConvertRootNode();

		if(doc.Settings().readAllMaterials) {
			// unfortunately this means we have to evaluate all objects
			BOOST_FOREACH(const ObjectMap::value_type& v,doc.Objects()) {

				const Object* ob = v.second->Get();
				if(!ob) {
					continue;
				}

				const Material* mat = dynamic_cast<const Material*>(ob);
				if(mat) {

					if (materials_converted.find(mat) == materials_converted.end()) {
						ConvertMaterial(*mat);
					}
				}
			}
		}

		TransferDataToScene();
	}


	~Converter()
	{
		std::for_each(meshes.begin(),meshes.end(),Util::delete_fun<aiMesh>());
		std::for_each(materials.begin(),materials.end(),Util::delete_fun<aiMaterial>());
		std::for_each(animations.begin(),animations.end(),Util::delete_fun<aiAnimation>());
	}


private:

	// ------------------------------------------------------------------------------------------------
	// find scene root and trigger recursive scene conversion
	void ConvertRootNode() 
	{
		out->mRootNode = new aiNode();
		out->mRootNode->mName.Set("RootNode");

		// root has ID 0
		ConvertNodes(0L, *out->mRootNode);
	}


	// ------------------------------------------------------------------------------------------------
	// collect and assign child nodes
	void ConvertNodes(uint64_t id, aiNode& parent)
	{
		const std::vector<const Connection*>& conns = doc.GetConnectionsByDestinationSequenced(id, "Model");

		std::vector<aiNode*> nodes;
		nodes.reserve(conns.size());

		std::vector<aiNode*> nodes_chain;

		try {
			BOOST_FOREACH(const Connection* con, conns) {

				// ignore object-property links
				if(con->PropertyName().length()) {
					continue;
				}

				const Object* const object = con->SourceObject();
				if(!object) {
					FBXImporter::LogWarn("failed to convert source object for Model link");
					continue;
				}

				const Model* const model = dynamic_cast<const Model*>(object);

				if(model) {
					nodes_chain.clear();
					GenerateTransformationNodeChain(*model,nodes_chain);

					ai_assert(nodes_chain.size());

					// link all nodes in a row
					aiNode* last_parent = &parent;
					BOOST_FOREACH(aiNode* prenode, nodes_chain) {
						ai_assert(prenode);

						if(last_parent != &parent) {
							last_parent->mNumChildren = 1;
							last_parent->mChildren = new aiNode*[1];
							last_parent->mChildren[0] = prenode;
						}

						prenode->mParent = last_parent;
						last_parent = prenode;
					}

					// attach geometry
					ConvertModel(*model, *nodes_chain.back());

					// attach sub-nodes
					ConvertNodes(model->ID(), *nodes_chain.back());

					nodes.push_back(nodes_chain.front());	
					nodes_chain.clear();
				}
			}

			if(nodes.size()) {
				parent.mChildren = new aiNode*[nodes.size()]();
				parent.mNumChildren = static_cast<unsigned int>(nodes.size());

				std::swap_ranges(nodes.begin(),nodes.end(),parent.mChildren);
			}
		} 
		catch(std::exception&)	{
			Util::delete_fun<aiNode> deleter;
			std::for_each(nodes.begin(),nodes.end(),deleter);
			std::for_each(nodes_chain.begin(),nodes_chain.end(),deleter);
		}
	}

	/** the different parts that make up the final local transformation of a fbx node */
	enum TransformationComp
	{
		TransformationComp_Translation = 0,
		TransformationComp_RotationOffset,
		TransformationComp_RotationPivot,
		TransformationComp_PreRotation,
		TransformationComp_Rotation,
		TransformationComp_PostRotation,
		TransformationComp_RotationPivotInverse,
		TransformationComp_ScalingOffset,
		TransformationComp_ScalingPivot,
		TransformationComp_Scaling,
		TransformationComp_ScalingPivotInverse,

		TransformationComp_MAXIMUM
	};


	// ------------------------------------------------------------------------------------------------
	// this returns unified names usable within assimp identifiers (i.e. no space characters -
	// while these would be allowed, they are a potential trouble spot so better not use them).
	const char* NameTransformationComp(TransformationComp comp)
	{
		switch(comp)
		{
		case TransformationComp_Translation:
			return "Translation";
		case TransformationComp_RotationOffset:
			return "RotationOffset";
		case TransformationComp_RotationPivot:
			return "RotationPivot";
		case TransformationComp_PreRotation:
			return "PreRotation";
		case TransformationComp_Rotation:
			return "Rotation";
		case TransformationComp_PostRotation:
			return "PostRotation";
		case TransformationComp_RotationPivotInverse:
			return "RotationPivotInverse";
		case TransformationComp_ScalingOffset:
			return "ScalingOffset";
		case TransformationComp_ScalingPivot:
			return "ScalingPivot";
		case TransformationComp_Scaling:
			return "Scaling";
		case TransformationComp_ScalingPivotInverse:
			return "ScalingPivotInverse";
		}

		ai_assert(false);
		return NULL;
	}


	// ------------------------------------------------------------------------------------------------
	// note: this returns the REAL fbx property names
	const char* NameTransformationCompProperty(TransformationComp comp)
	{
		switch(comp)
		{
		case TransformationComp_Translation:
			return "Lcl Translation";
		case TransformationComp_RotationOffset:
			return "RotationOffset";
		case TransformationComp_RotationPivot:
			return "RotationPivot";
		case TransformationComp_PreRotation:
			return "PreRotation";
		case TransformationComp_Rotation:
			return "Lcl Rotation";
		case TransformationComp_PostRotation:
			return "PostRotation";
		case TransformationComp_RotationPivotInverse:
			return "RotationPivotInverse";
		case TransformationComp_ScalingOffset:
			return "ScalingOffset";
		case TransformationComp_ScalingPivot:
			return "ScalingPivot";
		case TransformationComp_Scaling:
			return "Lcl Scaling";
		case TransformationComp_ScalingPivotInverse:
			return "ScalingPivotInverse";
		}

		ai_assert(false);
		return NULL;
	}


	// ------------------------------------------------------------------------------------------------
	aiVector3D TransformationCompDefaultValue(TransformationComp comp)
	{
		// XXX a neat way to solve the never-ending special cases for scaling 
		// would be to do everything in log space!
		return comp == TransformationComp_Scaling ? aiVector3D(1.f,1.f,1.f) : aiVector3D();
	}


	enum RotationMode
	{
		RotationMode_Euler_XYZ
	};


	// ------------------------------------------------------------------------------------------------
	void GetRotationMatrix(RotationMode mode, const aiVector3D& rotation, aiMatrix4x4& out)
	{
		const float angle_epsilon = 1e-6f;
		aiMatrix4x4 temp;

		out = aiMatrix4x4();

		switch(mode)
		{
		case RotationMode_Euler_XYZ:

			if(fabs(rotation.x) > angle_epsilon) {
				out *= aiMatrix4x4::RotationX(rotation.x,temp);
			}
			if(fabs(rotation.y) > angle_epsilon) {
				out *= aiMatrix4x4::RotationY(rotation.y,temp);
			}
			if(fabs(rotation.z) > angle_epsilon) {
				out *= aiMatrix4x4::RotationZ(rotation.z,temp);
			}

			return;
		}

		ai_assert(false);
	}


	// ------------------------------------------------------------------------------------------------
	/** checks if a node has more than just scaling, rotation and translation components */
	bool NeedsComplexTransformationChain(const Model& model)
	{
		return true;

		const PropertyTable& props = model.Props();
		bool ok;

		const float zero_epsilon = 1e-6f;
		for (size_t i = 0; i < TransformationComp_MAXIMUM; ++i) {
			const TransformationComp comp = static_cast<TransformationComp>(i);

			if(comp == TransformationComp_Rotation || comp == TransformationComp_Scaling || comp == TransformationComp_Translation) {
				continue;
			}

			const aiVector3D& v = PropertyGet<aiVector3D>(props,NameTransformationCompProperty(comp),ok);
			if(ok && v.SquareLength() > zero_epsilon) {
				return true;
			}
		}

		return false;
	}


	// ------------------------------------------------------------------------------------------------
	// note: name must be a FixNodeName() result
	std::string NameTransformationChainNode(const std::string& name, TransformationComp comp)
	{
		return name + std::string(MAGIC_NODE_TAG) + "_" + NameTransformationComp(comp);
	}


	// ------------------------------------------------------------------------------------------------
	/** note: memory for output_nodes will be managed by the caller */
	void GenerateTransformationNodeChain(const Model& model, 
		std::vector<aiNode*>& output_nodes)
	{
		const PropertyTable& props = model.Props();

		// XXX handle different rotation modes
		const RotationMode rot = RotationMode_Euler_XYZ;

		bool ok;

		aiMatrix4x4 chain[TransformationComp_MAXIMUM];
		std::fill_n(chain, static_cast<unsigned int>(TransformationComp_MAXIMUM), aiMatrix4x4());
		
		// generate transformation matrices for all the different transformation components
		const float zero_epsilon = 1e-6f;
		bool is_complex = false;

		const aiVector3D& PreRotation = PropertyGet<aiVector3D>(props,"PreRotation",ok);
		if(ok && PreRotation.SquareLength() > zero_epsilon) {
			is_complex = true;

			GetRotationMatrix(rot, PreRotation, chain[TransformationComp_PreRotation]);
		}

		const aiVector3D& PostRotation = PropertyGet<aiVector3D>(props,"PostRotation",ok);
		if(ok && PostRotation.SquareLength() > zero_epsilon) {
			is_complex = true;
			
			GetRotationMatrix(rot, PostRotation, chain[TransformationComp_PostRotation]);
		}

		const aiVector3D& RotationPivot = PropertyGet<aiVector3D>(props,"RotationPivot",ok);
		if(ok && RotationPivot.SquareLength() > zero_epsilon) {
			is_complex = true;
			
			aiMatrix4x4::Translation(RotationPivot,chain[TransformationComp_RotationPivot]);
			aiMatrix4x4::Translation(-RotationPivot,chain[TransformationComp_RotationPivotInverse]);
		}

		const aiVector3D& RotationOffset = PropertyGet<aiVector3D>(props,"RotationOffset",ok);
		if(ok && RotationOffset.SquareLength() > zero_epsilon) {
			is_complex = true;

			aiMatrix4x4::Translation(RotationOffset,chain[TransformationComp_RotationOffset]);
		}

		const aiVector3D& ScalingOffset = PropertyGet<aiVector3D>(props,"ScalingOffset",ok);
		if(ok && ScalingOffset.SquareLength() > zero_epsilon) {
			is_complex = true;
			
			aiMatrix4x4::Translation(ScalingOffset,chain[TransformationComp_ScalingOffset]);
		}

		const aiVector3D& ScalingPivot = PropertyGet<aiVector3D>(props,"ScalingPivot",ok);
		if(ok && ScalingPivot.SquareLength() > zero_epsilon) {
			is_complex = true;

			aiMatrix4x4::Translation(ScalingPivot,chain[TransformationComp_ScalingPivot]);
			aiMatrix4x4::Translation(-ScalingPivot,chain[TransformationComp_ScalingPivotInverse]);
		}

		const aiVector3D& Translation = PropertyGet<aiVector3D>(props,"Lcl Translation",ok);
		if(ok && Translation.SquareLength() > zero_epsilon) {
			aiMatrix4x4::Translation(Translation,chain[TransformationComp_Translation]);
		}

		const aiVector3D& Scaling = PropertyGet<aiVector3D>(props,"Lcl Scaling",ok);
		if(ok && fabs(Scaling.SquareLength()-1.0f) > zero_epsilon) {
			aiMatrix4x4::Scaling(Scaling,chain[TransformationComp_Scaling]);
		}

		const aiVector3D& Rotation = PropertyGet<aiVector3D>(props,"Lcl Rotation",ok);
		if(ok && Rotation.SquareLength() > zero_epsilon) {
			GetRotationMatrix(rot, Rotation, chain[TransformationComp_Rotation]);
		}

		is_complex = true;

		// is_complex needs to be consistent with NeedsComplexTransformationChain()
		// or the interplay between this code and the animation converter would
		// not be guaranteed.
		ai_assert(NeedsComplexTransformationChain(model) == is_complex);

		const std::string& name = FixNodeName(model.Name());

		// now, if we have more than just Translation, Scaling and Rotation,
		// we need to generate a full node chain to accommodate for assimp's
		// lack to express pivots and offsets.
		if(is_complex && doc.Settings().preservePivots) {
			FBXImporter::LogInfo("generating full transformation chain for node: " + name);

			// query the anim_chain_bits dictionary to find out which chain elements
			// have associated node animation channels. These can not be dropped 
			// even if they have identity transform in bind pose.
			NodeAnimBitMap::const_iterator it = node_anim_chain_bits.find(name);
			const unsigned int anim_chain_bitmask = (it == node_anim_chain_bits.end() ? 0 : (*it).second);

			unsigned int bit = 0x1;
			for (size_t i = 0; i < TransformationComp_MAXIMUM; ++i, bit <<= 1) {
				const TransformationComp comp = static_cast<TransformationComp>(i);
				
				if (chain[i].IsIdentity() && (anim_chain_bitmask & bit) == 0) {
					//continue;
				}

				aiNode* nd = new aiNode();
				output_nodes.push_back(nd);
				
				nd->mName.Set(NameTransformationChainNode(name, comp));
				nd->mTransformation = chain[i];
			}

			ai_assert(output_nodes.size());
			return;
		}

		// else, we can just multiply the matrices together
		aiNode* nd = new aiNode();
		output_nodes.push_back(nd);

		nd->mName.Set(name);

		for (size_t i = 0; i < TransformationComp_MAXIMUM; ++i) {
			nd->mTransformation = nd->mTransformation * chain[i];
		}
	}


	// ------------------------------------------------------------------------------------------------
	void ConvertModel(const Model& model, aiNode& nd)
	{
		const std::vector<const Geometry*>& geos = model.GetGeometry();

		std::vector<unsigned int> meshes;
		meshes.reserve(geos.size());

		BOOST_FOREACH(const Geometry* geo, geos) {

			const MeshGeometry* const mesh = dynamic_cast<const MeshGeometry*>(geo);
			if(mesh) {
				const std::vector<unsigned int>& indices = ConvertMesh(*mesh, model);
				std::copy(indices.begin(),indices.end(),std::back_inserter(meshes) );
			}
			else {
				FBXImporter::LogWarn("ignoring unrecognized geometry: " + geo->Name());
			}
		}

		if(meshes.size()) {
			nd.mMeshes = new unsigned int[meshes.size()]();
			nd.mNumMeshes = static_cast<unsigned int>(meshes.size());

			std::swap_ranges(meshes.begin(),meshes.end(),nd.mMeshes);
		}
	}


	// ------------------------------------------------------------------------------------------------
	// MeshGeometry -> aiMesh, return mesh index + 1 or 0 if the conversion failed
	std::vector<unsigned int> ConvertMesh(const MeshGeometry& mesh, const Model& model)
	{
		std::vector<unsigned int> temp; 

		MeshMap::const_iterator it = meshes_converted.find(&mesh);
		if (it != meshes_converted.end()) {
			std::copy((*it).second.begin(),(*it).second.end(),std::back_inserter(temp));
			return temp;
		}

		const std::vector<aiVector3D>& vertices = mesh.GetVertices();
		const std::vector<unsigned int>& faces = mesh.GetFaceIndexCounts();
		if(vertices.empty() || faces.empty()) {
			FBXImporter::LogWarn("ignoring empty geometry: " + mesh.Name());
			return temp;
		}

		// one material per mesh maps easily to aiMesh. Multiple material 
		// meshes need to be split.
		const std::vector<unsigned int>& mindices = mesh.GetMaterialIndices();
		if (doc.Settings().readMaterials && !mindices.empty()) {
			const unsigned int base = mindices[0];
			BOOST_FOREACH(unsigned int index, mindices) {
				if(index != base) {
					return ConvertMeshMultiMaterial(mesh, model);
				}
			}
		}

		// faster codepath, just copy the data
		temp.push_back(ConvertMeshSingleMaterial(mesh, model));
		return temp;
	}


	// ------------------------------------------------------------------------------------------------
	aiMesh* SetupEmptyMesh(const MeshGeometry& mesh, unsigned int material_index)
	{
		aiMesh* const out_mesh = new aiMesh();
		meshes.push_back(out_mesh);
		meshes_converted[&mesh].push_back(static_cast<unsigned int>(meshes.size()-1));

		// set name
		std::string name = mesh.Name();
		if (name.substr(0,10) == "Geometry::") {
			name = name.substr(10);
		}

		if(name.length()) {
			out_mesh->mName.Set(name);
		}

		return out_mesh;
	}


	// ------------------------------------------------------------------------------------------------
	unsigned int ConvertMeshSingleMaterial(const MeshGeometry& mesh, const Model& model)	
	{
		const std::vector<unsigned int>& mindices = mesh.GetMaterialIndices();
		aiMesh* const out_mesh = SetupEmptyMesh(mesh,mindices.size() ? mindices[0] : static_cast<unsigned int>(-1)); 

		const std::vector<aiVector3D>& vertices = mesh.GetVertices();
		const std::vector<unsigned int>& faces = mesh.GetFaceIndexCounts();

		// copy vertices
		out_mesh->mNumVertices = static_cast<unsigned int>(vertices.size());
		out_mesh->mVertices = new aiVector3D[vertices.size()];
		std::copy(vertices.begin(),vertices.end(),out_mesh->mVertices);

		// generate dummy faces
		out_mesh->mNumFaces = static_cast<unsigned int>(faces.size());
		aiFace* fac = out_mesh->mFaces = new aiFace[faces.size()]();

		unsigned int cursor = 0;
		BOOST_FOREACH(unsigned int pcount, faces) {
			aiFace& f = *fac++;
			f.mNumIndices = pcount;
			f.mIndices = new unsigned int[pcount];
			switch(pcount) 
			{
			case 1:
				out_mesh->mPrimitiveTypes |= aiPrimitiveType_POINT;
				break;
			case 2:
				out_mesh->mPrimitiveTypes |= aiPrimitiveType_LINE;
				break;
			case 3:
				out_mesh->mPrimitiveTypes |= aiPrimitiveType_TRIANGLE;
				break;
			default:
				out_mesh->mPrimitiveTypes |= aiPrimitiveType_POLYGON;
				break;
			}
			for (unsigned int i = 0; i < pcount; ++i) {
				f.mIndices[i] = cursor++;
			}
		}

		// copy normals
		const std::vector<aiVector3D>& normals = mesh.GetNormals();
		if(normals.size()) {
			ai_assert(normals.size() == vertices.size());

			out_mesh->mNormals = new aiVector3D[vertices.size()];
			std::copy(normals.begin(),normals.end(),out_mesh->mNormals);
		}

		// copy tangents - assimp requires both tangents and bitangents (binormals)
		// to be present, or neither of them. Compute binormals from normals
		// and tangents if needed.
		const std::vector<aiVector3D>& tangents = mesh.GetTangents();
		const std::vector<aiVector3D>* binormals = &mesh.GetBinormals();

		if(tangents.size()) {
			std::vector<aiVector3D> tempBinormals;
			if (!binormals->size()) {
				if (normals.size()) {
					tempBinormals.resize(normals.size());
					for (unsigned int i = 0; i < tangents.size(); ++i) {
						tempBinormals[i] = normals[i] ^ tangents[i];
					}

					binormals = &tempBinormals;
				}
				else {
					binormals = NULL;	
				}
			}

			if(binormals) {
				ai_assert(tangents.size() == vertices.size() && binormals->size() == vertices.size());

				out_mesh->mTangents = new aiVector3D[vertices.size()];
				std::copy(tangents.begin(),tangents.end(),out_mesh->mTangents);

				out_mesh->mBitangents = new aiVector3D[vertices.size()];
				std::copy(binormals->begin(),binormals->end(),out_mesh->mBitangents);
			}
		}

		// copy texture coords
		for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++i) {
			const std::vector<aiVector2D>& uvs = mesh.GetTextureCoords(i);
			if(uvs.empty()) {
				break;
			}

			aiVector3D* out_uv = out_mesh->mTextureCoords[i] = new aiVector3D[vertices.size()];
			BOOST_FOREACH(const aiVector2D& v, uvs) {
				*out_uv++ = aiVector3D(v.x,v.y,0.0f);
			}

			out_mesh->mNumUVComponents[i] = 2;
		}

		// copy vertex colors
		for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_COLOR_SETS; ++i) {
			const std::vector<aiColor4D>& colors = mesh.GetVertexColors(i);
			if(colors.empty()) {
				break;
			}

			out_mesh->mColors[i] = new aiColor4D[vertices.size()];
			std::copy(colors.begin(),colors.end(),out_mesh->mColors[i]);
		}

		if(!doc.Settings().readMaterials || mindices.empty()) {
			FBXImporter::LogError("no material assigned to mesh, setting default material");
			out_mesh->mMaterialIndex = GetDefaultMaterial();
		}
		else {
			ConvertMaterialForMesh(out_mesh,model,mesh,mindices[0]);
		}

		if(doc.Settings().readWeights && mesh.DeformerSkin() != NULL) {
			ConvertWeights(out_mesh, model, mesh, NO_MATERIAL_SEPARATION);
		}

		return static_cast<unsigned int>(meshes.size() - 1);
	}


	// ------------------------------------------------------------------------------------------------
	std::vector<unsigned int> ConvertMeshMultiMaterial(const MeshGeometry& mesh, const Model& model)	
	{
		const std::vector<unsigned int>& mindices = mesh.GetMaterialIndices();
		ai_assert(mindices.size());
	
		std::set<unsigned int> had;
		std::vector<unsigned int> indices;

		BOOST_FOREACH(unsigned int index, mindices) {
			if(had.find(index) == had.end()) {

				indices.push_back(ConvertMeshMultiMaterial(mesh, model, index));
				had.insert(index);
			}
		}

		return indices;
	}


	// ------------------------------------------------------------------------------------------------
	unsigned int ConvertMeshMultiMaterial(const MeshGeometry& mesh, const Model& model, unsigned int index)	
	{
		aiMesh* const out_mesh = SetupEmptyMesh(mesh, index);

		const std::vector<unsigned int>& mindices = mesh.GetMaterialIndices();
		const std::vector<aiVector3D>& vertices = mesh.GetVertices();
		const std::vector<unsigned int>& faces = mesh.GetFaceIndexCounts();

		const bool process_weights = doc.Settings().readWeights && mesh.DeformerSkin() != NULL;

		unsigned int count_faces = 0;
		unsigned int count_vertices = 0;

		// count faces
		for(std::vector<unsigned int>::const_iterator it = mindices.begin(), 
			end = mindices.end(), itf = faces.begin(); it != end; ++it, ++itf) 
		{	
			if ((*it) != index) {
				continue;
			}
			++count_faces;
			count_vertices += *itf;
		}

		ai_assert(count_faces);
		ai_assert(count_vertices);

		// mapping from output indices to DOM indexing, needed to resolve weights
		std::vector<unsigned int> reverseMapping;

		if (process_weights) {
			reverseMapping.resize(count_vertices);
		}

		// allocate output data arrays, but don't fill them yet
		out_mesh->mNumVertices = count_vertices;
		out_mesh->mVertices = new aiVector3D[count_vertices];

		out_mesh->mNumFaces = count_faces;
		aiFace* fac = out_mesh->mFaces = new aiFace[count_faces]();


		// allocate normals
		const std::vector<aiVector3D>& normals = mesh.GetNormals();
		if(normals.size()) {
			ai_assert(normals.size() == vertices.size());
			out_mesh->mNormals = new aiVector3D[vertices.size()];
		}

		// allocate tangents, binormals. 
		const std::vector<aiVector3D>& tangents = mesh.GetTangents();
		const std::vector<aiVector3D>* binormals = &mesh.GetBinormals();

		if(tangents.size()) {
			std::vector<aiVector3D> tempBinormals;
			if (!binormals->size()) {
				if (normals.size()) {
					// XXX this computes the binormals for the entire mesh, not only 
					// the part for which we need them.
					tempBinormals.resize(normals.size());
					for (unsigned int i = 0; i < tangents.size(); ++i) {
						tempBinormals[i] = normals[i] ^ tangents[i];
					}

					binormals = &tempBinormals;
				}
				else {
					binormals = NULL;	
				}
			}

			if(binormals) {
				ai_assert(tangents.size() == vertices.size() && binormals->size() == vertices.size());

				out_mesh->mTangents = new aiVector3D[vertices.size()];
				out_mesh->mBitangents = new aiVector3D[vertices.size()];
			}
		}

		// allocate texture coords
		unsigned int num_uvs = 0;
		for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++i, ++num_uvs) {
			const std::vector<aiVector2D>& uvs = mesh.GetTextureCoords(i);
			if(uvs.empty()) {
				break;
			}

			out_mesh->mTextureCoords[i] = new aiVector3D[vertices.size()];
			out_mesh->mNumUVComponents[i] = 2;
		}

		// allocate vertex colors
		unsigned int num_vcs = 0;
		for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_COLOR_SETS; ++i, ++num_vcs) {
			const std::vector<aiColor4D>& colors = mesh.GetVertexColors(i);
			if(colors.empty()) {
				break;
			}

			out_mesh->mColors[i] = new aiColor4D[vertices.size()];
		}

		unsigned int cursor = 0, in_cursor = 0;

		for(std::vector<unsigned int>::const_iterator it = mindices.begin(), 
			end = mindices.end(), itf = faces.begin(); it != end; ++it, ++itf) 
		{	
			const unsigned int pcount = *itf;
			if ((*it) != index) {
				in_cursor += pcount;
				continue;
			}

			aiFace& f = *fac++;

			f.mNumIndices = pcount;
			f.mIndices = new unsigned int[pcount];
			switch(pcount) 
			{
			case 1:
				out_mesh->mPrimitiveTypes |= aiPrimitiveType_POINT;
				break;
			case 2:
				out_mesh->mPrimitiveTypes |= aiPrimitiveType_LINE;
				break;
			case 3:
				out_mesh->mPrimitiveTypes |= aiPrimitiveType_TRIANGLE;
				break;
			default:
				out_mesh->mPrimitiveTypes |= aiPrimitiveType_POLYGON;
				break;
			}
			for (unsigned int i = 0; i < pcount; ++i, ++cursor, ++in_cursor) {
				f.mIndices[i] = cursor;

				if(reverseMapping.size()) {
					reverseMapping[cursor] = in_cursor;
				}

				out_mesh->mVertices[cursor] = vertices[in_cursor];

				if(out_mesh->mNormals) {
					out_mesh->mNormals[cursor] = normals[in_cursor];
				}

				if(out_mesh->mTangents) {
					out_mesh->mTangents[cursor] = tangents[in_cursor];
					out_mesh->mBitangents[cursor] = (*binormals)[in_cursor];
				}

				for (unsigned int i = 0; i < num_uvs; ++i) {
					const std::vector<aiVector2D>& uvs = mesh.GetTextureCoords(i);
					out_mesh->mTextureCoords[i][cursor] = aiVector3D(uvs[in_cursor].x,uvs[in_cursor].y, 0.0f);
				}

				for (unsigned int i = 0; i < num_vcs; ++i) {
					const std::vector<aiColor4D>& cols = mesh.GetVertexColors(i);
					out_mesh->mColors[i][cursor] = cols[in_cursor];
				}
			}
		}
	
		ConvertMaterialForMesh(out_mesh,model,mesh,index);

		if(process_weights) {
			ConvertWeights(out_mesh, model, mesh, index, &reverseMapping);
		}

		return static_cast<unsigned int>(meshes.size() - 1);
	}

	static const unsigned int NO_MATERIAL_SEPARATION = /* std::numeric_limits<unsigned int>::max() */ 
		static_cast<unsigned int>(-1);


	// ------------------------------------------------------------------------------------------------
	/** - if materialIndex == NO_MATERIAL_SEPARATION, materials are not taken into
	 *  account when determining which weights to include. 
	 *  - outputVertStartIndices is only used when a material index is specified, it gives for
	 *    each output vertex the DOM index it maps to. */
	void ConvertWeights(aiMesh* out, const Model& model, const MeshGeometry& geo, 
		unsigned int materialIndex = NO_MATERIAL_SEPARATION, 
		std::vector<unsigned int>* outputVertStartIndices = NULL)
	{
		ai_assert(geo.DeformerSkin());

		std::vector<size_t> out_indices;
		std::vector<size_t> index_out_indices;
		std::vector<size_t> count_out_indices;

		const Skin& sk = *geo.DeformerSkin();

		std::vector<aiBone*> bones;
		bones.reserve(sk.Clusters().size());

		const bool no_mat_check = materialIndex == NO_MATERIAL_SEPARATION;
		ai_assert(no_mat_check || outputVertStartIndices);

		try {

			BOOST_FOREACH(const Cluster* cluster, sk.Clusters()) {
				ai_assert(cluster);

				const WeightIndexArray& indices = cluster->GetIndices();
				const WeightArray& weights = cluster->GetWeights();

				if(indices.empty()) {
					continue;
				}

				const MatIndexArray& mats = geo.GetMaterialIndices();

				bool ok = false;		

				const size_t no_index_sentinel = std::numeric_limits<size_t>::max();

				count_out_indices.clear();
				index_out_indices.clear();
				out_indices.clear();

				// now check if *any* of these weights is contained in the output mesh,
				// taking notes so we don't need to do it twice.
				BOOST_FOREACH(WeightIndexArray::value_type index, indices) {

					unsigned int count;
					const unsigned int* const out_idx = geo.ToOutputVertexIndex(index, count);

					index_out_indices.push_back(no_index_sentinel);
					count_out_indices.push_back(0);

					for(unsigned int i = 0; i < count; ++i) {					
						if (no_mat_check || mats[geo.FaceForVertexIndex(out_idx[i])] == materialIndex) {
							
							if (index_out_indices.back() == no_index_sentinel) {
								index_out_indices.back() = out_indices.size();
								
							}

							if (no_mat_check) {
								out_indices.push_back(out_idx[i]);
							}
							else {
								// this extra lookup is in O(logn), so the entire algorithm becomes O(nlogn)
								const std::vector<unsigned int>::iterator it = std::lower_bound(
									outputVertStartIndices->begin(),
									outputVertStartIndices->end(),
									out_idx[i]
								);

								out_indices.push_back(std::distance(outputVertStartIndices->begin(), it));
							}

							++count_out_indices.back();
							ok = true;
						}
					}		
				}

				// if we found at least one, generate the output bones
				// XXX this could be heavily simplified by collecting the bone
				// data in a single step.
				if (ok) {
					ConvertCluster(bones, *cluster, out_indices, index_out_indices, count_out_indices);
				}
			}
		}
		catch (std::exception&) {
			std::for_each(bones.begin(),bones.end(),Util::delete_fun<aiBone>());
			throw;
		}

		if(bones.empty()) {
			return;
		}

		out->mBones = new aiBone*[bones.size()]();
		out->mNumBones = static_cast<unsigned int>(bones.size());

		std::swap_ranges(bones.begin(),bones.end(),out->mBones);
	}


	// ------------------------------------------------------------------------------------------------
	void ConvertCluster(std::vector<aiBone*>& bones, const Cluster& cl, 		
		std::vector<size_t>& out_indices,
		std::vector<size_t>& index_out_indices,
		std::vector<size_t>& count_out_indices
		)
	{
		aiBone* const bone = new aiBone();
		bones.push_back(bone);

		bone->mName = FixNodeName(cl.TargetNode()->Name());
		bone->mOffsetMatrix = cl.TransformLink();
		bone->mOffsetMatrix.Inverse();

		bone->mNumWeights = static_cast<unsigned int>(out_indices.size());
		aiVertexWeight* cursor = bone->mWeights = new aiVertexWeight[out_indices.size()];

		const size_t no_index_sentinel = std::numeric_limits<size_t>::max();
		const WeightArray& weights = cl.GetWeights();

		const size_t c = index_out_indices.size();
		for (size_t i = 0; i < c; ++i) {
			const size_t index_index =  index_out_indices[i];

			if (index_index == no_index_sentinel) {
				continue;
			}

			const size_t cc = count_out_indices[i];
			for (size_t j = 0; j < cc; ++j) {
				aiVertexWeight& out_weight = *cursor++;

				out_weight.mVertexId = static_cast<unsigned int>(out_indices[index_index + j]);
				out_weight.mWeight = weights[i];
			}			
		}
	}


	// ------------------------------------------------------------------------------------------------
	void ConvertMaterialForMesh(aiMesh* out, const Model& model, const MeshGeometry& geo, unsigned int materialIndex)
	{
		// locate source materials for this mesh
		const std::vector<const Material*>& mats = model.GetMaterials();
		if (materialIndex >= mats.size()) {
			FBXImporter::LogError("material index out of bounds, setting default material");
			out->mMaterialIndex = GetDefaultMaterial();
			return;
		}

		const Material* const mat = mats[materialIndex];
		MaterialMap::const_iterator it = materials_converted.find(mat);
		if (it != materials_converted.end()) {
			out->mMaterialIndex = (*it).second;
			return;
		}

		out->mMaterialIndex = ConvertMaterial(*mat);	
		materials_converted[mat] = out->mMaterialIndex;
	}


	// ------------------------------------------------------------------------------------------------
	unsigned int GetDefaultMaterial()
	{
		if (defaultMaterialIndex) {
			return defaultMaterialIndex - 1; 
		}

		aiMaterial* out_mat = new aiMaterial();
		materials.push_back(out_mat);

		const aiColor3D diffuse = aiColor3D(0.8f,0.8f,0.8f);
		out_mat->AddProperty(&diffuse,1,AI_MATKEY_COLOR_DIFFUSE);

		aiString s;
		s.Set(AI_DEFAULT_MATERIAL_NAME);

		out_mat->AddProperty(&s,AI_MATKEY_NAME);

		defaultMaterialIndex = static_cast<unsigned int>(materials.size());
		return defaultMaterialIndex - 1;
	}


	// ------------------------------------------------------------------------------------------------
	// Material -> aiMaterial
	unsigned int ConvertMaterial(const Material& material)
	{
		const PropertyTable& props = material.Props();

		// generate empty output material
		aiMaterial* out_mat = new aiMaterial();
		materials_converted[&material] = static_cast<unsigned int>(materials.size());

		materials.push_back(out_mat);

		aiString str;

		// stip Material:: prefix
		std::string name = material.Name();
		if(name.substr(0,10) == "Material::") {
			name = name.substr(10);
		}

		// set material name if not empty - this could happen
		// and there should be no key for it in this case.
		if(name.length()) {
			str.Set(name);
			out_mat->AddProperty(&str,AI_MATKEY_NAME);
		}

		// shading stuff and colors
		SetShadingPropertiesCommon(out_mat,props);
	
		// texture assignments
		SetTextureProperties(out_mat,material.Textures());

		return static_cast<unsigned int>(materials.size() - 1);
	}


	// ------------------------------------------------------------------------------------------------
	void TrySetTextureProperties(aiMaterial* out_mat, const TextureMap& textures, const std::string& propName, aiTextureType target)
	{
		TextureMap::const_iterator it = textures.find(propName);
		if(it == textures.end()) {
			return;
		}

		const Texture* const tex = (*it).second;
		
		aiString path;
		path.Set(tex->RelativeFilename());

		out_mat->AddProperty(&path,_AI_MATKEY_TEXTURE_BASE,target,0);

		aiUVTransform uvTrafo;
		// XXX handle all kinds of UV transformations
		uvTrafo.mScaling = tex->UVScaling();
		uvTrafo.mTranslation = tex->UVTranslation();
		out_mat->AddProperty(&uvTrafo,1,_AI_MATKEY_UVTRANSFORM_BASE,target,0);

		const PropertyTable& props = tex->Props();

		int uvIndex = 0;

		bool ok;
		const std::string& uvSet = PropertyGet<std::string>(props,"UVSet",ok);
		if(ok) {
			// "default" is the name which usually appears in the FbxFileTexture template
			if(uvSet != "default" && uvSet.length()) {
				// this is a bit awkward - we need to find a mesh that uses this
				// material and scan its UV channels for the given UV name because
				// assimp references UV channels by index, not by name.

				// XXX: the case that UV channels may appear in different orders
				// in meshes is unhandled. A possible solution would be to sort
				// the UV channels alphabetically, but this would have the side
				// effect that the primary (first) UV channel would sometimes
				// be moved, causing trouble when users read only the first
				// UV channel and ignore UV channel assignments altogether.

				const unsigned int matIndex = static_cast<unsigned int>(std::distance(materials.begin(), 
					std::find(materials.begin(),materials.end(),out_mat)
				));

				uvIndex = -1;
				BOOST_FOREACH(const MeshMap::value_type& v,meshes_converted) {
					const MeshGeometry* const mesh = dynamic_cast<const MeshGeometry*> (v.first);
					if(!mesh) {
						continue;
					}

					const std::vector<unsigned int>& mats = mesh->GetMaterialIndices();
					if(std::find(mats.begin(),mats.end(),matIndex) == mats.end()) {
						continue;
					}

					int index = -1;
					for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++i) {
						if(mesh->GetTextureCoords(i).empty()) {
							break;
						}
						const std::string& name = mesh->GetTextureCoordChannelName(i);
						if(name == uvSet) {
							index = static_cast<int>(i);
							break;
						}
					}
					if(index == -1) {
						FBXImporter::LogWarn("did not find UV channel named " + uvSet + " in a mesh using this material");
						continue;
					}

					if(uvIndex == -1) {
						uvIndex = index;
					}
					else {
						FBXImporter::LogWarn("the UV channel named " + uvSet + 
							" appears at different positions in meshes, results will be wrong");
					}
				}

				if(uvIndex == -1) {
					FBXImporter::LogWarn("failed to resolve UV channel " + uvSet + ", using first UV channel");
					uvIndex = 0;
				}
			}
		}

		out_mat->AddProperty(&uvIndex,1,_AI_MATKEY_UVWSRC_BASE,target,0);
	}


	// ------------------------------------------------------------------------------------------------
	void SetTextureProperties(aiMaterial* out_mat, const TextureMap& textures)
	{
		TrySetTextureProperties(out_mat, textures, "DiffuseColor", aiTextureType_DIFFUSE);
		TrySetTextureProperties(out_mat, textures, "AmbientColor", aiTextureType_AMBIENT);
		TrySetTextureProperties(out_mat, textures, "EmissiveColor", aiTextureType_EMISSIVE);
		TrySetTextureProperties(out_mat, textures, "SpecularColor", aiTextureType_SPECULAR);
		TrySetTextureProperties(out_mat, textures, "TransparentColor", aiTextureType_OPACITY);
		TrySetTextureProperties(out_mat, textures, "ReflectionColor", aiTextureType_REFLECTION);
		TrySetTextureProperties(out_mat, textures, "DisplacementColor", aiTextureType_DISPLACEMENT);
		TrySetTextureProperties(out_mat, textures, "NormalMap", aiTextureType_NORMALS);
		TrySetTextureProperties(out_mat, textures, "Bump", aiTextureType_HEIGHT);
	}



	// ------------------------------------------------------------------------------------------------
	aiColor3D GetColorPropertyFromMaterial(const PropertyTable& props,const std::string& baseName, bool& result)
	{
		result = true;

		bool ok;
		const aiVector3D& Diffuse = PropertyGet<aiVector3D>(props,baseName,ok);
		if(ok) {
			return aiColor3D(Diffuse.x,Diffuse.y,Diffuse.z);
		}
		else {
			aiVector3D DiffuseColor = PropertyGet<aiVector3D>(props,baseName + "Color",ok);
			if(ok) {
				float DiffuseFactor = PropertyGet<float>(props,baseName + "Factor",ok);
				if(ok) {
					DiffuseColor *= DiffuseFactor;
				}

				return aiColor3D(DiffuseColor.x,DiffuseColor.y,DiffuseColor.z);
			}
		}
		result = false;
		return aiColor3D(0.0f,0.0f,0.0f);
	}


	// ------------------------------------------------------------------------------------------------
	void SetShadingPropertiesCommon(aiMaterial* out_mat, const PropertyTable& props)
	{
		// set shading properties. There are various, redundant ways in which FBX materials
		// specify their shading settings (depending on shading models, prop
		// template etc.). No idea which one is right in a particular context. 
		// Just try to make sense of it - there's no spec to verify this against, 
		// so why should we.
		bool ok;
		const aiColor3D& Diffuse = GetColorPropertyFromMaterial(props,"Diffuse",ok);
		if(ok) {
			out_mat->AddProperty(&Diffuse,1,AI_MATKEY_COLOR_DIFFUSE);
		}

		const aiColor3D& Emissive = GetColorPropertyFromMaterial(props,"Emissive",ok);
		if(ok) {
			out_mat->AddProperty(&Emissive,1,AI_MATKEY_COLOR_EMISSIVE);
		}

		const aiColor3D& Ambient = GetColorPropertyFromMaterial(props,"Ambient",ok);
		if(ok) {
			out_mat->AddProperty(&Ambient,1,AI_MATKEY_COLOR_AMBIENT);
		}

		const aiColor3D& Specular = GetColorPropertyFromMaterial(props,"Specular",ok);
		if(ok) {
			out_mat->AddProperty(&Specular,1,AI_MATKEY_COLOR_SPECULAR);
		}

		const float Opacity = PropertyGet<float>(props,"Opacity",ok);
		if(ok) {
			out_mat->AddProperty(&Opacity,1,AI_MATKEY_OPACITY);
		}

		const float Reflectivity = PropertyGet<float>(props,"Reflectivity",ok);
		if(ok) {
			out_mat->AddProperty(&Reflectivity,1,AI_MATKEY_REFLECTIVITY);
		}

		const float Shininess = PropertyGet<float>(props,"Shininess",ok);
		if(ok) {
			out_mat->AddProperty(&Shininess,1,AI_MATKEY_SHININESS_STRENGTH);
		}

		const float ShininessExponent = PropertyGet<float>(props,"ShininessExponent",ok);
		if(ok) {
			out_mat->AddProperty(&ShininessExponent,1,AI_MATKEY_SHININESS);
		}
	}


	// ------------------------------------------------------------------------------------------------
	// convert animation data to aiAnimation et al
	void ConvertAnimations() 
	{
		const std::vector<const AnimationStack*>& animations = doc.AnimationStacks();
		BOOST_FOREACH(const AnimationStack* stack, animations) {
			ConvertAnimationStack(*stack);
		}
	}


	// ------------------------------------------------------------------------------------------------
	std::string FixNodeName(const std::string& name)
	{
		// strip Model:: prefix, avoiding ambiguities (i.e. don't strip if 
		// this causes ambiguities, well possible between empty identifiers,
		// such as "Model::" and ""). Make sure the behaviour is consistent
		// across multiple calls to FixNodeName().
		if(name.substr(0,7) == "Model::") {
			std::string temp = name.substr(7);

			const NodeNameMap::const_iterator it = node_names.find(temp);
			if (it != node_names.end()) {
				if (!(*it).second) {
					return FixNodeName(name + "_");
				}
			}
			node_names[temp] = true;
			return temp;
		}

		const NodeNameMap::const_iterator it = node_names.find(name);
		if (it != node_names.end()) {
			if ((*it).second) {
				return FixNodeName(name + "_");
			}
		}
		node_names[name] = false;
		return name;
	}


	typedef std::map<const AnimationCurveNode*, const AnimationLayer*> LayerMap;

	// XXX: better use multi_map ..
	typedef std::map<std::string, std::vector<const AnimationCurveNode*> > NodeMap;


	// ------------------------------------------------------------------------------------------------
	void ConvertAnimationStack(const AnimationStack& st)
	{				
		const AnimationLayerList& layers = st.Layers();
		if(layers.empty()) {
			return;
		}

		aiAnimation* const anim = new aiAnimation();
		animations.push_back(anim);

		// strip AnimationStack:: prefix
		std::string name = st.Name();
		if(name.substr(0,16) == "AnimationStack::") {
			name = name.substr(16);
		}

		anim->mName.Set(name);
		
		// need to find all nodes for which we need to generate node animations -
		// it may happen that we need to merge multiple layers, though.
		NodeMap node_map;

		// reverse mapping from curves to layers, much faster than querying 
		// the FBX DOM for it.
		LayerMap layer_map;
		
		BOOST_FOREACH(const AnimationLayer* layer, layers) {
			ai_assert(layer);

			const AnimationCurveNodeList& nodes = layer->Nodes();
			BOOST_FOREACH(const AnimationCurveNode* node, nodes) {
				ai_assert(node);

				const Model* const model = dynamic_cast<const Model*>(node->Target());
				// this can happen - it could also be a NodeAttribute (i.e. for camera animations)
				if(!model) {
					continue;
				}

				const std::string& name = FixNodeName(model->Name());
				node_map[name].push_back(node);

				layer_map[node] = layer;
			}
		}

		// generate node animations
		std::vector<aiNodeAnim*> node_anims;

		double min_time = 1e10;
		double max_time = -1e10;

		try {
			BOOST_FOREACH(const NodeMap::value_type& kv, node_map) {
				GenerateNodeAnimations(node_anims, 
					kv.first, 
					kv.second, 
					layer_map, 
					max_time, 
					min_time);
			}
		}
		catch(std::exception&) {
			std::for_each(node_anims.begin(), node_anims.end(), Util::delete_fun<aiNodeAnim>());
			throw;
		}

		if(node_anims.size()) {
			anim->mChannels = new aiNodeAnim*[node_anims.size()]();
			anim->mNumChannels = static_cast<unsigned int>(node_anims.size());

			std::swap_ranges(node_anims.begin(),node_anims.end(),anim->mChannels);
		}
		else {
			// empty animations would fail validation, so drop them
			delete anim;
			animations.pop_back();
			FBXImporter::LogInfo("ignoring empty AnimationStack: " + name);
			return;
		}

		// for some mysterious reason, mDuration is simply the maximum key -- the
		// validator always assumes animations to start at zero.
		anim->mDuration = max_time /*- min_time */;
		anim->mTicksPerSecond = 1000.0;
	}


	// ------------------------------------------------------------------------------------------------
	void GenerateNodeAnimations(std::vector<aiNodeAnim*>& node_anims, 
		const std::string& fixed_name, 
		const std::vector<const AnimationCurveNode*>& curves, 
		const LayerMap& layer_map, 
		double& max_time,
		double& min_time)
	{

		NodeMap node_property_map;
		ai_assert(curves.size());

		// sanity check whether the input is ok
#ifdef _DEBUG
		{ const Object* target = NULL;
		BOOST_FOREACH(const AnimationCurveNode* node, curves) {
			if(!target) {
				target = node->Target();
			}
			ai_assert(node->Target() == target);
		}}
#endif

		const AnimationCurveNode* curve_node;
		BOOST_FOREACH(const AnimationCurveNode* node, curves) {
			ai_assert(node);

			if (node->TargetProperty().empty()) {
				FBXImporter::LogWarn("target property for animation curve not set");
				continue;
			}

			curve_node = node;
			if (node->Curves().empty()) {
				FBXImporter::LogWarn("no animation curves assigned to AnimationCurveNode");
				continue;
			}

			node_property_map[node->TargetProperty()].push_back(node);
		}

		ai_assert(curve_node);
		ai_assert(curve_node->TargetAsModel());

		const Model& target = *curve_node->TargetAsModel();

		// check for all possible transformation components
		NodeMap::const_iterator chain[TransformationComp_MAXIMUM];

		bool has_any = false;
		bool has_complex = false;

		for (size_t i = 0; i < TransformationComp_MAXIMUM; ++i) {
			const TransformationComp comp = static_cast<TransformationComp>(i);

			// inverse pivots don't exist in the input, we just generate them
			if (comp == TransformationComp_RotationPivotInverse || comp == TransformationComp_ScalingPivotInverse) {
				chain[i] = node_property_map.end();
				continue;
			}

			chain[i] = node_property_map.find(NameTransformationCompProperty(comp));
			if (chain[i] != node_property_map.end()) {

				// check if this curves contains redundant information by looking
				// up the corresponding node's transformation chain.
				if (doc.Settings().optimizeEmptyAnimationCurves && IsRedundantAnimationData(target, comp, (*chain[i]).second)) {
					FBXImporter::LogDebug("dropping redundant animation channel for node " + target.Name());
					continue;
				}

				has_any = true;

				if (comp != TransformationComp_Rotation && comp != TransformationComp_Scaling &&
					comp != TransformationComp_Translation) {

					has_complex = true;
				}
			}
		}

		if (!has_any) {
			FBXImporter::LogWarn("ignoring node animation, did not find any transformation key frames");
			return;
		}

		// this needs to play nicely with GenerateTransformationNodeChain() which will
		// be invoked _later_ (animations come first). If this node has only rotation,
		// scaling and translation _and_ there are no animated other components either,
		// we can use a single node and also a single node animation channel.
		if (!has_complex && !NeedsComplexTransformationChain(target)) {

			aiNodeAnim* const nd = GenerateSimpleNodeAnim(fixed_name, target, chain, 
				node_property_map.end(), 
				layer_map,
				max_time,
				min_time
				);

			ai_assert(nd);
			node_anims.push_back(nd);
			return;
		}

		// otherwise, things get gruesome and we need separate animation channels
		// for each part of the transformation chain. Remember which channels
		// we generated and pass this information to the node conversion
		// code to avoid nodes that have identity transform, but non-identity
		// animations, being dropped.
		unsigned int flags = 0, bit = 0x1;
		for (size_t i = 0; i < TransformationComp_MAXIMUM; ++i, bit <<= 1) {
			const TransformationComp comp = static_cast<TransformationComp>(i);

			if (chain[i] != node_property_map.end()) {
				flags |= bit;

				ai_assert(comp != TransformationComp_RotationPivotInverse);
				ai_assert(comp != TransformationComp_ScalingPivotInverse);

				const std::string& chain_name = NameTransformationChainNode(fixed_name, comp);

				aiNodeAnim* na;
				switch(comp) 
				{
				case TransformationComp_Rotation:
				case TransformationComp_PreRotation:
				case TransformationComp_PostRotation:
					na = GenerateRotationNodeAnim(chain_name, 
						target, 
						(*chain[i]).second,
						layer_map,
						max_time,
						min_time
						);
					break;

				case TransformationComp_RotationOffset:
				case TransformationComp_RotationPivot:
				case TransformationComp_ScalingOffset:
				case TransformationComp_ScalingPivot:
				case TransformationComp_Translation:
					na = GenerateTranslationNodeAnim(chain_name, 
						target, 
						(*chain[i]).second,
						layer_map,
						max_time,
						min_time);

					// pivoting requires us to generate an implicit inverse channel to undo the pivot translation
					if (comp == TransformationComp_RotationPivot) {
						const std::string& invName = NameTransformationChainNode(fixed_name, TransformationComp_RotationPivotInverse);
						aiNodeAnim* const inv = GenerateTranslationNodeAnim(invName, 
							target, 
							(*chain[i]).second,
							layer_map,
							max_time,
							min_time,
							true);

						ai_assert(inv);
						node_anims.push_back(inv);

						ai_assert(TransformationComp_RotationPivotInverse > i);
						flags |= bit << (TransformationComp_RotationPivotInverse - i);
					}
					else if (comp == TransformationComp_ScalingPivot) {
						const std::string& invName = NameTransformationChainNode(fixed_name, TransformationComp_ScalingPivotInverse);
						aiNodeAnim* const inv = GenerateTranslationNodeAnim(invName, 
							target, 
							(*chain[i]).second,
							layer_map,
							max_time,
							min_time,
							true);

						ai_assert(inv);
						node_anims.push_back(inv);
					
						ai_assert(TransformationComp_RotationPivotInverse > i);
						flags |= bit << (TransformationComp_RotationPivotInverse - i);
					}

					break;

				case TransformationComp_Scaling:
					na = GenerateScalingNodeAnim(chain_name, 
						target, 
						(*chain[i]).second,
						layer_map,
						max_time,
						min_time
						);
					break;

				default:
					ai_assert(false);
				}

				ai_assert(na);
				node_anims.push_back(na);
				continue;
			}
		}

		node_anim_chain_bits[fixed_name] = flags;
	}


	// ------------------------------------------------------------------------------------------------
	bool IsRedundantAnimationData(const Model& target, 
		TransformationComp comp, 
		const std::vector<const AnimationCurveNode*>& curves)
	{
		ai_assert(curves.size());

		// look for animation nodes with
		//  * sub channels for all relevant components set
		//  * one key/value pair per component
		//  * combined values match up the corresponding value in the bind pose node transformation
		// only such nodes are 'redundant' for this function.

		if (curves.size() > 1) {
			return false;
		}

		const AnimationCurveNode& nd = *curves.front();
		const AnimationCurveMap& sub_curves = nd.Curves();

		const AnimationCurveMap::const_iterator dx = sub_curves.find("d|X");
		const AnimationCurveMap::const_iterator dy = sub_curves.find("d|Y");
		const AnimationCurveMap::const_iterator dz = sub_curves.find("d|Z");

		if (dx == sub_curves.end() || dy == sub_curves.end() || dz == sub_curves.end()) {
			return false;
		}

		const KeyValueList& vx = (*dx).second->GetValues();
		const KeyValueList& vy = (*dy).second->GetValues();
		const KeyValueList& vz = (*dz).second->GetValues();

		if(vx.size() != 1 || vy.size() != 1 || vz.size() != 1) {
			return false;
		}

		const aiVector3D dyn_val = aiVector3D(vx[0], vy[0], vz[0]);
		const aiVector3D& static_val = PropertyGet<aiVector3D>(target.Props(), 
			NameTransformationCompProperty(comp), 
			TransformationCompDefaultValue(comp)
		);

		const float epsilon = 1e-6f;
		return (dyn_val - static_val).SquareLength() < epsilon;
	}


	// ------------------------------------------------------------------------------------------------
	aiNodeAnim* GenerateRotationNodeAnim(const std::string& name, 
		const Model& target, 
		const std::vector<const AnimationCurveNode*>& curves,
		const LayerMap& layer_map,
		double& max_time,
		double& min_time)
	{
		ScopeGuard<aiNodeAnim> na(new aiNodeAnim());
		na->mNodeName.Set(name);

		ConvertRotationKeys(na, curves, layer_map, max_time,min_time);

		// dummy scaling key
		na->mScalingKeys = new aiVectorKey[1];
		na->mNumScalingKeys = 1;

		na->mScalingKeys[0].mTime = 0.;
		na->mScalingKeys[0].mValue = aiVector3D(1.0f,1.0f,1.0f);

		// dummy position key
		na->mPositionKeys = new aiVectorKey[1];
		na->mNumPositionKeys = 1;

		na->mPositionKeys[0].mTime = 0.;
		na->mPositionKeys[0].mValue = aiVector3D();

		return na.dismiss();
	}


	// ------------------------------------------------------------------------------------------------
	aiNodeAnim* GenerateScalingNodeAnim(const std::string& name, 
		const Model& target, 
		const std::vector<const AnimationCurveNode*>& curves,
		const LayerMap& layer_map,
		double& max_time,
		double& min_time)
	{
		ScopeGuard<aiNodeAnim> na(new aiNodeAnim());
		na->mNodeName.Set(name);

		ConvertScaleKeys(na, curves, layer_map, max_time,min_time);

		// dummy rotation key
		na->mRotationKeys = new aiQuatKey[1];
		na->mNumRotationKeys = 1;

		na->mRotationKeys[0].mTime = 0.;
		na->mRotationKeys[0].mValue = aiQuaternion();

		// dummy position key
		na->mPositionKeys = new aiVectorKey[1];
		na->mNumPositionKeys = 1;

		na->mPositionKeys[0].mTime = 0.;
		na->mPositionKeys[0].mValue = aiVector3D();

		return na.dismiss();
	}


	// ------------------------------------------------------------------------------------------------
	aiNodeAnim* GenerateTranslationNodeAnim(const std::string& name, 
		const Model& target, 
		const std::vector<const AnimationCurveNode*>& curves,
		const LayerMap& layer_map,
		double& max_time,
		double& min_time,
		bool inverse = false)
	{
		ScopeGuard<aiNodeAnim> na(new aiNodeAnim());
		na->mNodeName.Set(name);

		ConvertTranslationKeys(na, curves, layer_map, max_time,min_time);

		if (inverse) {
			for (unsigned int i = 0; i < na->mNumPositionKeys; ++i) {
				na->mPositionKeys[i].mValue *= -1.0f;
			}
		}

		// dummy scaling key
		na->mScalingKeys = new aiVectorKey[1];
		na->mNumScalingKeys = 1;

		na->mScalingKeys[0].mTime = 0.;
		na->mScalingKeys[0].mValue = aiVector3D(1.0f,1.0f,1.0f);

		// dummy rotation key
		na->mRotationKeys = new aiQuatKey[1];
		na->mNumRotationKeys = 1;

		na->mRotationKeys[0].mTime = 0.;
		na->mRotationKeys[0].mValue = aiQuaternion();

		return na.dismiss();
	}


	// ------------------------------------------------------------------------------------------------
	// generate node anim, extracting only Rotation, Scaling and Translation from the given chain
	aiNodeAnim* GenerateSimpleNodeAnim(const std::string& name, 
		const Model& target, 
		NodeMap::const_iterator chain[TransformationComp_MAXIMUM], 
		NodeMap::const_iterator iter_end,
		const LayerMap& layer_map,
		double& max_time,
		double& min_time)

	{
		ScopeGuard<aiNodeAnim> na(new aiNodeAnim());
		na->mNodeName.Set(name);

		const PropertyTable& props = target.Props();

		// if a particular transformation is not given, grab it from
		// the corresponding node to meet the semantics of aiNodeAnim,
		// which requires all of rotation, scaling and translation
		// to be set.
		if(chain[TransformationComp_Scaling] != iter_end) {
			ConvertScaleKeys(na, (*chain[TransformationComp_Scaling]).second, 
				layer_map, 
				max_time, 
				min_time);
		}
		else {
			na->mScalingKeys = new aiVectorKey[1];
			na->mNumScalingKeys = 1;

			na->mScalingKeys[0].mTime = 0.;
			na->mScalingKeys[0].mValue = PropertyGet(props,"Lcl Scaling",
				aiVector3D(1.f,1.f,1.f));
		}

		if(chain[TransformationComp_Rotation] != iter_end) {
			ConvertRotationKeys(na, (*chain[TransformationComp_Rotation]).second, 
				layer_map, 
				max_time,
				min_time);
		}
		else {
			na->mRotationKeys = new aiQuatKey[1];
			na->mNumRotationKeys = 1;

			na->mRotationKeys[0].mTime = 0.;
			na->mRotationKeys[0].mValue = EulerToQuaternion(
				PropertyGet(props,"Lcl Rotation",aiVector3D(0.f,0.f,0.f))
				);
		}

		if(chain[TransformationComp_Translation] != iter_end) {
			ConvertTranslationKeys(na, (*chain[TransformationComp_Translation]).second, 
				layer_map, 
				max_time, 
				min_time);
		}
		else {
			na->mPositionKeys = new aiVectorKey[1];
			na->mNumPositionKeys = 1;

			na->mPositionKeys[0].mTime = 0.;
			na->mPositionKeys[0].mValue = PropertyGet(props,"Lcl Translation",
				aiVector3D(0.f,0.f,0.f));
		}

		return na.dismiss();
	}



	// key (time), value, mapto (component index)
	typedef boost::tuple< const KeyTimeList*, const KeyValueList*, unsigned int > KeyFrameList;
	typedef std::vector<KeyFrameList> KeyFrameListList;

	

	// ------------------------------------------------------------------------------------------------
	KeyFrameListList GetKeyframeList(const std::vector<const AnimationCurveNode*>& nodes)
	{
		KeyFrameListList inputs;
		inputs.reserve(nodes.size()*3);

		BOOST_FOREACH(const AnimationCurveNode* node, nodes) {
			ai_assert(node);

			const AnimationCurveMap& curves = node->Curves();
			BOOST_FOREACH(const AnimationCurveMap::value_type& kv, curves) {

				unsigned int mapto;
				if (kv.first == "d|X") {
					mapto = 0;
				}
				else if (kv.first == "d|Y") {
					mapto = 1;
				}
				else if (kv.first == "d|Z") {
					mapto = 2;
				}
				else {
					FBXImporter::LogWarn("ignoring scale animation curve, did not recognize target component");
					continue;
				}

				const AnimationCurve* const curve = kv.second;
				ai_assert(curve->GetKeys().size() == curve->GetValues().size() && curve->GetKeys().size());

				inputs.push_back(boost::make_tuple(&curve->GetKeys(), &curve->GetValues(), mapto));
			}
		}
		return inputs; // pray for NRVO :-)
	}


	// ------------------------------------------------------------------------------------------------
	KeyTimeList GetKeyTimeList(const KeyFrameListList& inputs)
	{
		ai_assert(inputs.size());

		// reserve some space upfront - it is likely that the keyframe lists
		// have matching time values, so max(of all keyframe lists) should 
		// be a good estimate.
		KeyTimeList keys;
		
		size_t estimate = 0;
		BOOST_FOREACH(const KeyFrameList& kfl, inputs) {
			estimate = std::max(estimate, kfl.get<0>()->size());
		}

		keys.reserve(estimate);

		std::vector<unsigned int> next_pos;
		next_pos.resize(inputs.size(),0);

		const size_t count = inputs.size();
		while(true) {

			uint64_t min_tick = std::numeric_limits<uint64_t>::max();
			for (size_t i = 0; i < count; ++i) {
				const KeyFrameList& kfl = inputs[i];

				if (kfl.get<0>()->size() > next_pos[i] && kfl.get<0>()->at(next_pos[i]) < min_tick) {
					min_tick = kfl.get<0>()->at(next_pos[i]);
				}
			}

			if (min_tick == std::numeric_limits<uint64_t>::max()) {
				break;
			}
			keys.push_back(min_tick);

			for (size_t i = 0; i < count; ++i) {
				const KeyFrameList& kfl = inputs[i];


				while(kfl.get<0>()->size() > next_pos[i] && kfl.get<0>()->at(next_pos[i]) == min_tick) {
					++next_pos[i];
				}
			}
		}	

		return keys;
	}


	// ------------------------------------------------------------------------------------------------
	void InterpolateKeys(aiVectorKey* valOut,const KeyTimeList& keys, const KeyFrameListList& inputs, const bool geom, 
		double& maxTime,
		double& minTime)

	{
		ai_assert(keys.size());
		ai_assert(valOut);

		std::vector<unsigned int> next_pos;
		const size_t count = inputs.size();

		next_pos.resize(inputs.size(),0);

		BOOST_FOREACH(KeyTimeList::value_type time, keys) {
			float result[3] = {0.0f, 0.0f, 0.0f};
			if(geom) {
				result[0] = result[1] = result[2] = 1.0f;
			}

			for (size_t i = 0; i < count; ++i) {
				const KeyFrameList& kfl = inputs[i];

				const size_t ksize = kfl.get<0>()->size();
				if (ksize > next_pos[i] && kfl.get<0>()->at(next_pos[i]) == time) {
					++next_pos[i]; 
				}

				const size_t id0 = next_pos[i]>0 ? next_pos[i]-1 : 0;
				const size_t id1 = next_pos[i]==ksize ? ksize-1 : next_pos[i];

				// use lerp for interpolation
				const KeyValueList::value_type valueA = kfl.get<1>()->at(id0);
				const KeyValueList::value_type valueB = kfl.get<1>()->at(id1);

				const KeyTimeList::value_type timeA = kfl.get<0>()->at(id0);
				const KeyTimeList::value_type timeB = kfl.get<0>()->at(id1);

				// do the actual interpolation in double-precision arithmetics
				// because it is a bit sensitive to rounding errors.
				const double factor = timeB == timeA ? 0. : static_cast<double>((time - timeA) / (timeB - timeA));
				const float interpValue = static_cast<float>(valueA + (valueB - valueA) * factor);

				if(geom) {
					result[kfl.get<2>()] *= interpValue;
				}
				else {
					result[kfl.get<2>()] += interpValue;
				}
			}

			// magic value to convert fbx times to milliseconds
			valOut->mTime = static_cast<double>(time) / 46186158;

			minTime = std::min(minTime, valOut->mTime);
			maxTime = std::max(maxTime, valOut->mTime);

			valOut->mValue.x = result[0];
			valOut->mValue.y = result[1];
			valOut->mValue.z = result[2];
			
			++valOut;
		}
	}


	// ------------------------------------------------------------------------------------------------
	void InterpolateKeys(aiQuatKey* valOut,const KeyTimeList& keys, const KeyFrameListList& inputs, const bool geom,
		double& maxTime,
		double& minTime)
	{
		ai_assert(keys.size());
		ai_assert(valOut);

		boost::scoped_array<aiVectorKey> temp(new aiVectorKey[keys.size()]);
		InterpolateKeys(temp.get(),keys,inputs,geom,maxTime, minTime);

		for (size_t i = 0, c = keys.size(); i < c; ++i) {

			valOut[i].mTime = temp[i].mTime;
			valOut[i].mValue = EulerToQuaternion(temp[i].mValue); 
		}
	}


	// ------------------------------------------------------------------------------------------------
	// euler xyz -> quat
	aiQuaternion EulerToQuaternion(const aiVector3D& rot) 
	{
		aiMatrix4x4 m, mtemp;
		if(fabs(rot.x) > 1e-6f) {
			m *= aiMatrix4x4::RotationX(rot.x,mtemp);
		}
		if(fabs(rot.y) > 1e-6f) {
			m *= aiMatrix4x4::RotationY(rot.y,mtemp);
		}
		if(fabs(rot.z) > 1e-6f) {
			m *= aiMatrix4x4::RotationZ(rot.z,mtemp);
		}

		return aiQuaternion(aiMatrix3x3(m));
	}


	// ------------------------------------------------------------------------------------------------
	void ConvertScaleKeys(aiNodeAnim* na, const std::vector<const AnimationCurveNode*>& nodes, const LayerMap& layers,
		double& maxTime,
		double& minTime)
	{
		ai_assert(nodes.size());

		// XXX for now, assume scale should be blended geometrically (i.e. two
		// layers should be multiplied with each other). There is a FBX 
		// property in the layer to specify the behaviour, though.

		const KeyFrameListList& inputs = GetKeyframeList(nodes);
		const KeyTimeList& keys = GetKeyTimeList(inputs);

		na->mNumScalingKeys = static_cast<unsigned int>(keys.size());
		na->mScalingKeys = new aiVectorKey[keys.size()];
		InterpolateKeys(na->mScalingKeys, keys, inputs, true, maxTime, minTime);
	}


	// ------------------------------------------------------------------------------------------------
	void ConvertTranslationKeys(aiNodeAnim* na, const std::vector<const AnimationCurveNode*>& nodes, const LayerMap& layers,
		double& maxTime,
		double& minTime)
	{
		ai_assert(nodes.size());

		// XXX see notes in ConvertScaleKeys()
		const KeyFrameListList& inputs = GetKeyframeList(nodes);
		const KeyTimeList& keys = GetKeyTimeList(inputs);

		na->mNumPositionKeys = static_cast<unsigned int>(keys.size());
		na->mPositionKeys = new aiVectorKey[keys.size()];
		InterpolateKeys(na->mPositionKeys, keys, inputs, false, maxTime, minTime);
	}


	// ------------------------------------------------------------------------------------------------
	void ConvertRotationKeys(aiNodeAnim* na, const std::vector<const AnimationCurveNode*>& nodes, const LayerMap& layers, 
		double& maxTime,
		double& minTime)
	{
		ai_assert(nodes.size());

		// XXX see notes in ConvertScaleKeys()
		const std::vector< KeyFrameList >& inputs = GetKeyframeList(nodes);
		const KeyTimeList& keys = GetKeyTimeList(inputs);

		na->mNumRotationKeys = static_cast<unsigned int>(keys.size());
		na->mRotationKeys = new aiQuatKey[keys.size()];
		InterpolateKeys(na->mRotationKeys, keys, inputs, false, maxTime, minTime);
	}


	// ------------------------------------------------------------------------------------------------
	// copy generated meshes, animations, lights, cameras and textures to the output scene
	void TransferDataToScene()
	{
		ai_assert(!out->mMeshes && !out->mNumMeshes);

		// note: the trailing () ensures initialization with NULL - not
		// many C++ users seem to know this, so pointing it out to avoid
		// confusion why this code works.
		out->mMeshes = new aiMesh*[meshes.size()]();
		out->mNumMeshes = static_cast<unsigned int>(meshes.size());

		std::swap_ranges(meshes.begin(),meshes.end(),out->mMeshes);


		if(materials.size()) {
			out->mMaterials = new aiMaterial*[materials.size()]();
			out->mNumMaterials = static_cast<unsigned int>(materials.size());

			std::swap_ranges(materials.begin(),materials.end(),out->mMaterials);
		}

		if(animations.size()) {
			out->mAnimations = new aiAnimation*[animations.size()]();
			out->mNumAnimations = static_cast<unsigned int>(animations.size());

			std::swap_ranges(animations.begin(),animations.end(),out->mAnimations);
		}
	}


private:

	// 0: not assigned yet, others: index is value - 1
	unsigned int defaultMaterialIndex;

	std::vector<aiMesh*> meshes;
	std::vector<aiMaterial*> materials;
	std::vector<aiAnimation*> animations;

	typedef std::map<const Material*, unsigned int> MaterialMap;
	MaterialMap materials_converted;

	typedef std::map<const Geometry*, std::vector<unsigned int> > MeshMap;
	MeshMap meshes_converted;

	// fixed node name -> which trafo chain components have animations?
	typedef std::map<std::string, unsigned int> NodeAnimBitMap;
	NodeAnimBitMap node_anim_chain_bits;

	// name -> has had its prefix_stripped?
	typedef std::map<std::string, bool> NodeNameMap;
	NodeNameMap node_names;


	aiScene* const out;
	const FBX::Document& doc;
};

//} // !anon

// ------------------------------------------------------------------------------------------------
void ConvertToAssimpScene(aiScene* out, const Document& doc)
{
	Converter converter(out,doc);
}

} // !FBX
} // !Assimp

#endif