assimp/code/ColladaLoader.cpp

/*
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Open Asset Import Library (ASSIMP)
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/** @file Implementation of the Collada loader */

#include "AssimpPCH.h"
#ifndef ASSIMP_BUILD_NO_DAE_IMPORTER

#include "../include/aiAnim.h"
#include "ColladaLoader.h"
#include "ColladaParser.h"

#include "fast_atof.h"
#include "ParsingUtils.h"
#include "SkeletonMeshBuilder.h"

#include "time.h"

using namespace Assimp;

// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
ColladaLoader::ColladaLoader()
{}

// ------------------------------------------------------------------------------------------------
// Destructor, private as well
ColladaLoader::~ColladaLoader()
{}

// ------------------------------------------------------------------------------------------------
// Returns whether the class can handle the format of the given file. 
bool ColladaLoader::CanRead( const std::string& pFile, IOSystem* pIOHandler, bool checkSig) const
{
	// check file extension 
	std::string extension = GetExtension(pFile);
	
	if( extension == "dae")
		return true;

	// XML - too generic, we need to open the file and search for typical keywords
	if( extension == "xml" || !extension.length() || checkSig)	{
		/*  If CanRead() is called in order to check whether we
		 *  support a specific file extension in general pIOHandler
		 *  might be NULL and it's our duty to return true here.
		 */
		if (!pIOHandler)return true;
		const char* tokens[] = {"collada"};
		return SearchFileHeaderForToken(pIOHandler,pFile,tokens,1);
	}
	return false;
}

// ------------------------------------------------------------------------------------------------
// Get file extension list
void ColladaLoader::GetExtensionList( std::set<std::string>& extensions )
{
	extensions.insert("dae");
}

// ------------------------------------------------------------------------------------------------
// Imports the given file into the given scene structure. 
void ColladaLoader::InternReadFile( const std::string& pFile, aiScene* pScene, IOSystem* pIOHandler)
{
	mFileName = pFile;

	// clean all member arrays - just for safety, it should work even if we did not
	mMeshIndexByID.clear();
	mMaterialIndexByName.clear();
	mMeshes.clear();
	newMats.clear();
	mLights.clear();
	mCameras.clear();
	mTextures.clear();

	// parse the input file
	ColladaParser parser( pIOHandler, pFile);

	if( !parser.mRootNode)
		throw DeadlyImportError( "Collada: File came out empty. Something is wrong here.");

	// reserve some storage to avoid unnecessary reallocs
	newMats.reserve(parser.mMaterialLibrary.size()*2);
	mMeshes.reserve(parser.mMeshLibrary.size()*2);

	mCameras.reserve(parser.mCameraLibrary.size());
	mLights.reserve(parser.mLightLibrary.size());

	// create the materials first, for the meshes to find
	BuildMaterials( parser, pScene);

	// build the node hierarchy from it
	pScene->mRootNode = BuildHierarchy( parser, parser.mRootNode);

	// ... then fill the materials with the now adjusted settings
	FillMaterials(parser, pScene);

	// Convert to Y_UP, if different orientation
	if( parser.mUpDirection == ColladaParser::UP_X)
		pScene->mRootNode->mTransformation *= aiMatrix4x4( 
			 0, -1,  0,  0, 
			 1,  0,  0,  0,
			 0,  0,  1,  0,
			 0,  0,  0,  1);
	else if( parser.mUpDirection == ColladaParser::UP_Z)
		pScene->mRootNode->mTransformation *= aiMatrix4x4( 
			 1,  0,  0,  0, 
			 0,  0,  1,  0,
			 0, -1,  0,  0,
			 0,  0,  0,  1);

	// store all meshes
	StoreSceneMeshes( pScene);

	// store all materials
	StoreSceneMaterials( pScene);

	// store all lights
	StoreSceneLights( pScene);

	// store all cameras
	StoreSceneCameras( pScene);

	// store all animations
	StoreAnimations( pScene, parser);


	// If no meshes have been loaded, it's probably just an animated skeleton.
	if (!pScene->mNumMeshes) {
	
		SkeletonMeshBuilder hero(pScene);
		pScene->mFlags |= AI_SCENE_FLAGS_INCOMPLETE;
	}
}

// ------------------------------------------------------------------------------------------------
// Recursively constructs a scene node for the given parser node and returns it.
aiNode* ColladaLoader::BuildHierarchy( const ColladaParser& pParser, const Collada::Node* pNode)
{
	// create a node for it
	aiNode* node = new aiNode();

	// find a name for the new node. It's more complicated than you might think
	node->mName.Set( FindNameForNode( pNode));

	// calculate the transformation matrix for it
	node->mTransformation = pParser.CalculateResultTransform( pNode->mTransforms);

	// now resolve node instances
	std::vector<const Collada::Node*> instances;
	ResolveNodeInstances(pParser,pNode,instances);

	// add children. first the *real* ones
	node->mNumChildren = pNode->mChildren.size()+instances.size();
	node->mChildren = new aiNode*[node->mNumChildren];

	for( size_t a = 0; a < pNode->mChildren.size(); a++)
	{
		node->mChildren[a] = BuildHierarchy( pParser, pNode->mChildren[a]);
		node->mChildren[a]->mParent = node;
	}

	// ... and finally the resolved node instances
	for( size_t a = 0; a < instances.size(); a++)
	{
		node->mChildren[pNode->mChildren.size() + a] = BuildHierarchy( pParser, instances[a]);
		node->mChildren[pNode->mChildren.size() + a]->mParent = node;
	}

	// construct meshes
	BuildMeshesForNode( pParser, pNode, node);

	// construct cameras
	BuildCamerasForNode(pParser, pNode, node);

	// construct lights
	BuildLightsForNode(pParser, pNode, node);
	return node;
}

// ------------------------------------------------------------------------------------------------
// Resolve node instances
void ColladaLoader::ResolveNodeInstances( const ColladaParser& pParser, const Collada::Node* pNode,
	std::vector<const Collada::Node*>& resolved)
{
	// reserve enough storage
	resolved.reserve(pNode->mNodeInstances.size());

	// ... and iterate through all nodes to be instanced as children of pNode
	for (std::vector<Collada::NodeInstance>::const_iterator it = pNode->mNodeInstances.begin(),
		 end = pNode->mNodeInstances.end(); it != end; ++it)
	{
		// find the corresponding node in the library
		const ColladaParser::NodeLibrary::const_iterator itt = pParser.mNodeLibrary.find((*it).mNode);
		Collada::Node* nd = itt == pParser.mNodeLibrary.end() ? NULL : (*itt).second;

		// FIX for http://sourceforge.net/tracker/?func=detail&aid=3054873&group_id=226462&atid=1067632
		// need to check for both name and ID to catch all. To avoid breaking valid files,
		// the workaround is only enabled when the first attempt to resolve the node has failed.
		if (!nd) {
			nd = const_cast<Collada::Node*>(FindNode(pParser.mRootNode,(*it).mNode));
		}
		if (!nd) 
			DefaultLogger::get()->error("Collada: Unable to resolve reference to instanced node " + (*it).mNode);
		
		else {
			//	attach this node to the list of children
			resolved.push_back(nd);
		}
	}
}

// ------------------------------------------------------------------------------------------------
// Resolve UV channels
void ColladaLoader::ApplyVertexToEffectSemanticMapping(Collada::Sampler& sampler,
	 const Collada::SemanticMappingTable& table)
{
	std::map<std::string, Collada::InputSemanticMapEntry>::const_iterator it = table.mMap.find(sampler.mUVChannel);
	if (it != table.mMap.end()) {
		if (it->second.mType != Collada::IT_Texcoord)
			DefaultLogger::get()->error("Collada: Unexpected effect input mapping");

		sampler.mUVId = it->second.mSet;
	}
}

// ------------------------------------------------------------------------------------------------
// Builds lights for the given node and references them
void ColladaLoader::BuildLightsForNode( const ColladaParser& pParser, const Collada::Node* pNode, aiNode* pTarget)
{
	BOOST_FOREACH( const Collada::LightInstance& lid, pNode->mLights)
	{
		// find the referred light
		ColladaParser::LightLibrary::const_iterator srcLightIt = pParser.mLightLibrary.find( lid.mLight);
		if( srcLightIt == pParser.mLightLibrary.end())
		{
			DefaultLogger::get()->warn("Collada: Unable to find light for ID \"" + lid.mLight + "\". Skipping.");
			continue;
		}
		const Collada::Light* srcLight = &srcLightIt->second;
		if (srcLight->mType == aiLightSource_AMBIENT) {
			DefaultLogger::get()->error("Collada: Skipping ambient light for the moment");
			continue;
		}
		
		// now fill our ai data structure
		aiLight* out = new aiLight();
		out->mName = pTarget->mName;
		out->mType = (aiLightSourceType)srcLight->mType;

		// collada lights point in -Z by default, rest is specified in node transform
		out->mDirection = aiVector3D(0.f,0.f,-1.f);

		out->mAttenuationConstant = srcLight->mAttConstant;
		out->mAttenuationLinear = srcLight->mAttLinear;
		out->mAttenuationQuadratic = srcLight->mAttQuadratic;

		// collada doesn't differenciate between these color types
		out->mColorDiffuse = out->mColorSpecular = out->mColorAmbient = srcLight->mColor*srcLight->mIntensity;

		// convert falloff angle and falloff exponent in our representation, if given
		if (out->mType == aiLightSource_SPOT) {
			
			out->mAngleInnerCone = AI_DEG_TO_RAD( srcLight->mFalloffAngle );

			// ... some extension magic. FUCKING COLLADA. 
			if (srcLight->mOuterAngle == 10e10f) 
			{
				// ... some deprecation magic. FUCKING FCOLLADA.
				if (srcLight->mPenumbraAngle == 10e10f) 
				{
					// Need to rely on falloff_exponent. I don't know how to interpret it, so I need to guess ....
					// epsilon chosen to be 0.1
					out->mAngleOuterCone = AI_DEG_TO_RAD (acos(pow(0.1f,1.f/srcLight->mFalloffExponent))+
						srcLight->mFalloffAngle);
				}
				else {
					out->mAngleOuterCone = out->mAngleInnerCone + AI_DEG_TO_RAD(  srcLight->mPenumbraAngle );
					if (out->mAngleOuterCone < out->mAngleInnerCone)
						std::swap(out->mAngleInnerCone,out->mAngleOuterCone);
				}
			}
			else out->mAngleOuterCone = AI_DEG_TO_RAD(  srcLight->mOuterAngle );
		}

		// add to light list
		mLights.push_back(out);
	}
}

// ------------------------------------------------------------------------------------------------
// Builds cameras for the given node and references them
void ColladaLoader::BuildCamerasForNode( const ColladaParser& pParser, const Collada::Node* pNode, aiNode* pTarget)
{
	BOOST_FOREACH( const Collada::CameraInstance& cid, pNode->mCameras)
	{
		// find the referred light
		ColladaParser::CameraLibrary::const_iterator srcCameraIt = pParser.mCameraLibrary.find( cid.mCamera);
		if( srcCameraIt == pParser.mCameraLibrary.end())
		{
			DefaultLogger::get()->warn("Collada: Unable to find camera for ID \"" + cid.mCamera + "\". Skipping.");
			continue;
		}
		const Collada::Camera* srcCamera = &srcCameraIt->second;

		// orthographic cameras not yet supported in Assimp
		if (srcCamera->mOrtho) {
			DefaultLogger::get()->warn("Collada: Orthographic cameras are not supported.");
		}

		// now fill our ai data structure
		aiCamera* out = new aiCamera();
		out->mName = pTarget->mName;

		// collada cameras point in -Z by default, rest is specified in node transform
		out->mLookAt = aiVector3D(0.f,0.f,-1.f);

		// near/far z is already ok
		out->mClipPlaneFar = srcCamera->mZFar;
		out->mClipPlaneNear = srcCamera->mZNear;

		// ... but for the rest some values are optional 
		// and we need to compute the others in any combination. FUCKING COLLADA.
		 if (srcCamera->mAspect != 10e10f)
			out->mAspect = srcCamera->mAspect;

		if (srcCamera->mHorFov != 10e10f) {
			out->mHorizontalFOV = srcCamera->mHorFov; 

			if (srcCamera->mVerFov != 10e10f && srcCamera->mAspect == 10e10f) {
				out->mAspect = tan(AI_DEG_TO_RAD(srcCamera->mHorFov)) /
                    tan(AI_DEG_TO_RAD(srcCamera->mVerFov));
			}
		}
		else if (srcCamera->mAspect != 10e10f && srcCamera->mVerFov != 10e10f)	{
			out->mHorizontalFOV = 2.0f * AI_RAD_TO_DEG(atan(srcCamera->mAspect *
                tan(AI_DEG_TO_RAD(srcCamera->mVerFov) * 0.5f)));
		}

		// Collada uses degrees, we use radians
		out->mHorizontalFOV = AI_DEG_TO_RAD(out->mHorizontalFOV);

		// add to camera list
		mCameras.push_back(out);
	}
}

// ------------------------------------------------------------------------------------------------
// Builds meshes for the given node and references them
void ColladaLoader::BuildMeshesForNode( const ColladaParser& pParser, const Collada::Node* pNode, aiNode* pTarget)
{
	// accumulated mesh references by this node
	std::vector<size_t> newMeshRefs;
	newMeshRefs.reserve(pNode->mMeshes.size());

	// add a mesh for each subgroup in each collada mesh
	BOOST_FOREACH( const Collada::MeshInstance& mid, pNode->mMeshes)
	{
		const Collada::Mesh* srcMesh = NULL;
		const Collada::Controller* srcController = NULL;

		// find the referred mesh
		ColladaParser::MeshLibrary::const_iterator srcMeshIt = pParser.mMeshLibrary.find( mid.mMeshOrController);
		if( srcMeshIt == pParser.mMeshLibrary.end())
		{
			// if not found in the mesh-library, it might also be a controller referring to a mesh
			ColladaParser::ControllerLibrary::const_iterator srcContrIt = pParser.mControllerLibrary.find( mid.mMeshOrController);
			if( srcContrIt != pParser.mControllerLibrary.end())
			{
				srcController = &srcContrIt->second;
				srcMeshIt = pParser.mMeshLibrary.find( srcController->mMeshId);
				if( srcMeshIt != pParser.mMeshLibrary.end())
					srcMesh = srcMeshIt->second;
			}

			if( !srcMesh)
			{
				DefaultLogger::get()->warn( boost::str( boost::format( "Collada: Unable to find geometry for ID \"%s\". Skipping.") % mid.mMeshOrController));
				continue;
			}
		} else
		{
			// ID found in the mesh library -> direct reference to an unskinned mesh
			srcMesh = srcMeshIt->second;
		}

		// build a mesh for each of its subgroups
		size_t vertexStart = 0, faceStart = 0;
		for( size_t sm = 0; sm < srcMesh->mSubMeshes.size(); ++sm)
		{
			const Collada::SubMesh& submesh = srcMesh->mSubMeshes[sm];
			if( submesh.mNumFaces == 0)
				continue;

			// find material assigned to this submesh
			std::string meshMaterial;
			std::map<std::string, Collada::SemanticMappingTable >::const_iterator meshMatIt = mid.mMaterials.find( submesh.mMaterial);

			const Collada::SemanticMappingTable* table = NULL;
			if( meshMatIt != mid.mMaterials.end())
			{
				table = &meshMatIt->second;
				meshMaterial = table->mMatName;
			}
			else 
			{
				DefaultLogger::get()->warn( boost::str( boost::format( "Collada: No material specified for subgroup \"%s\" in geometry \"%s\".") % submesh.mMaterial % mid.mMeshOrController));
				if( !mid.mMaterials.empty() )
					meshMaterial = mid.mMaterials.begin()->second.mMatName;
			}

			// OK ... here the *real* fun starts ... we have the vertex-input-to-effect-semantic-table
			// given. The only mapping stuff which we do actually support is the UV channel.
			std::map<std::string, size_t>::const_iterator matIt = mMaterialIndexByName.find( meshMaterial);
			unsigned int matIdx;
			if( matIt != mMaterialIndexByName.end())
				matIdx = matIt->second;
			else
				matIdx = 0;

			if (table && !table->mMap.empty() ) {
				std::pair<Collada::Effect*, aiMaterial*>&  mat = newMats[matIdx];

				// Iterate through all texture channels assigned to the effect and
				// check whether we have mapping information for it.
				ApplyVertexToEffectSemanticMapping(mat.first->mTexDiffuse,    *table);
				ApplyVertexToEffectSemanticMapping(mat.first->mTexAmbient,    *table);
				ApplyVertexToEffectSemanticMapping(mat.first->mTexSpecular,   *table);
				ApplyVertexToEffectSemanticMapping(mat.first->mTexEmissive,   *table);
				ApplyVertexToEffectSemanticMapping(mat.first->mTexTransparent,*table);
				ApplyVertexToEffectSemanticMapping(mat.first->mTexBump,       *table);
			}

			// built lookup index of the Mesh-Submesh-Material combination
			ColladaMeshIndex index( mid.mMeshOrController, sm, meshMaterial);

			// if we already have the mesh at the library, just add its index to the node's array
			std::map<ColladaMeshIndex, size_t>::const_iterator dstMeshIt = mMeshIndexByID.find( index);
			if( dstMeshIt != mMeshIndexByID.end())	{
				newMeshRefs.push_back( dstMeshIt->second);
			} 
			else
			{
				// else we have to add the mesh to the collection and store its newly assigned index at the node
				aiMesh* dstMesh = CreateMesh( pParser, srcMesh, submesh, srcController, vertexStart, faceStart);

				// store the mesh, and store its new index in the node
				newMeshRefs.push_back( mMeshes.size());
				mMeshIndexByID[index] = mMeshes.size();
				mMeshes.push_back( dstMesh);
				vertexStart += dstMesh->mNumVertices; faceStart += submesh.mNumFaces;

				// assign the material index
				dstMesh->mMaterialIndex = matIdx;
			}
		}
	}

	// now place all mesh references we gathered in the target node
	pTarget->mNumMeshes = newMeshRefs.size();
	if( newMeshRefs.size())
	{
		pTarget->mMeshes = new unsigned int[pTarget->mNumMeshes];
		std::copy( newMeshRefs.begin(), newMeshRefs.end(), pTarget->mMeshes);
	}
}

// ------------------------------------------------------------------------------------------------
// Creates a mesh for the given ColladaMesh face subset and returns the newly created mesh
aiMesh* ColladaLoader::CreateMesh( const ColladaParser& pParser, const Collada::Mesh* pSrcMesh, const Collada::SubMesh& pSubMesh, 
	const Collada::Controller* pSrcController, size_t pStartVertex, size_t pStartFace)
{
	aiMesh* dstMesh = new aiMesh;

	// count the vertices addressed by its faces
	const size_t numVertices = std::accumulate( pSrcMesh->mFaceSize.begin() + pStartFace,
		pSrcMesh->mFaceSize.begin() + pStartFace + pSubMesh.mNumFaces, 0);

	// copy positions
	dstMesh->mNumVertices = numVertices;
	dstMesh->mVertices = new aiVector3D[numVertices];
	std::copy( pSrcMesh->mPositions.begin() + pStartVertex, pSrcMesh->mPositions.begin() + 
		pStartVertex + numVertices, dstMesh->mVertices);

	// normals, if given. HACK: (thom) Due to the fucking Collada spec we never 
	// know if we have the same number of normals as there are positions. So we 
	// also ignore any vertex attribute if it has a different count
	if( pSrcMesh->mNormals.size() >= pStartVertex + numVertices)
	{
		dstMesh->mNormals = new aiVector3D[numVertices];
		std::copy( pSrcMesh->mNormals.begin() + pStartVertex, pSrcMesh->mNormals.begin() +
			pStartVertex + numVertices, dstMesh->mNormals);
	}

	// tangents, if given. 
	if( pSrcMesh->mTangents.size() >= pStartVertex + numVertices)
	{
		dstMesh->mTangents = new aiVector3D[numVertices];
		std::copy( pSrcMesh->mTangents.begin() + pStartVertex, pSrcMesh->mTangents.begin() + 
			pStartVertex + numVertices, dstMesh->mTangents);
	}

	// bitangents, if given. 
	if( pSrcMesh->mBitangents.size() >= pStartVertex + numVertices)
	{
		dstMesh->mBitangents = new aiVector3D[numVertices];
		std::copy( pSrcMesh->mBitangents.begin() + pStartVertex, pSrcMesh->mBitangents.begin() + 
			pStartVertex + numVertices, dstMesh->mBitangents);
	}

	// same for texturecoords, as many as we have
	// empty slots are not allowed, need to pack and adjust UV indexes accordingly
	for( size_t a = 0, real = 0; a < AI_MAX_NUMBER_OF_TEXTURECOORDS; a++)
	{
		if( pSrcMesh->mTexCoords[a].size() >= pStartVertex + numVertices)
		{
			dstMesh->mTextureCoords[real] = new aiVector3D[numVertices];
			for( size_t b = 0; b < numVertices; ++b)
				dstMesh->mTextureCoords[real][b] = pSrcMesh->mTexCoords[a][pStartVertex+b];
			
			dstMesh->mNumUVComponents[real] = pSrcMesh->mNumUVComponents[a];
			++real;
		}
	}

	// same for vertex colors, as many as we have. again the same packing to avoid empty slots
	for( size_t a = 0, real = 0; a < AI_MAX_NUMBER_OF_COLOR_SETS; a++)
	{
		if( pSrcMesh->mColors[a].size() >= pStartVertex + numVertices)
		{
			dstMesh->mColors[real] = new aiColor4D[numVertices];
			std::copy( pSrcMesh->mColors[a].begin() + pStartVertex, pSrcMesh->mColors[a].begin() + pStartVertex + numVertices,dstMesh->mColors[real]);
			++real;
		}
	}

	// create faces. Due to the fact that each face uses unique vertices, we can simply count up on each vertex
	size_t vertex = 0;
	dstMesh->mNumFaces = pSubMesh.mNumFaces;
	dstMesh->mFaces = new aiFace[dstMesh->mNumFaces];
	for( size_t a = 0; a < dstMesh->mNumFaces; ++a)
	{
		size_t s = pSrcMesh->mFaceSize[ pStartFace + a];
		aiFace& face = dstMesh->mFaces[a];
		face.mNumIndices = s;
		face.mIndices = new unsigned int[s];
		for( size_t b = 0; b < s; ++b)
			face.mIndices[b] = vertex++;
	}

	// create bones if given
	if( pSrcController)
	{
		// refuse if the vertex count does not match
//		if( pSrcController->mWeightCounts.size() != dstMesh->mNumVertices)
//			throw DeadlyImportError( "Joint Controller vertex count does not match mesh vertex count");

		// resolve references - joint names
		const Collada::Accessor& jointNamesAcc = pParser.ResolveLibraryReference( pParser.mAccessorLibrary, pSrcController->mJointNameSource);
		const Collada::Data& jointNames = pParser.ResolveLibraryReference( pParser.mDataLibrary, jointNamesAcc.mSource);
		// joint offset matrices
		const Collada::Accessor& jointMatrixAcc = pParser.ResolveLibraryReference( pParser.mAccessorLibrary, pSrcController->mJointOffsetMatrixSource);
		const Collada::Data& jointMatrices = pParser.ResolveLibraryReference( pParser.mDataLibrary, jointMatrixAcc.mSource);
		// joint vertex_weight name list - should refer to the same list as the joint names above. If not, report and reconsider
		const Collada::Accessor& weightNamesAcc = pParser.ResolveLibraryReference( pParser.mAccessorLibrary, pSrcController->mWeightInputJoints.mAccessor);
		if( &weightNamesAcc != &jointNamesAcc)
			throw DeadlyImportError( "Temporary implementational lazyness. If you read this, please report to the author.");
		// vertex weights
		const Collada::Accessor& weightsAcc = pParser.ResolveLibraryReference( pParser.mAccessorLibrary, pSrcController->mWeightInputWeights.mAccessor);
		const Collada::Data& weights = pParser.ResolveLibraryReference( pParser.mDataLibrary, weightsAcc.mSource);

		if( !jointNames.mIsStringArray || jointMatrices.mIsStringArray || weights.mIsStringArray)
			throw DeadlyImportError( "Data type mismatch while resolving mesh joints");
		// sanity check: we rely on the vertex weights always coming as pairs of BoneIndex-WeightIndex
		if( pSrcController->mWeightInputJoints.mOffset != 0 || pSrcController->mWeightInputWeights.mOffset != 1)
			throw DeadlyImportError( "Unsupported vertex_weight adresssing scheme. Fucking collada spec.");

		// create containers to collect the weights for each bone
		size_t numBones = jointNames.mStrings.size();
		std::vector<std::vector<aiVertexWeight> > dstBones( numBones);

		// build a temporary array of pointers to the start of each vertex's weights
		typedef std::vector< std::pair<size_t, size_t> > IndexPairVector;
		std::vector<IndexPairVector::const_iterator> weightStartPerVertex( pSrcController->mWeightCounts.size());
		IndexPairVector::const_iterator pit = pSrcController->mWeights.begin();
		for( size_t a = 0; a < pSrcController->mWeightCounts.size(); ++a)
		{
			weightStartPerVertex[a] = pit;
			pit += pSrcController->mWeightCounts[a];
		}

		// now for each vertex put the corresponding vertex weights into each bone's weight collection
		for( size_t a = pStartVertex; a < pStartVertex + numVertices; ++a)
		{
			// which position index was responsible for this vertex? that's also the index by which
			// the controller assigns the vertex weights
			size_t orgIndex = pSrcMesh->mFacePosIndices[a];
			// find the vertex weights for this vertex
			IndexPairVector::const_iterator iit = weightStartPerVertex[orgIndex];
			size_t pairCount = pSrcController->mWeightCounts[orgIndex];

			for( size_t b = 0; b < pairCount; ++b, ++iit)
			{
				size_t jointIndex = iit->first;
				size_t vertexIndex = iit->second;

				float weight = ReadFloat( weightsAcc, weights, vertexIndex, 0);

				// one day I gonna kill that XSI Collada exporter
				if( weight > 0.0f)
				{
					aiVertexWeight w;
					w.mVertexId = a - pStartVertex;
					w.mWeight = weight;
					dstBones[jointIndex].push_back( w);
				}
			}
		}

		// count the number of bones which influence vertices of the current submesh
		size_t numRemainingBones = 0;
		for( std::vector<std::vector<aiVertexWeight> >::const_iterator it = dstBones.begin(); it != dstBones.end(); ++it)
			if( it->size() > 0)
				numRemainingBones++;

		// create bone array and copy bone weights one by one
		dstMesh->mNumBones = numRemainingBones;
		dstMesh->mBones = new aiBone*[numRemainingBones];
		size_t boneCount = 0;
		for( size_t a = 0; a < numBones; ++a)
		{
			// omit bones without weights
			if( dstBones[a].size() == 0)
				continue;

			// create bone with its weights
			aiBone* bone = new aiBone;
			bone->mName = ReadString( jointNamesAcc, jointNames, a);
			bone->mOffsetMatrix.a1 = ReadFloat( jointMatrixAcc, jointMatrices, a, 0);
			bone->mOffsetMatrix.a2 = ReadFloat( jointMatrixAcc, jointMatrices, a, 1);
			bone->mOffsetMatrix.a3 = ReadFloat( jointMatrixAcc, jointMatrices, a, 2);
			bone->mOffsetMatrix.a4 = ReadFloat( jointMatrixAcc, jointMatrices, a, 3);
			bone->mOffsetMatrix.b1 = ReadFloat( jointMatrixAcc, jointMatrices, a, 4);
			bone->mOffsetMatrix.b2 = ReadFloat( jointMatrixAcc, jointMatrices, a, 5);
			bone->mOffsetMatrix.b3 = ReadFloat( jointMatrixAcc, jointMatrices, a, 6);
			bone->mOffsetMatrix.b4 = ReadFloat( jointMatrixAcc, jointMatrices, a, 7);
			bone->mOffsetMatrix.c1 = ReadFloat( jointMatrixAcc, jointMatrices, a, 8);
			bone->mOffsetMatrix.c2 = ReadFloat( jointMatrixAcc, jointMatrices, a, 9);
			bone->mOffsetMatrix.c3 = ReadFloat( jointMatrixAcc, jointMatrices, a, 10);
			bone->mOffsetMatrix.c4 = ReadFloat( jointMatrixAcc, jointMatrices, a, 11);
			bone->mNumWeights = dstBones[a].size();
			bone->mWeights = new aiVertexWeight[bone->mNumWeights];
			std::copy( dstBones[a].begin(), dstBones[a].end(), bone->mWeights);

			// apply bind shape matrix to offset matrix
			aiMatrix4x4 bindShapeMatrix;
			bindShapeMatrix.a1 = pSrcController->mBindShapeMatrix[0];
			bindShapeMatrix.a2 = pSrcController->mBindShapeMatrix[1];
			bindShapeMatrix.a3 = pSrcController->mBindShapeMatrix[2];
			bindShapeMatrix.a4 = pSrcController->mBindShapeMatrix[3];
			bindShapeMatrix.b1 = pSrcController->mBindShapeMatrix[4];
			bindShapeMatrix.b2 = pSrcController->mBindShapeMatrix[5];
			bindShapeMatrix.b3 = pSrcController->mBindShapeMatrix[6];
			bindShapeMatrix.b4 = pSrcController->mBindShapeMatrix[7];
			bindShapeMatrix.c1 = pSrcController->mBindShapeMatrix[8];
			bindShapeMatrix.c2 = pSrcController->mBindShapeMatrix[9];
			bindShapeMatrix.c3 = pSrcController->mBindShapeMatrix[10];
			bindShapeMatrix.c4 = pSrcController->mBindShapeMatrix[11];
			bindShapeMatrix.d1 = pSrcController->mBindShapeMatrix[12];
			bindShapeMatrix.d2 = pSrcController->mBindShapeMatrix[13];
			bindShapeMatrix.d3 = pSrcController->mBindShapeMatrix[14];
			bindShapeMatrix.d4 = pSrcController->mBindShapeMatrix[15];
			bone->mOffsetMatrix *= bindShapeMatrix;

			// HACK: (thom) Some exporters address the bone nodes by SID, others address them by ID or even name.
			// Therefore I added a little name replacement here: I search for the bone's node by either name, ID or SID,
			// and replace the bone's name by the node's name so that the user can use the standard
			// find-by-name method to associate nodes with bones.
			const Collada::Node* bnode = FindNode( pParser.mRootNode, bone->mName.data);
			if( !bnode)
				bnode = FindNodeBySID( pParser.mRootNode, bone->mName.data);

			// assign the name that we would have assigned for the source node
			if( bnode)
				bone->mName.Set( FindNameForNode( bnode));
			else
				DefaultLogger::get()->warn( boost::str( boost::format( "ColladaLoader::CreateMesh(): could not find corresponding node for joint \"%s\".") % bone->mName.data));

			// and insert bone
			dstMesh->mBones[boneCount++] = bone;
		}
	}

	return dstMesh;
}

// ------------------------------------------------------------------------------------------------
// Stores all meshes in the given scene
void ColladaLoader::StoreSceneMeshes( aiScene* pScene)
{
	pScene->mNumMeshes = mMeshes.size();
	if( mMeshes.size() > 0)
	{
		pScene->mMeshes = new aiMesh*[mMeshes.size()];
		std::copy( mMeshes.begin(), mMeshes.end(), pScene->mMeshes);
		mMeshes.clear();
	}
}

// ------------------------------------------------------------------------------------------------
// Stores all cameras in the given scene
void ColladaLoader::StoreSceneCameras( aiScene* pScene)
{
	pScene->mNumCameras = mCameras.size();
	if( mCameras.size() > 0)
	{
		pScene->mCameras = new aiCamera*[mCameras.size()];
		std::copy( mCameras.begin(), mCameras.end(), pScene->mCameras);
		mCameras.clear();
	}
}

// ------------------------------------------------------------------------------------------------
// Stores all lights in the given scene
void ColladaLoader::StoreSceneLights( aiScene* pScene)
{
	pScene->mNumLights = mLights.size();
	if( mLights.size() > 0)
	{
		pScene->mLights = new aiLight*[mLights.size()];
		std::copy( mLights.begin(), mLights.end(), pScene->mLights);
		mLights.clear();
	}
}

// ------------------------------------------------------------------------------------------------
// Stores all textures in the given scene
void ColladaLoader::StoreSceneTextures( aiScene* pScene)
{
	pScene->mNumTextures = mTextures.size();
	if( mTextures.size() > 0)
	{
		pScene->mTextures = new aiTexture*[mTextures.size()];
		std::copy( mTextures.begin(), mTextures.end(), pScene->mTextures);
		mTextures.clear();
	}
}

// ------------------------------------------------------------------------------------------------
// Stores all materials in the given scene
void ColladaLoader::StoreSceneMaterials( aiScene* pScene)
{
	pScene->mNumMaterials = newMats.size();

	if (newMats.size() > 0) {
		pScene->mMaterials = new aiMaterial*[newMats.size()];
		for (unsigned int i = 0; i < newMats.size();++i)
			pScene->mMaterials[i] = newMats[i].second;

		newMats.clear();
	}
}

// ------------------------------------------------------------------------------------------------
// Stores all animations 
void ColladaLoader::StoreAnimations( aiScene* pScene, const ColladaParser& pParser)
{
	// recursivly collect all animations from the collada scene
	StoreAnimations( pScene, pParser, &pParser.mAnims, "");

	// catch special case: many animations with the same length, each affecting only a single node.
	// we need to unite all those single-node-anims to a proper combined animation
	for( size_t a = 0; a < mAnims.size(); ++a)
	{
		aiAnimation* templateAnim = mAnims[a];
		if( templateAnim->mNumChannels == 1)
		{
			// search for other single-channel-anims with the same duration
			std::vector<size_t> collectedAnimIndices;
			for( size_t b = a+1; b < mAnims.size(); ++b)
			{
				aiAnimation* other = mAnims[b];
				if( other->mNumChannels == 1 && other->mDuration == templateAnim->mDuration && other->mTicksPerSecond == templateAnim->mTicksPerSecond )
					collectedAnimIndices.push_back( b);
			}

			// if there are other animations which fit the template anim, combine all channels into a single anim
			if( !collectedAnimIndices.empty() )
			{
				aiAnimation* combinedAnim = new aiAnimation();
				combinedAnim->mName = aiString( std::string( "combinedAnim_") + char( '0' + a));
				combinedAnim->mDuration = templateAnim->mDuration;
				combinedAnim->mTicksPerSecond = templateAnim->mTicksPerSecond;
				combinedAnim->mNumChannels = collectedAnimIndices.size() + 1;
				combinedAnim->mChannels = new aiNodeAnim*[combinedAnim->mNumChannels];
				// add the template anim as first channel by moving its aiNodeAnim to the combined animation
				combinedAnim->mChannels[0] = templateAnim->mChannels[0];
				templateAnim->mChannels[0] = NULL;
				delete templateAnim;
				// combined animation replaces template animation in the anim array
				mAnims[a] = combinedAnim;

				// move the memory of all other anims to the combined anim and erase them from the source anims
				for( size_t b = 0; b < collectedAnimIndices.size(); ++b)
				{
					aiAnimation* srcAnimation = mAnims[collectedAnimIndices[b]];
					combinedAnim->mChannels[1 + b] = srcAnimation->mChannels[0];
					srcAnimation->mChannels[0] = NULL;
					delete srcAnimation;
				}

				// in a second go, delete all the single-channel-anims that we've stripped from their channels
				// back to front to preserve indices - you know, removing an element from a vector moves all elements behind the removed one
				while( !collectedAnimIndices.empty() )
				{
					mAnims.erase( mAnims.begin() + collectedAnimIndices.back());
					collectedAnimIndices.pop_back();
				}
			}
		}
	}

	// now store all anims in the scene
	if( !mAnims.empty())
	{
		pScene->mNumAnimations = mAnims.size();
		pScene->mAnimations = new aiAnimation*[mAnims.size()];
		std::copy( mAnims.begin(), mAnims.end(), pScene->mAnimations);
	}
}

// ------------------------------------------------------------------------------------------------
// Constructs the animations for the given source anim 
void ColladaLoader::StoreAnimations( aiScene* pScene, const ColladaParser& pParser, const Collada::Animation* pSrcAnim, const std::string pPrefix)
{
	std::string animName = pPrefix.empty() ? pSrcAnim->mName : pPrefix + "_" + pSrcAnim->mName;

	// create nested animations, if given
	for( std::vector<Collada::Animation*>::const_iterator it = pSrcAnim->mSubAnims.begin(); it != pSrcAnim->mSubAnims.end(); ++it)
		StoreAnimations( pScene, pParser, *it, animName);

	// create animation channels, if any
	if( !pSrcAnim->mChannels.empty())
		CreateAnimation( pScene, pParser, pSrcAnim, animName);
}

// ------------------------------------------------------------------------------------------------
// Constructs the animation for the given source anim
void ColladaLoader::CreateAnimation( aiScene* pScene, const ColladaParser& pParser, const Collada::Animation* pSrcAnim, const std::string& pName)
{
	// collect a list of animatable nodes
	std::vector<const aiNode*> nodes;
	CollectNodes( pScene->mRootNode, nodes);

	std::vector<aiNodeAnim*> anims;
	for( std::vector<const aiNode*>::const_iterator nit = nodes.begin(); nit != nodes.end(); ++nit)
	{
		// find all the collada anim channels which refer to the current node
		std::vector<Collada::ChannelEntry> entries;
		std::string nodeName = (*nit)->mName.data;

		// find the collada node corresponding to the aiNode
		const Collada::Node* srcNode = FindNode( pParser.mRootNode, nodeName);
//		ai_assert( srcNode != NULL);
		if( !srcNode)
			continue;

		// now check all channels if they affect the current node
		for( std::vector<Collada::AnimationChannel>::const_iterator cit = pSrcAnim->mChannels.begin();
			cit != pSrcAnim->mChannels.end(); ++cit)
		{
			const Collada::AnimationChannel& srcChannel = *cit;
			Collada::ChannelEntry entry;

			// we except the animation target to be of type "nodeName/transformID.subElement". Ignore all others
			// find the slash that separates the node name - there should be only one
			std::string::size_type slashPos = srcChannel.mTarget.find( '/');
			if( slashPos == std::string::npos)
				continue;
			if( srcChannel.mTarget.find( '/', slashPos+1) != std::string::npos)
				continue;
			std::string targetID = srcChannel.mTarget.substr( 0, slashPos);
			if( targetID != srcNode->mID)
				continue;

			// find the dot that separates the transformID - there should be only one or zero
			std::string::size_type dotPos = srcChannel.mTarget.find( '.');
			if( dotPos != std::string::npos)
			{
				if( srcChannel.mTarget.find( '.', dotPos+1) != std::string::npos)
					continue;

				entry.mTransformId = srcChannel.mTarget.substr( slashPos+1, dotPos - slashPos - 1);

				std::string subElement = srcChannel.mTarget.substr( dotPos+1);
				if( subElement == "ANGLE")
					entry.mSubElement = 3; // last number in an Axis-Angle-Transform is the angle
				else if( subElement == "X")
					entry.mSubElement = 0;
				else if( subElement == "Y")
					entry.mSubElement = 1;
				else if( subElement == "Z")
					entry.mSubElement = 2;
				else 
					DefaultLogger::get()->warn( boost::str( boost::format( "Unknown anim subelement \"%s\". Ignoring") % subElement));
			} else
			{
				// no subelement following, transformId is remaining string
				entry.mTransformId = srcChannel.mTarget.substr( slashPos+1);
			}

			// determine which transform step is affected by this channel
			entry.mTransformIndex = SIZE_MAX;
			for( size_t a = 0; a < srcNode->mTransforms.size(); ++a)
				if( srcNode->mTransforms[a].mID == entry.mTransformId)
					entry.mTransformIndex = a;

			if( entry.mTransformIndex == SIZE_MAX) {
				continue;
			}

			entry.mChannel = &(*cit);
			entries.push_back( entry);
		}

		// if there's no channel affecting the current node, we skip it
		if( entries.empty())
			continue;

		// resolve the data pointers for all anim channels. Find the minimum time while we're at it
		float startTime = 1e20f, endTime = -1e20f;
		for( std::vector<Collada::ChannelEntry>::iterator it = entries.begin(); it != entries.end(); ++it)
		{
			Collada::ChannelEntry& e = *it;
			e.mTimeAccessor = &pParser.ResolveLibraryReference( pParser.mAccessorLibrary, e.mChannel->mSourceTimes);
			e.mTimeData = &pParser.ResolveLibraryReference( pParser.mDataLibrary, e.mTimeAccessor->mSource);
			e.mValueAccessor = &pParser.ResolveLibraryReference( pParser.mAccessorLibrary, e.mChannel->mSourceValues);
			e.mValueData = &pParser.ResolveLibraryReference( pParser.mDataLibrary, e.mValueAccessor->mSource);

			// time count and value count must match
			if( e.mTimeAccessor->mCount != e.mValueAccessor->mCount)
				throw DeadlyImportError( boost::str( boost::format( "Time count / value count mismatch in animation channel \"%s\".") % e.mChannel->mTarget));

			// find bounding times
			startTime = std::min( startTime, ReadFloat( *e.mTimeAccessor, *e.mTimeData, 0, 0));
			endTime = std::max( endTime, ReadFloat( *e.mTimeAccessor, *e.mTimeData, e.mTimeAccessor->mCount-1, 0));
		}

		// create a local transformation chain of the node's transforms
		std::vector<Collada::Transform> transforms = srcNode->mTransforms;

		// now for every unique point in time, find or interpolate the key values for that time
		// and apply them to the transform chain. Then the node's present transformation can be calculated.
		float time = startTime;
		std::vector<aiMatrix4x4> resultTrafos;
		while( 1)
		{
			for( std::vector<Collada::ChannelEntry>::iterator it = entries.begin(); it != entries.end(); ++it)
			{
				Collada::ChannelEntry& e = *it;

				// find the keyframe behind the current point in time
				size_t pos = 0;
				float postTime = 0.f;
				while( 1)
				{
					if( pos >= e.mTimeAccessor->mCount)
						break;
					postTime = ReadFloat( *e.mTimeAccessor, *e.mTimeData, pos, 0);
					if( postTime >= time)
						break;
					++pos;
				}

				pos = std::min( pos, e.mTimeAccessor->mCount-1);

				// read values from there
				float temp[16];
				for( size_t c = 0; c < e.mValueAccessor->mSize; ++c)
					temp[c] = ReadFloat( *e.mValueAccessor, *e.mValueData, pos, c);

				// if not exactly at the key time, interpolate with previous value set
				if( postTime > time && pos > 0)
				{
					float preTime = ReadFloat( *e.mTimeAccessor, *e.mTimeData, pos-1, 0);
					float factor = (time - postTime) / (preTime - postTime);

					for( size_t c = 0; c < e.mValueAccessor->mSize; ++c)
					{
						float v = ReadFloat( *e.mValueAccessor, *e.mValueData, pos-1, c);
						temp[c] += (v - temp[c]) * factor;
					}
				}

				// Apply values to current transformation
				std::copy( temp, temp + e.mValueAccessor->mSize, transforms[e.mTransformIndex].f + e.mSubElement);
			}

			// Calculate resulting transformation
			aiMatrix4x4 mat = pParser.CalculateResultTransform( transforms);

			// out of lazyness: we store the time in matrix.d4
			mat.d4 = time;
			resultTrafos.push_back( mat);

			// find next point in time to evaluate. That's the closest frame larger than the current in any channel
			float nextTime = 1e20f;
			for( std::vector<Collada::ChannelEntry>::iterator it = entries.begin(); it != entries.end(); ++it)
			{
				Collada::ChannelEntry& e = *it;

				// find the next time value larger than the current
				size_t pos = 0;
				while( pos < e.mTimeAccessor->mCount)
				{
					float t = ReadFloat( *e.mTimeAccessor, *e.mTimeData, pos, 0);
					if( t > time)
					{
						nextTime = std::min( nextTime, t);
						break;
					}
					++pos;
				}
			}

			// no more keys on any channel after the current time -> we're done
			if( nextTime > 1e19)
				break;

			// else construct next keyframe at this following time point
			time = nextTime;
		}

		// there should be some keyframes
		ai_assert( resultTrafos.size() > 0);

		// build an animation channel for the given node out of these trafo keys
		aiNodeAnim* dstAnim = new aiNodeAnim;
		dstAnim->mNodeName = nodeName;
		dstAnim->mNumPositionKeys = resultTrafos.size();
		dstAnim->mNumRotationKeys= resultTrafos.size();
		dstAnim->mNumScalingKeys = resultTrafos.size();
		dstAnim->mPositionKeys = new aiVectorKey[resultTrafos.size()];
		dstAnim->mRotationKeys = new aiQuatKey[resultTrafos.size()];
		dstAnim->mScalingKeys = new aiVectorKey[resultTrafos.size()];

		for( size_t a = 0; a < resultTrafos.size(); ++a)
		{
			const aiMatrix4x4& mat = resultTrafos[a];
			double time = double( mat.d4); // remember? time is stored in mat.d4

			dstAnim->mPositionKeys[a].mTime = time;
			dstAnim->mRotationKeys[a].mTime = time;
			dstAnim->mScalingKeys[a].mTime = time;
			mat.Decompose( dstAnim->mScalingKeys[a].mValue, dstAnim->mRotationKeys[a].mValue, dstAnim->mPositionKeys[a].mValue);
		}

		anims.push_back( dstAnim);
	}

	if( !anims.empty())
	{
		aiAnimation* anim = new aiAnimation;
		anim->mName.Set( pName);
		anim->mNumChannels = anims.size();
		anim->mChannels = new aiNodeAnim*[anims.size()];
		std::copy( anims.begin(), anims.end(), anim->mChannels);
		anim->mDuration = 0.0f;
		for( size_t a = 0; a < anims.size(); ++a)
		{
			anim->mDuration = std::max( anim->mDuration, anims[a]->mPositionKeys[anims[a]->mNumPositionKeys-1].mTime);
			anim->mDuration = std::max( anim->mDuration, anims[a]->mRotationKeys[anims[a]->mNumRotationKeys-1].mTime);
			anim->mDuration = std::max( anim->mDuration, anims[a]->mScalingKeys[anims[a]->mNumScalingKeys-1].mTime);
		}
		anim->mTicksPerSecond = 1;
		mAnims.push_back( anim);
	}
}

// ------------------------------------------------------------------------------------------------
// Add a texture to a material structure
void ColladaLoader::AddTexture ( Assimp::MaterialHelper& mat, const ColladaParser& pParser,
	const Collada::Effect& effect,
	const Collada::Sampler& sampler,
	aiTextureType type, unsigned int idx)
{
	// first of all, basic file name
	const aiString name = FindFilenameForEffectTexture( pParser, effect, sampler.mName );
	mat.AddProperty( &name, _AI_MATKEY_TEXTURE_BASE, type, idx );

	// mapping mode
	int map = aiTextureMapMode_Clamp;
	if (sampler.mWrapU)
		map = aiTextureMapMode_Wrap;
	if (sampler.mWrapU && sampler.mMirrorU)
		map = aiTextureMapMode_Mirror;

	mat.AddProperty( &map, 1, _AI_MATKEY_MAPPINGMODE_U_BASE, type, idx);

	map = aiTextureMapMode_Clamp;
	if (sampler.mWrapV)
		map = aiTextureMapMode_Wrap;
	if (sampler.mWrapV && sampler.mMirrorV)
		map = aiTextureMapMode_Mirror;

	mat.AddProperty( &map, 1, _AI_MATKEY_MAPPINGMODE_V_BASE, type, idx);

	// UV transformation
	mat.AddProperty(&sampler.mTransform, 1,
		_AI_MATKEY_UVTRANSFORM_BASE, type, idx);

	// Blend mode
	mat.AddProperty((int*)&sampler.mOp , 1,
		_AI_MATKEY_TEXBLEND_BASE, type, idx);

	// Blend factor
	mat.AddProperty((float*)&sampler.mWeighting , 1,
		_AI_MATKEY_TEXBLEND_BASE, type, idx);

	// UV source index ... if we didn't resolve the mapping, it is actually just 
	// a guess but it works in most cases. We search for the frst occurence of a
	// number in the channel name. We assume it is the zero-based index into the
	// UV channel array of all corresponding meshes. It could also be one-based
	// for some exporters, but we won't care of it unless someone complains about.
	if (sampler.mUVId != UINT_MAX)
		map = sampler.mUVId;
	else {
		map = -1;
		for (std::string::const_iterator it = sampler.mUVChannel.begin();it != sampler.mUVChannel.end(); ++it){
			if (IsNumeric(*it)) {
				map = strtoul10(&(*it));
				break;
			}
		}
		if (-1 == map) {
			DefaultLogger::get()->warn("Collada: unable to determine UV channel for texture");
			map = 0;
		}
	}
	mat.AddProperty(&map,1,_AI_MATKEY_UVWSRC_BASE,type,idx);
}

// ------------------------------------------------------------------------------------------------
// Fills materials from the collada material definitions
void ColladaLoader::FillMaterials( const ColladaParser& pParser, aiScene* /*pScene*/)
{
	for (std::vector<std::pair<Collada::Effect*, aiMaterial*> >::iterator it = newMats.begin(),
		end = newMats.end(); it != end; ++it)
	{
		MaterialHelper&  mat = (MaterialHelper&)*it->second; 
		Collada::Effect& effect = *it->first;

		// resolve shading mode
		int shadeMode;
		if (effect.mFaceted) /* fixme */
			shadeMode = aiShadingMode_Flat;
		else {
			switch( effect.mShadeType)
			{
			case Collada::Shade_Constant: 
				shadeMode = aiShadingMode_NoShading; 
				break;
			case Collada::Shade_Lambert:
				shadeMode = aiShadingMode_Gouraud; 
				break;
			case Collada::Shade_Blinn: 
				shadeMode = aiShadingMode_Blinn;
				break;
			case Collada::Shade_Phong: 
				shadeMode = aiShadingMode_Phong; 
				break;

			default:
				DefaultLogger::get()->warn("Collada: Unrecognized shading mode, using gouraud shading");
				shadeMode = aiShadingMode_Gouraud; 
				break;
			}
		}
		mat.AddProperty<int>( &shadeMode, 1, AI_MATKEY_SHADING_MODEL);

		// double-sided?
		shadeMode = effect.mDoubleSided;
		mat.AddProperty<int>( &shadeMode, 1, AI_MATKEY_TWOSIDED);

		// wireframe?
		shadeMode = effect.mWireframe;
		mat.AddProperty<int>( &shadeMode, 1, AI_MATKEY_ENABLE_WIREFRAME);

		// add material colors
		mat.AddProperty( &effect.mAmbient, 1,AI_MATKEY_COLOR_AMBIENT);
		mat.AddProperty( &effect.mDiffuse, 1, AI_MATKEY_COLOR_DIFFUSE);
		mat.AddProperty( &effect.mSpecular, 1,AI_MATKEY_COLOR_SPECULAR);
		mat.AddProperty( &effect.mEmissive, 1,	AI_MATKEY_COLOR_EMISSIVE);
		mat.AddProperty( &effect.mTransparent, 1, AI_MATKEY_COLOR_TRANSPARENT);
		mat.AddProperty( &effect.mReflective, 1, AI_MATKEY_COLOR_REFLECTIVE);

		// scalar properties
		mat.AddProperty( &effect.mShininess, 1, AI_MATKEY_SHININESS);
		mat.AddProperty( &effect.mReflectivity, 1, AI_MATKEY_REFLECTIVITY);
		mat.AddProperty( &effect.mRefractIndex, 1, AI_MATKEY_REFRACTI);

		// transparency, a very hard one. seemingly not all files are following the
		// specification here .. but we can trick.
		if (effect.mTransparency > 0.f && effect.mTransparency < 1.f) {
			effect.mTransparency = 1.f- effect.mTransparency;
			mat.AddProperty( &effect.mTransparency, 1, AI_MATKEY_OPACITY );
			mat.AddProperty( &effect.mTransparent, 1, AI_MATKEY_COLOR_TRANSPARENT );
		}

		// add textures, if given
		if( !effect.mTexAmbient.mName.empty()) 
			 /* It is merely a lightmap */
			AddTexture( mat, pParser, effect, effect.mTexAmbient, aiTextureType_LIGHTMAP);

		if( !effect.mTexEmissive.mName.empty())
			AddTexture( mat, pParser, effect, effect.mTexEmissive, aiTextureType_EMISSIVE);

		if( !effect.mTexSpecular.mName.empty())
			AddTexture( mat, pParser, effect, effect.mTexSpecular, aiTextureType_SPECULAR);

		if( !effect.mTexDiffuse.mName.empty())
			AddTexture( mat, pParser, effect, effect.mTexDiffuse, aiTextureType_DIFFUSE);

		if( !effect.mTexBump.mName.empty())
			AddTexture( mat, pParser, effect, effect.mTexBump, aiTextureType_HEIGHT);

		if( !effect.mTexTransparent.mName.empty())
			AddTexture( mat, pParser, effect, effect.mTexTransparent, aiTextureType_OPACITY);

		if( !effect.mTexReflective.mName.empty())
			AddTexture( mat, pParser, effect, effect.mTexReflective, aiTextureType_REFLECTION);
	}
}

// ------------------------------------------------------------------------------------------------
// Constructs materials from the collada material definitions
void ColladaLoader::BuildMaterials( const ColladaParser& pParser, aiScene* /*pScene*/)
{
	newMats.reserve(pParser.mMaterialLibrary.size());

	for( ColladaParser::MaterialLibrary::const_iterator matIt = pParser.mMaterialLibrary.begin(); matIt != pParser.mMaterialLibrary.end(); ++matIt)
	{
		const Collada::Material& material = matIt->second;
		// a material is only a reference to an effect
		ColladaParser::EffectLibrary::const_iterator effIt = pParser.mEffectLibrary.find( material.mEffect);
		if( effIt == pParser.mEffectLibrary.end())
			continue;
		const Collada::Effect& effect = effIt->second;

		// create material
		Assimp::MaterialHelper* mat = new Assimp::MaterialHelper;
		aiString name( matIt->first);
		mat->AddProperty(&name,AI_MATKEY_NAME);

		// store the material
		mMaterialIndexByName[matIt->first] = newMats.size();
		newMats.push_back( std::pair<Collada::Effect*, aiMaterial*>(const_cast<Collada::Effect*>(&effect),mat) );
	}
	// ScenePreprocessor generates a default material automatically if none is there.
	// All further code here in this loader works well without a valid material so
	// we can safely let it to ScenePreprocessor.
#if 0
	if( newMats.size() == 0)
	{
		Assimp::MaterialHelper* mat = new Assimp::MaterialHelper;
		aiString name( AI_DEFAULT_MATERIAL_NAME );
		mat->AddProperty( &name, AI_MATKEY_NAME);

		const int shadeMode = aiShadingMode_Phong;
		mat->AddProperty<int>( &shadeMode, 1, AI_MATKEY_SHADING_MODEL);
		aiColor4D colAmbient( 0.2f, 0.2f, 0.2f, 1.0f), colDiffuse( 0.8f, 0.8f, 0.8f, 1.0f), colSpecular( 0.5f, 0.5f, 0.5f, 0.5f);
		mat->AddProperty( &colAmbient, 1, AI_MATKEY_COLOR_AMBIENT);
		mat->AddProperty( &colDiffuse, 1, AI_MATKEY_COLOR_DIFFUSE);
		mat->AddProperty( &colSpecular, 1, AI_MATKEY_COLOR_SPECULAR);
		const float specExp = 5.0f;
		mat->AddProperty( &specExp, 1, AI_MATKEY_SHININESS);
	}
#endif
}

// ------------------------------------------------------------------------------------------------
// Resolves the texture name for the given effect texture entry
aiString ColladaLoader::FindFilenameForEffectTexture( const ColladaParser& pParser,
	const Collada::Effect& pEffect, const std::string& pName)
{
	// recurse through the param references until we end up at an image
	std::string name = pName;
	while( 1)
	{
		// the given string is a param entry. Find it
		Collada::Effect::ParamLibrary::const_iterator it = pEffect.mParams.find( name);
		// if not found, we're at the end of the recursion. The resulting string should be the image ID
		if( it == pEffect.mParams.end())
			break;

		// else recurse on
		name = it->second.mReference;
	}

	// find the image referred by this name in the image library of the scene
	ColladaParser::ImageLibrary::const_iterator imIt = pParser.mImageLibrary.find( name);
	if( imIt == pParser.mImageLibrary.end()) 
	{
		throw DeadlyImportError( boost::str( boost::format( 
			"Collada: Unable to resolve effect texture entry \"%s\", ended up at ID \"%s\".") % pName % name));
	}

	aiString result;

	// if this is an embedded texture image setup an aiTexture for it
	if (imIt->second.mFileName.empty()) 
	{
		if (imIt->second.mImageData.empty())  {
			throw DeadlyImportError("Collada: Invalid texture, no data or file reference given");
		}

		aiTexture* tex = new aiTexture();

		// setup format hint
		if (imIt->second.mEmbeddedFormat.length() > 3) {
			DefaultLogger::get()->warn("Collada: texture format hint is too long, truncating to 3 characters");
		}
		strncpy(tex->achFormatHint,imIt->second.mEmbeddedFormat.c_str(),3);

		// and copy texture data
		tex->mHeight = 0;
		tex->mWidth = imIt->second.mImageData.size();
		tex->pcData = (aiTexel*)new char[tex->mWidth];
		memcpy(tex->pcData,&imIt->second.mImageData[0],tex->mWidth);

		// setup texture reference string
		result.data[0] = '*';
		result.length = 1 + ASSIMP_itoa10(result.data+1,MAXLEN-1,mTextures.size());

		// and add this texture to the list
		mTextures.push_back(tex);
	}
	else 
	{
		result.Set( imIt->second.mFileName );
		ConvertPath(result);
	}
	return result;
}

// ------------------------------------------------------------------------------------------------
// Convert a path read from a collada file to the usual representation
void ColladaLoader::ConvertPath (aiString& ss)
{
	// TODO: collada spec, p 22. Handle URI correctly.
	// For the moment we're just stripping the file:// away to make it work.
	// Windoes doesn't seem to be able to find stuff like
	// 'file://..\LWO\LWO2\MappingModes\earthSpherical.jpg'
	if (0 == strncmp(ss.data,"file://",7)) 
	{
		ss.length -= 7;
		memmove(ss.data,ss.data+7,ss.length);
		ss.data[ss.length] = '\0';
	}
}

// ------------------------------------------------------------------------------------------------
// Reads a float value from an accessor and its data array.
float ColladaLoader::ReadFloat( const Collada::Accessor& pAccessor, const Collada::Data& pData, size_t pIndex, size_t pOffset) const
{
	// FIXME: (thom) Test for data type here in every access? For the moment, I leave this to the caller
	size_t pos = pAccessor.mStride * pIndex + pAccessor.mOffset + pOffset;
	ai_assert( pos < pData.mValues.size());
	return pData.mValues[pos];
}

// ------------------------------------------------------------------------------------------------
// Reads a string value from an accessor and its data array.
const std::string& ColladaLoader::ReadString( const Collada::Accessor& pAccessor, const Collada::Data& pData, size_t pIndex) const
{
	size_t pos = pAccessor.mStride * pIndex + pAccessor.mOffset;
	ai_assert( pos < pData.mStrings.size());
	return pData.mStrings[pos];
}

// ------------------------------------------------------------------------------------------------
// Collects all nodes into the given array
void ColladaLoader::CollectNodes( const aiNode* pNode, std::vector<const aiNode*>& poNodes) const
{
	poNodes.push_back( pNode);

	for( size_t a = 0; a < pNode->mNumChildren; ++a)
		CollectNodes( pNode->mChildren[a], poNodes);
}

// ------------------------------------------------------------------------------------------------
// Finds a node in the collada scene by the given name
const Collada::Node* ColladaLoader::FindNode( const Collada::Node* pNode, const std::string& pName) const
{
	if( pNode->mName == pName || pNode->mID == pName)
		return pNode;

	for( size_t a = 0; a < pNode->mChildren.size(); ++a)
	{
		const Collada::Node* node = FindNode( pNode->mChildren[a], pName);
		if( node)
			return node;
	}

	return NULL;
}

// ------------------------------------------------------------------------------------------------
// Finds a node in the collada scene by the given SID
const Collada::Node* ColladaLoader::FindNodeBySID( const Collada::Node* pNode, const std::string& pSID) const
{
  if( pNode->mSID == pSID)
    return pNode;

  for( size_t a = 0; a < pNode->mChildren.size(); ++a)
  {
    const Collada::Node* node = FindNodeBySID( pNode->mChildren[a], pSID);
    if( node)
      return node;
  }

  return NULL;
}

// ------------------------------------------------------------------------------------------------
// Finds a proper name for a node derived from the collada-node's properties
std::string ColladaLoader::FindNameForNode( const Collada::Node* pNode) const
{
	// now setup the name of the node. We take the name if not empty, otherwise the collada ID
	// FIX: Workaround for XSI calling the instanced visual scene 'untitled' by default.
	if (!pNode->mName.empty() && pNode->mName != "untitled")
		return pNode->mName;
	else if (!pNode->mID.empty())
		return pNode->mID;
	else if (!pNode->mSID.empty())
    return pNode->mSID;
  else
	{
		// No need to worry. Unnamed nodes are no problem at all, except
		// if cameras or lights need to be assigned to them.
    return boost::str( boost::format( "$ColladaAutoName$_%d") % clock());
	}
}

#endif // !! ASSIMP_BUILD_NO_DAE_IMPORTER