text: /*
  ---------------------------------------------------------------------------
  Open Asset Import Library (assimp)
  ---------------------------------------------------------------------------
  
  Copyright (c) 2006-2017, assimp team
  
  
  All rights reserved.
  
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  with or without modification, are permitted provided that the following
  conditions are met:
  
  * Redistributions of source code must retain the above
  copyright notice, this list of conditions and the
  following disclaimer.
  
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  copyright notice, this list of conditions and the
  following disclaimer in the documentation and/or other
  materials provided with the distribution.
  
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  contributors may be used to endorse or promote products
  derived from this software without specific prior
  written permission of the assimp team.
  
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  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  */
  
  /** @file Implementation of the Collada loader */
  
  
  #ifndef ASSIMP_BUILD_NO_COLLADA_IMPORTER
  
  #include "ColladaLoader.h"
  #include <assimp/anim.h>
  #include <assimp/scene.h>
  #include <assimp/DefaultLogger.hpp>
  #include <assimp/Importer.hpp>
  #include <assimp/importerdesc.h>
  
  #include "ColladaParser.h"
  #include "fast_atof.h"
  #include "ParsingUtils.h"
  #include "SkeletonMeshBuilder.h"
  #include "CreateAnimMesh.h"
  
  #include "time.h"
  #include "math.h"
  #include <algorithm>
  #include <numeric>
  #include <assimp/Defines.h>
  
  using namespace Assimp;
  using namespace Assimp::Formatter;
  
  static const aiImporterDesc desc = {
      "Collada Importer",
      "",
      "",
      "http://collada.org",
      aiImporterFlags_SupportTextFlavour,
      1,
      3,
      1,
      5,
      "dae"
  };
  
  // ------------------------------------------------------------------------------------------------
  // Constructor to be privately used by Importer
  ColladaLoader::ColladaLoader()
      : mFileName()
  	, mMeshIndexByID()
  	, mMaterialIndexByName()
  	, mMeshes()
  	, newMats()
  	, mCameras()
  	, mLights()
  	, mTextures()
  	, mAnims()
  	, noSkeletonMesh( false )
      , ignoreUpDirection(false)
      , mNodeNameCounter( 0 )
  {}
  
  // ------------------------------------------------------------------------------------------------
  // 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;
  }
  
  // ------------------------------------------------------------------------------------------------
  void ColladaLoader::SetupProperties(const Importer* pImp)
  {
      noSkeletonMesh = pImp->GetPropertyInteger(AI_CONFIG_IMPORT_NO_SKELETON_MESHES,0) != 0;
      ignoreUpDirection = pImp->GetPropertyInteger(AI_CONFIG_IMPORT_COLLADA_IGNORE_UP_DIRECTION,0) != 0;
  }
  
  // ------------------------------------------------------------------------------------------------
  // Get file extension list
  const aiImporterDesc* ColladaLoader::GetInfo () const
  {
      return &desc;
  }
  
  // ------------------------------------------------------------------------------------------------
  // 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();
      mTargetMeshes.clear();
      newMats.clear();
      mLights.clear();
      mCameras.clear();
      mTextures.clear();
      mAnims.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);
  
          // Apply unitsize scale calculation
          pScene->mRootNode->mTransformation *= aiMatrix4x4(parser.mUnitSize, 0,  0,  0,
                                                            0,  parser.mUnitSize,  0,  0,
                                                            0,  0,  parser.mUnitSize,  0,
                                                            0,  0,  0,  1);
          if( !ignoreUpDirection ) {
          // 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) {
  
          if (!noSkeletonMesh) {
              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 = static_cast<unsigned int>(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 (const auto &nodeInst: pNode->mNodeInstances)
      {
          // find the corresponding node in the library
          const ColladaParser::NodeLibrary::const_iterator itt = pParser.mNodeLibrary.find(nodeInst.mNode);
          const 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 = FindNode(pParser.mRootNode, nodeInst.mNode);
          }
          if (!nd)
              DefaultLogger::get()->error("Collada: Unable to resolve reference to instanced node " + nodeInst.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)
  {
      for( 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;
  
          // 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;
  
          out->mColorDiffuse = out->mColorSpecular = out->mColorAmbient = srcLight->mColor*srcLight->mIntensity;
          if (out->mType == aiLightSource_AMBIENT) {
              out->mColorDiffuse = out->mColorSpecular = aiColor3D(0, 0, 0);
              out->mColorAmbient = srcLight->mColor*srcLight->mIntensity;
          }
          else {
              // collada doesn't differentiate between these color types
              out->mColorDiffuse = out->mColorSpecular = srcLight->mColor*srcLight->mIntensity;
              out->mColorAmbient = aiColor3D(0, 0, 0);
          }
  
          // 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.
              if (srcLight->mOuterAngle >= ASSIMP_COLLADA_LIGHT_ANGLE_NOT_SET*(1-1e-6f))
              {
                  // ... some deprecation magic.
                  if (srcLight->mPenumbraAngle >= ASSIMP_COLLADA_LIGHT_ANGLE_NOT_SET*(1-1e-6f))
                  {
                      // 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 = std::acos(std::pow(0.1f,1.f/srcLight->mFalloffExponent))+
                              out->mAngleInnerCone;
                  }
                  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)
  {
      for( 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.
           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 = std::tan(AI_DEG_TO_RAD(srcCamera->mHorFov)) /
                      std::tan(AI_DEG_TO_RAD(srcCamera->mVerFov));
              }
          }
          else if (srcCamera->mAspect != 10e10f && srcCamera->mVerFov != 10e10f)  {
              out->mHorizontalFOV = 2.0f * AI_RAD_TO_DEG(std::atan(srcCamera->mAspect *
                  std::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
      for( 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( format() << "Collada: Unable to find geometry for ID \"" << mid.mMeshOrController << "\". Skipping." );
                  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( format() << "Collada: No material specified for subgroup <" << submesh.mMaterial << "> in geometry <" << 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 = static_cast<unsigned int>(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;
                  if(dstMesh->mName.length == 0)
                  {
                      dstMesh->mName = mid.mMeshOrController;
                  }
        }
          }
      }
  
      // now place all mesh references we gathered in the target node
      pTarget->mNumMeshes = static_cast<unsigned int>(newMeshRefs.size());
      if( newMeshRefs.size())
      {
          struct UIntTypeConverter
          {
              unsigned int operator()(const size_t& v) const
              {
                  return static_cast<unsigned int>(v);
              }
          };
  
          pTarget->mMeshes = new unsigned int[pTarget->mNumMeshes];
          std::transform( newMeshRefs.begin(), newMeshRefs.end(), pTarget->mMeshes, UIntTypeConverter());
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Find mesh from either meshes or morph target meshes
  aiMesh *ColladaLoader::findMesh(std::string meshid)
  {
      for (unsigned int i = 0; i < mMeshes.size(); i++)
          if (std::string(mMeshes[i]->mName.data) == meshid)
              return mMeshes[i];
  
      for (unsigned int i = 0; i < mTargetMeshes.size(); i++)
          if (std::string(mTargetMeshes[i]->mName.data) == meshid)
              return mTargetMeshes[i];
  
      return NULL;
  }
  
  // ------------------------------------------------------------------------------------------------
  // 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;
  
      dstMesh->mName = pSrcMesh->mName;
  
      // count the vertices addressed by its faces
      const size_t numVertices = std::accumulate( pSrcMesh->mFaceSize.begin() + pStartFace,
          pSrcMesh->mFaceSize.begin() + pStartFace + pSubMesh.mNumFaces, size_t(0));
  
      // copy positions
      dstMesh->mNumVertices = static_cast<unsigned int>(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 glorious 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 = static_cast<unsigned int>(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 = static_cast<unsigned int>(s);
          face.mIndices = new unsigned int[s];
          for( size_t b = 0; b < s; ++b)
              face.mIndices[b] = static_cast<unsigned int>(vertex++);
      }
  
      // create morph target meshes if any
      std::vector<aiMesh*> targetMeshes;
      std::vector<float> targetWeights;
      Collada::MorphMethod method = Collada::Normalized;
  
      for(std::map<std::string, Collada::Controller>::const_iterator it = pParser.mControllerLibrary.begin();
          it != pParser.mControllerLibrary.end(); it++)
      {
          const Collada::Controller &c = it->second;
          const Collada::Mesh* baseMesh = pParser.ResolveLibraryReference( pParser.mMeshLibrary, c.mMeshId);
  
          if (c.mType == Collada::Morph && baseMesh->mName == pSrcMesh->mName)
          {
              const Collada::Accessor& targetAccessor = pParser.ResolveLibraryReference( pParser.mAccessorLibrary, c.mMorphTarget);
              const Collada::Accessor& weightAccessor = pParser.ResolveLibraryReference( pParser.mAccessorLibrary, c.mMorphWeight);
              const Collada::Data& targetData = pParser.ResolveLibraryReference( pParser.mDataLibrary, targetAccessor.mSource);
              const Collada::Data& weightData = pParser.ResolveLibraryReference( pParser.mDataLibrary, weightAccessor.mSource);
  
              // take method
              method = c.mMethod;
  
              if (!targetData.mIsStringArray)
                  throw DeadlyImportError( "target data must contain id. ");
              if (weightData.mIsStringArray)
                  throw DeadlyImportError( "target weight data must not be textual ");
  
              for (unsigned int i = 0; i < targetData.mStrings.size(); ++i)
              {
                  const Collada::Mesh* targetMesh = pParser.ResolveLibraryReference(pParser.mMeshLibrary, targetData.mStrings.at(i));
  
                  aiMesh *aimesh = findMesh(targetMesh->mName);
                  if (!aimesh)
                  {
                      if (targetMesh->mSubMeshes.size() > 1)
                          throw DeadlyImportError( "Morhing target mesh must be a single");
                      aimesh = CreateMesh(pParser, targetMesh, targetMesh->mSubMeshes.at(0), NULL, 0, 0);
                      mTargetMeshes.push_back(aimesh);
                  }
                  targetMeshes.push_back(aimesh);
              }
              for (unsigned int i = 0; i < weightData.mValues.size(); ++i)
                  targetWeights.push_back(weightData.mValues.at(i));
          }
      }
      if (targetMeshes.size() > 0 && targetWeights.size() == targetMeshes.size())
      {
          std::vector<aiAnimMesh*> animMeshes;
          for (unsigned int i = 0; i < targetMeshes.size(); i++)
          {
              aiAnimMesh *animMesh = aiCreateAnimMesh(targetMeshes.at(i));
              animMesh->mWeight = targetWeights[i];
              animMeshes.push_back(animMesh);
          }
          dstMesh->mMethod = (method == Collada::Relative)
                                  ? aiMorphingMethod_MORPH_RELATIVE
                                  : aiMorphingMethod_MORPH_NORMALIZED;
          dstMesh->mAnimMeshes = new aiAnimMesh*[animMeshes.size()];
          dstMesh->mNumAnimMeshes = static_cast<unsigned int>(animMeshes.size());
          for (unsigned int i = 0; i < animMeshes.size(); i++)
              dstMesh->mAnimMeshes[i] = animMeshes.at(i);
      }
  
      // create bones if given
      if( pSrcController && pSrcController->mType == Collada::Skin)
      {
          // 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 laziness. 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 addressing scheme. ");
  
          // 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;
          weightStartPerVertex.resize(pSrcController->mWeightCounts.size(),pSrcController->mWeights.end());
  
          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;
  
                  ai_real weight = ReadFloat( weightsAcc, weights, vertexIndex, 0);
  
                  // one day I gonna kill that XSI Collada exporter
                  if( weight > 0.0f)
                  {
                      aiVertexWeight w;
                      w.mVertexId = static_cast<unsigned int>(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 = static_cast<unsigned int>(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 = static_cast<unsigned int>(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( format() << "ColladaLoader::CreateMesh(): could not find corresponding node for joint \"" << 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 = static_cast<unsigned int>(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 = static_cast<unsigned int>(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 = static_cast<unsigned int>(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 = static_cast<unsigned int>(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 = static_cast<unsigned int>(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 = static_cast<unsigned int>(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 = static_cast<unsigned int>(mAnims.size());
          pScene->mAnimations = new aiAnimation*[mAnims.size()];
          std::copy( mAnims.begin(), mAnims.end(), pScene->mAnimations);
      }
  
      mAnims.clear();
  }
  
  // ------------------------------------------------------------------------------------------------
  // 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);
  }
  
  struct MorphTimeValues
  {
      float mTime;
      struct key
      {
          float mWeight;
          unsigned int mValue;
      };
      std::vector<key> mKeys;
  };
  
  void insertMorphTimeValue(std::vector<MorphTimeValues> &values, float time, float weight, unsigned int value)
  {
      MorphTimeValues::key k;
      k.mValue = value;
      k.mWeight = weight;
      if (values.size() == 0 || time < values[0].mTime)
      {
          MorphTimeValues val;
          val.mTime = time;
          val.mKeys.push_back(k);
          values.insert(values.begin(), val);
          return;
      }
      if (time > values.back().mTime)
      {
          MorphTimeValues val;
          val.mTime = time;
          val.mKeys.push_back(k);
          values.insert(values.end(), val);
          return;
      }
      for (unsigned int i = 0; i < values.size(); i++)
      {
          if (std::abs(time - values[i].mTime) < 1e-6f)
          {
              values[i].mKeys.push_back(k);
              return;
          } else if (time > values[i].mTime && time < values[i+1].mTime)
          {
              MorphTimeValues val;
              val.mTime = time;
              val.mKeys.push_back(k);
              values.insert(values.begin() + i, val);
              return;
          }
      }
      // should not get here
  }
  
  float getWeightAtKey(const std::vector<MorphTimeValues> &values, int key, unsigned int value)
  {
      for (unsigned int i = 0; i < values[key].mKeys.size(); i++)
      {
          if (values[key].mKeys[i].mValue == value)
              return values[key].mKeys[i].mWeight;
      }
      // no value at key found, try to interpolate if present at other keys. if not, return zero
      // TODO: interpolation
      return 0.0f;
  }
  
  // ------------------------------------------------------------------------------------------------
  // 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;
      std::vector<aiMeshMorphAnim*> morphAnims;
  
      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 expect 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)
              {
                  std::string::size_type targetPos = srcChannel.mTarget.find(srcNode->mID);
                  if (targetPos == std::string::npos)
                      continue;
  
                  // not node transform, but something else. store as unknown animation channel for now
                  entry.mChannel = &(*cit);
                  entry.mTargetId = srcChannel.mTarget.substr(targetPos + pSrcAnim->mName.length(),
                                          srcChannel.mTarget.length() - targetPos - pSrcAnim->mName.length());
                  if (entry.mTargetId.front() == '-')
                      entry.mTargetId = entry.mTargetId.substr(1);
                  entries.push_back(entry);
                  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( format() << "Unknown anim subelement <" << subElement << ">. Ignoring" );
              } else
              {
                  // no subelement following, transformId is remaining string
                  entry.mTransformId = srcChannel.mTarget.substr( slashPos+1);
              }
  
              std::string::size_type bracketPos = srcChannel.mTarget.find('(');
              if (bracketPos != std::string::npos)
              {
                  entry.mTransformId = srcChannel.mTarget.substr(slashPos + 1, bracketPos - slashPos - 1);
                  std::string subElement = srcChannel.mTarget.substr(bracketPos);
  
                  if (subElement == "(0)(0)")
                      entry.mSubElement = 0;
                  else if (subElement == "(1)(0)")
                      entry.mSubElement = 1;
                  else if (subElement == "(2)(0)")
                      entry.mSubElement = 2;
                  else if (subElement == "(3)(0)")
                      entry.mSubElement = 3;
                  else if (subElement == "(0)(1)")
                      entry.mSubElement = 4;
                  else if (subElement == "(1)(1)")
                      entry.mSubElement = 5;
                  else if (subElement == "(2)(1)")
                      entry.mSubElement = 6;
                  else if (subElement == "(3)(1)")
                      entry.mSubElement = 7;
                  else if (subElement == "(0)(2)")
                      entry.mSubElement = 8;
                  else if (subElement == "(1)(2)")
                      entry.mSubElement = 9;
                  else if (subElement == "(2)(2)")
                      entry.mSubElement = 10;
                  else if (subElement == "(3)(2)")
                      entry.mSubElement = 11;
                  else if (subElement == "(0)(3)")
                      entry.mSubElement = 12;
                  else if (subElement == "(1)(3)")
                      entry.mSubElement = 13;
                  else if (subElement == "(2)(3)")
                      entry.mSubElement = 14;
                  else if (subElement == "(3)(3)")
                      entry.mSubElement = 15;
  
              }
  
              // 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)
              {
                  if (entry.mTransformId.find("morph-weights") != std::string::npos)
                  {
                      entry.mTargetId = entry.mTransformId;
                      entry.mTransformId = "";
                  } else
                      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
          ai_real startTime = ai_real( 1e20 ), endTime = ai_real( -1e20 );
          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( format() << "Time count / value count mismatch in animation channel \"" << e.mChannel->mTarget << "\"." );
  
        if( e.mTimeAccessor->mCount > 0 )
        {
                // 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));
        }
          }
  
      std::vector<aiMatrix4x4> resultTrafos;
      if( !entries.empty() && entries.front().mTimeAccessor->mCount > 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.
            ai_real time = startTime;
            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;
                    ai_real postTime = 0.0;
                    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
                    ai_real 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)
                    {
                        ai_real preTime = ReadFloat( *e.mTimeAccessor, *e.mTimeData, pos-1, 0);
                        ai_real factor = (time - postTime) / (preTime - postTime);
  
                        for( size_t c = 0; c < e.mValueAccessor->mSize; ++c)
                        {
                            ai_real 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 laziness: 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
                ai_real nextTime = ai_real( 1e20 );
                for( std::vector<Collada::ChannelEntry>::iterator it = entries.begin(); it != entries.end(); ++it)
                {
                    Collada::ChannelEntry& channelElement = *it;
  
                    // find the next time value larger than the current
                    size_t pos = 0;
                    while( pos < channelElement.mTimeAccessor->mCount)
                    {
                        const ai_real t = ReadFloat( *channelElement.mTimeAccessor, *channelElement.mTimeData, pos, 0);
                        if( t > time)
                        {
                            nextTime = std::min( nextTime, t);
                            break;
                        }
                        ++pos;
                    }
  
  				  // https://github.com/assimp/assimp/issues/458
  			  	  // Sub-sample axis-angle channels if the delta between two consecutive
                    // key-frame angles is >= 180 degrees.
  				  if (transforms[channelElement.mTransformIndex].mType == Collada::TF_ROTATE && channelElement.mSubElement == 3 && pos > 0 && pos < channelElement.mTimeAccessor->mCount) {
  					  const ai_real cur_key_angle = ReadFloat(*channelElement.mValueAccessor, *channelElement.mValueData, pos, 0);
                        const ai_real last_key_angle = ReadFloat(*channelElement.mValueAccessor, *channelElement.mValueData, pos - 1, 0);
                        const ai_real cur_key_time = ReadFloat(*channelElement.mTimeAccessor, *channelElement.mTimeData, pos, 0);
                        const ai_real last_key_time = ReadFloat(*channelElement.mTimeAccessor, *channelElement.mTimeData, pos - 1, 0);
                        const ai_real last_eval_angle = last_key_angle + (cur_key_angle - last_key_angle) * (time - last_key_time) / (cur_key_time - last_key_time);
                        const ai_real delta = std::abs(cur_key_angle - last_eval_angle);
  				      if (delta >= 180.0) {
  						const int subSampleCount = static_cast<int>(std::floor(delta / 90.0));
  						if (cur_key_time != time) {
  							const ai_real nextSampleTime = time + (cur_key_time - time) / subSampleCount;
  							nextTime = std::min(nextTime, nextSampleTime);
  						  }
  					  }
  				  }
                }
  
                // 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, but we aren't that fixated on valid input data
  //      ai_assert( resultTrafos.size() > 0);
  
          // build an animation channel for the given node out of these trafo keys
          if( !resultTrafos.empty() )
          {
                aiNodeAnim* dstAnim = new aiNodeAnim;
                dstAnim->mNodeName = nodeName;
                dstAnim->mNumPositionKeys = static_cast<unsigned int>(resultTrafos.size());
                dstAnim->mNumRotationKeys = static_cast<unsigned int>(resultTrafos.size());
                dstAnim->mNumScalingKeys = static_cast<unsigned int>(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)
                {
                    aiMatrix4x4 mat = resultTrafos[a];
                    double time = double( mat.d4); // remember? time is stored in mat.d4
                      mat.d4 = 1.0f;
  
                    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);
          } else
          {
            DefaultLogger::get()->warn( "Collada loader: found empty animation channel, ignored. Please check your exporter.");
          }
  
          if( !entries.empty() && entries.front().mTimeAccessor->mCount > 0 )
          {
              std::vector<Collada::ChannelEntry> morphChannels;
              for( std::vector<Collada::ChannelEntry>::iterator it = entries.begin(); it != entries.end(); ++it)
              {
                  Collada::ChannelEntry& e = *it;
  
                  // skip non-transform types
                  if (e.mTargetId.empty())
                      continue;
  
                  if (e.mTargetId.find("morph-weights") != std::string::npos)
                      morphChannels.push_back(e);
              }
              if (morphChannels.size() > 0)
              {
                  // either 1) morph weight animation count should contain morph target count channels
                  // or     2) one channel with morph target count arrays
                  // assume first
  
                  aiMeshMorphAnim *morphAnim = new aiMeshMorphAnim;
                  morphAnim->mName.Set(nodeName);
  
                  std::vector<MorphTimeValues> morphTimeValues;
  
                  int morphAnimChannelIndex = 0;
                  for( std::vector<Collada::ChannelEntry>::iterator it = morphChannels.begin(); it != morphChannels.end(); ++it)
                  {
                      Collada::ChannelEntry& e = *it;
                      std::string::size_type apos = e.mTargetId.find('(');
                      std::string::size_type bpos = e.mTargetId.find(')');
                      if (apos == std::string::npos || bpos == std::string::npos)
                          // unknown way to specify weight -> ignore this animation
                          continue;
  
                      // weight target can be in format Weight_M_N, Weight_N, WeightN, or some other way
                      // we ignore the name and just assume the channels are in the right order
                      for (unsigned int i = 0; i < e.mTimeData->mValues.size(); i++)
                          insertMorphTimeValue(morphTimeValues, e.mTimeData->mValues.at(i), e.mValueData->mValues.at(i), morphAnimChannelIndex);
  
                      ++morphAnimChannelIndex;
                  }
  
                  morphAnim->mNumKeys = static_cast<unsigned int>(morphTimeValues.size());
                  morphAnim->mKeys = new aiMeshMorphKey[morphAnim->mNumKeys];
                  for (unsigned int key = 0; key < morphAnim->mNumKeys; key++)
                  {
                      morphAnim->mKeys[key].mNumValuesAndWeights = static_cast<unsigned int>(morphChannels.size());
                      morphAnim->mKeys[key].mValues = new unsigned int [morphChannels.size()];
                      morphAnim->mKeys[key].mWeights = new double [morphChannels.size()];
  
                      morphAnim->mKeys[key].mTime = morphTimeValues[key].mTime;
                      for (unsigned int valueIndex = 0; valueIndex < morphChannels.size(); valueIndex++)
                      {
                          morphAnim->mKeys[key].mValues[valueIndex] = valueIndex;
                          morphAnim->mKeys[key].mWeights[valueIndex] = getWeightAtKey(morphTimeValues, key, valueIndex);
                      }
                  }
  
                  morphAnims.push_back(morphAnim);
              }
          }
      }
  
      if( !anims.empty() || !morphAnims.empty())
      {
          aiAnimation* anim = new aiAnimation;
          anim->mName.Set( pName);
          anim->mNumChannels = static_cast<unsigned int>(anims.size());
          if (anim->mNumChannels > 0)
          {
              anim->mChannels = new aiNodeAnim*[anims.size()];
              std::copy( anims.begin(), anims.end(), anim->mChannels);
          }
          anim->mNumMorphMeshChannels = static_cast<unsigned int>(morphAnims.size());
          if (anim->mNumMorphMeshChannels > 0)
          {
              anim->mMorphMeshChannels = new aiMeshMorphAnim*[anim->mNumMorphMeshChannels];
              std::copy( morphAnims.begin(), morphAnims.end(), anim->mMorphMeshChannels);
          }
          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);
          }
          for (size_t a = 0; a < morphAnims.size(); ++a)
          {
              anim->mDuration = std::max(anim->mDuration, morphAnims[a]->mKeys[morphAnims[a]->mNumKeys-1].mTime);
          }
          anim->mTicksPerSecond = 1;
          mAnims.push_back( anim);
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Add a texture to a material structure
  void ColladaLoader::AddTexture ( aiMaterial& 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((ai_real*)&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 occurrence 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 (auto &elem : newMats)
      {
          aiMaterial&  mat = (aiMaterial&)*elem.second;
          Collada::Effect& effect = *elem.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.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 (1.0 transparency => completely opaque)...
          // therefore, we let the opportunity for the user to manually invert
          // the transparency if necessary and we add preliminary support for RGB_ZERO mode
          if(effect.mTransparency >= 0.f && effect.mTransparency <= 1.f) {
              // handle RGB transparency completely, cf Collada specs 1.5.0 pages 249 and 304
              if(effect.mRGBTransparency) {
  				// use luminance as defined by ISO/CIE color standards (see ITU-R Recommendation BT.709-4)
                  effect.mTransparency *= (
                      0.212671f * effect.mTransparent.r +
                      0.715160f * effect.mTransparent.g +
                      0.072169f * effect.mTransparent.b
                  );
  
                  effect.mTransparent.a = 1.f;
  
                  mat.AddProperty( &effect.mTransparent, 1, AI_MATKEY_COLOR_TRANSPARENT );
              } else {
                  effect.mTransparency *=  effect.mTransparent.a;
              }
  
              if(effect.mInvertTransparency) {
                  effect.mTransparency = 1.f - effect.mTransparency;
              }
  
              // Is the material finally transparent ?
              if (effect.mHasTransparency || effect.mTransparency < 1.f) {
                  mat.AddProperty( &effect.mTransparency, 1, AI_MATKEY_OPACITY );
              }
          }
  
          // 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_NORMALS);
  
          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( 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::iterator effIt = pParser.mEffectLibrary.find( material.mEffect);
          if( effIt == pParser.mEffectLibrary.end())
              continue;
          Collada::Effect& effect = effIt->second;
  
          // create material
          aiMaterial* mat = new aiMaterial;
          aiString name( material.mName.empty() ? matIt->first : material.mName );
          mat->AddProperty(&name,AI_MATKEY_NAME);
  
          // store the material
          mMaterialIndexByName[matIt->first] = newMats.size();
          newMats.push_back( std::pair<Collada::Effect*, aiMaterial*>( &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)
      {
          aiMaterial* mat = new aiMaterial;
          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( 0.2, 0.2, 0.2, 1.0), colDiffuse( 0.8, 0.8, 0.8, 1.0), colSpecular( 0.5, 0.5, 0.5, 0.5);
          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 ai_real specExp = 5.0;
          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)
  {
      aiString result;
  
      // 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())
      {
          //missing texture should not stop the conversion
          //throw DeadlyImportError( format() <<
          //    "Collada: Unable to resolve effect texture entry \"" << pName << "\", ended up at ID \"" << name << "\"." );
  
          DefaultLogger::get()->warn("Collada: Unable to resolve effect texture entry \"" + pName + "\", ended up at ID \"" + name + "\".");
  
          //set default texture file name
          result.Set(name + ".jpg");
          ConvertPath(result);
          return 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 = static_cast<unsigned int>(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,static_cast<unsigned int>(MAXLEN-1),static_cast<int32_t>(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';
      }
  
    // Maxon Cinema Collada Export writes "file:///C:\andsoon" with three slashes...
    // I need to filter it without destroying linux paths starting with "/somewhere"
    if( ss.data[0] == '/' && isalpha( ss.data[1]) && ss.data[2] == ':' )
    {
      ss.length--;
      memmove( ss.data, ss.data+1, ss.length);
      ss.data[ss.length] = 0;
    }
  
    // find and convert all %xy special chars
    char* out = ss.data;
    for( const char* it = ss.data; it != ss.data + ss.length; /**/ )
    {
      if( *it == '%' && (it + 3) < ss.data + ss.length )
      {
        // separate the number to avoid dragging in chars from behind into the parsing
        char mychar[3] = { it[1], it[2], 0 };
        size_t nbr = strtoul16( mychar);
        it += 3;
        *out++ = (char)(nbr & 0xFF);
      } else
      {
        *out++ = *it++;
      }
    }
  
    // adjust length and terminator of the shortened string
    *out = 0;
    ss.length = (ptrdiff_t) (out - ss.data);
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads a float value from an accessor and its data array.
  ai_real 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 unique name for a node derived from the collada-node's properties.
  // The name must be unique for proper node-bone association.
  std::string ColladaLoader::FindNameForNode( const Collada::Node* pNode)
  {
      // Now setup the name of the assimp node. The collada name might not be
      // unique, so we use the collada ID.
      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 format() << "$ColladaAutoName$_" << mNodeNameCounter++;
      }
  }
  
  #endif // !! ASSIMP_BUILD_NO_DAE_IMPORTER
  