Bugfix: collada loader now preserves empty data arrays to work around stupid exporters writing empty animation channels

git-svn-id: https://assimp.svn.sourceforge.net/svnroot/assimp/trunk@1246 67173fc5-114c-0410-ac8e-9d2fd5bffc1f

code/ColladaLoader.cpp

@@ -926,7 +926,7 @@ void ColladaLoader::CreateAnimation( aiScene* pScene, const ColladaParser& pPars
 			const Collada::AnimationChannel& srcChannel = *cit;
 			Collada::ChannelEntry entry;
 
-			// we except the animation target to be of type "nodeName/transformID.subElement". Ignore all others
+			// 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)
@@ -995,18 +995,23 @@ void ColladaLoader::CreateAnimation( aiScene* pScene, const ColladaParser& pPars
 			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));
 
+      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.
 		  float time = startTime;
-		std::vector<aiMatrix4x4> resultTrafos;
 		  while( 1)
 		  {
 			  for( std::vector<Collada::ChannelEntry>::iterator it = entries.begin(); it != entries.end(); ++it)
@@ -1084,11 +1089,14 @@ void ColladaLoader::CreateAnimation( aiScene* pScene, const ColladaParser& pPars
 			  // else construct next keyframe at this following time point
 			  time = nextTime;
 		  }
+    }
 
-		// there should be some keyframes
+		// there should be some keyframes, but we aren't that fixated on valid input data
-		ai_assert( resultTrafos.size() > 0);
+//		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 = resultTrafos.size();
@@ -1111,6 +1119,10 @@ void ColladaLoader::CreateAnimation( aiScene* pScene, const ColladaParser& pPars
 		  }
 
 		  anims.push_back( dstAnim);
+    } else
+    {
+      DefaultLogger::get()->warn( "Collada loader: found empty animation channel, ignored. Please check your exporter.");
+    }
 	}
 
 	if( !anims.empty())

code/ColladaParser.cpp

@@ -1647,6 +1647,7 @@ void ColladaParser::ReadDataArray()
 {
 	std::string elmName = mReader->getNodeName();
 	bool isStringArray = (elmName == "IDREF_array" || elmName == "Name_array");
+  bool isEmptyElement = mReader->isEmptyElement();
 
 	// read attributes
 	int indexID = GetAttribute( "id");
@@ -1654,13 +1655,15 @@ void ColladaParser::ReadDataArray()
 	int indexCount = GetAttribute( "count");
 	unsigned int count = (unsigned int) mReader->getAttributeValueAsInt( indexCount);
 	const char* content = TestTextContent();
-	if (content) { // some exporters write empty data arrays, silently skip over them
 
   // read values and store inside an array in the data library
   mDataLibrary[id] = Data();
   Data& data = mDataLibrary[id];
   data.mIsStringArray = isStringArray;
 
+  // some exporters write empty data arrays, but we need to conserve them anyways because others might reference them
+  if (content) 
+  { 
 		if( isStringArray)
 		{
 			data.mStrings.reserve( count);
@@ -1695,10 +1698,11 @@ void ColladaParser::ReadDataArray()
 				SkipSpacesAndLineEnd( &content);
 			}
 		}
+	}
 
   // test for closing tag
+  if( !isEmptyElement )
     TestClosing( elmName.c_str());
-	}
 }
 
 // ------------------------------------------------------------------------------------------------