anchor.diff:  
   final double kAnimTimeStep = 0.0333;
   
  +class BoneVisualizer {
  +  VM.Matrix4 _globalOffsetTransform = new VM.Matrix4.identity();
  +  MeshData _mdWire;
  +  List<Bone> _skeleton;
  +  SkeletalAnimation _anim;
  +  AnimatedSkeleton _animatedSkeleton;
  +
  +  Node mesh;
  +
  +  BoneVisualizer(ChronosGL cgl, Material mat, this._skeleton, this._anim) {
  +    _animatedSkeleton = new AnimatedSkeleton(_skeleton.length);
  +    UpdateAnimatedSkeleton(
  +        _skeleton, _globalOffsetTransform, _anim, _animatedSkeleton, 0.0);
  +    _mdWire = LineEndPointsToMeshData(
  +        "wire", cgl, BonePosFromAnimatedSkeleton(_skeleton, _animatedSkeleton));
  +    mesh = new Node(_mdWire.name, _mdWire, mat);
  +  }
  +
  +  void Update(double time) {
  +    UpdateAnimatedSkeleton(_skeleton, _globalOffsetTransform, _anim,
  +        _animatedSkeleton, time % _anim.duration);
  +    List<VM.Vector3> bonePos =
  +        BonePosFromAnimatedSkeleton(_skeleton, _animatedSkeleton);
  +    _mdWire.ChangeVertices(FlattenVector3List(bonePos));
  +  }
  +}
  +
   void main() {
     StatsFps fps =
         new StatsFps(HTML.document.getElementById("stats"), "blue", "gray");
  
positive.code:       animationSteps.add(t);
      }
  
      animatedSkeleton = new AnimatedSkeleton(skeleton.length);
  
      {
        Float32List animationData = CreateAnimationTable(
            skeleton, globalOffsetTransform, anim, animationSteps);
  
negative.code:   //RenderProgram prg = phase.createProgram(createDemoShader());
    final RenderProgram prgAnim = phase.createProgram(createAnimationShader());
    final RenderProgram prgSimple = phase.createProgram(createDemoShader());
    final RenderProgram prgBone = phase.createProgram(createSolidColorShader());
    final Material matWire = new Material("wire")
      ..SetUniform(uColor, ColorYellow);
  
    final Material mat = new Material("mat");
    TypedTexture animationTable;
    List<double> animationSteps;
    BoneVisualizer boneVisualizer;
  
    Map<String, RenderProgram> programMap = {
      "idSkeleton": prgBone,
  