anchor.diff:  import 'dart:html' as HTML;
   import 'dart:async';
   import 'package:vector_math/vector_math.dart' as VM;
  +import "dart:math" as MATH;
   
   const String dir = "../asset/leeperrysmith/";
   const String modelFile = dir + "LeePerrySmith.js";
  
positive.code: 
  List<ShaderObject> createShader() {
    return [
      new ShaderObject("LightBlinnPhongV")
        ..AddAttributeVars([aVertexPosition, aNormal, aTextureCoordinates])
        ..AddVaryingVars([vVertexPosition, vNormal, vTextureCoordinates])
        ..AddUniformVars([uPerspectiveViewMatrix, uModelMatrix, uNormalMatrix])
  
negative.code:         ${vNormal} = ${uNormalMatrix} * ${aNormal};
          """
        ]),
      new ShaderObject("LightBlinnPhongFancyF")
        ..AddVaryingVars([vVertexPosition, vNormal, vTextureCoordinates])
        ..AddUniformVars([uLightDescs, uLightTypes])
        ..AddUniformVars([uEyePosition, uColor])
  