anchor.diff:  
   
   
  -const String _shadows_vertex_projection = """
  -void drawShadow(in vec3 l, in vec4 v) {
  -  float slopeX = (l.y - v.y) / (l.x - v.x);
  -  float slopeZ = (l.y - v.y) / (l.z - v.z);
  - 
  -  v.y = 0.0;
  -  v.x = l.x - (l.y / slopeX);
  -  v.z = l.z - (l.y / slopeZ);
  - 
  -  gl_Position = pMatrix * mVMatrix * v;
  -  frontColor = vec4(0.0, 0.0, 0.0, 1.0);
  -}
  -
  -""";
  -
  -
  -
  -
   
   
   
  
positive.code:   gl_Position = uProjectionMat * vPosition;
  
    mat3 normalMat = getNormalMat(modelViewMat);
    vec3 normal = normalize(aNormal * normalMat);
  
    highp vec3 ambientLight = vec3(0.6, 0.6, 0.6);
    highp vec3 directionalLightColor = vec3(0.5, 0.5, 0.75);
  
negative.code:    mat4 modelViewMat = uViewMat * uModelMat;
     mat4 skinMat = modelViewMat * accumulateSkinMat();
     mat3 normalMat = getNormalMat(skinMat);
     normalMat = uNormalMat;
  
     vPosition = skinMat * vec4(aPosition, 1.0);
     gl_Position = uProjectionMat * vPosition;
  
     vTexcoords = aTexcoords;
     vNormal = normalize(normalMat * aNormal);
  //   vNormal =  aNormal * normalMat;
  //   vLightDir = normalize(uLightPos - vPosition.xyz);
  //   vEyeDir = normalize(-vPosition.xyz);
  }
  