var skySphereJSON = {

 type: "shader",

 shaders: [

  /* Vertex shader with our custom function to intercept the matrix
   */
  {
   stage: "vertex",
   code: [

    "mat4 myViewMatrix(mat4 m) {",
    " m[3][0] =m[3][1] = m[3][2] = 0.0;" +
    " return m; ",
    "}"
   ],

   hooks: {
    viewMatrix: "myViewMatrix" // Bind our custom function to hook
   }
  },

  {
   stage: "fragment",
   code: [
    "vec4 savedWorldPos;",

    "vec4 getWorldPos(vec4 pos) {",
    " savedWorldPos = pos;" +
    " return pos; ",
    "}",

    "vec4 tweakPixelColor(vec4 color) {",
    " color.rgb -= ((savedWorldPos.y-1.5) * 0.01);",
    " return color; ",
    "}"
   ],

   hooks: {
    worldPos: "getWorldPos",
    pixelColor: "tweakPixelColor"
   }
  }
 ],

 nodes: [
  {
   type: "scale",

   x: 1000,
   y: 1000,
   z: 1000,

   nodes: [
    {
     type: "material",

     baseColor: { r: .7, g: .7, b: 1.0 },
     emit: 0.3,

     nodes: [
      {
       type: "sphere"
      }
     ]
    }
   ]
  }
 ]
};