gistfile1.coffee

  # Add custom shader
  # http://www.html5rocks.com/en/tutorials/webgl/shaders/
  vertexShader = """
    // create a shared variable for the
    // VS and FS containing the normal
    varying vec3 vNormal;
  
    void main() {

        // set the vNormal value with
        // the attribute value passed
        // in by Three.js
        vNormal = normal;
  
        gl_Position = projectionMatrix *
                      modelViewMatrix *
                      vec4(position,1.0);
    } 
  """ 
  fragmentShader = """
    // same name and type as VS
    varying vec3 vNormal;

    void main() {
        
        // calc the dot product and clamp
        // 0 -> 1 rather than -1 -> 1
        vec3 light = vec3(0.5,0.2,1.0);
          
        // ensure it's normalized
        light = normalize(light);
      
        // calculate the dot product of
        // the light to the vertex normal
        float dProd = max(0.0, dot(vNormal, light));
      
        // feed into our frag colour
        gl_FragColor = vec4(dProd, dProd, dProd, 1.0);
      
    }
  """
  shaderMaterial = new THREE.ShaderMaterial({vertexShader, fragmentShader})