var lib = {
   "normal": "",
   'cube': new THREE.ShaderMaterial(

     uniforms: {
       "tCube": new THREE.Uniform.float(),
       "tFlip": new THREE.Uniform.float(-1.0)
       },

     vertexShader:
        '''varying vec3 vViewPosition;
           void main() {
             vec4 mPosition = modelMatrix * vec4( position, 1.0 );
             vViewPosition = cameraPosition - mPosition.xyz;
             gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
           }''',


     fragmentShader:
        '''uniform samplerCube tCube;
           uniform float tFlip;
           varying vec3 vViewPosition;
           void main() {
             vec3 wPos = cameraPosition - vViewPosition;
             gl_FragColor = textureCube( tCube, vec3( tFlip * wPos.x, wPos.yz ) );
           }'''
         )

}