<World>
   <Camera eye="50, 50, 300" dir="0,0,-1" fov="60" />
   
   <ShaderGroup>color Cs 0.75 0.25 0.25; shader matte layer1;</ShaderGroup>
   <Quad corner="0, 0, 0" edge_x="0,100,0" edge_y="0,0,150" /> <!-- Left -->

   <ShaderGroup>color Cs 0.25 0.25 0.75; shader matte layer1;</ShaderGroup>
   <Quad corner="100, 0, 0" edge_x="0,0,150" edge_y="0,100,0" /> <!-- Right -->
   
   <ShaderGroup>color Cs 0.25 0.25 0.25; shader matte layer1;</ShaderGroup>
   <Quad corner="0, 0, 0" edge_x="100,0,0" edge_y="0,100,0" /> <!-- Back -->
   <Quad corner="0, 0, 0" edge_x="0,0,150" edge_y="100,0,0" /> <!-- Botm -->
   <Quad corner="0,100,0" edge_x="100,0,0" edge_y="0,0,150" /> <!-- Top  -->

   <ShaderGroup>color Cs 0.35 0.35 0.35; shader matte layer1;</ShaderGroup>
   <Sphere center="73,16.5,78"        radius="16.5" /> <!-- Grey -->

   
   <ShaderGroup>float eta 15; shader metal layer1;</ShaderGroup>
   <Sphere center="27,16.5,47"        radius="16.5" /> <!-- Mirror -->

   <ShaderGroup>float power 26000; shader emitter layer1</ShaderGroup>
   <Quad corner="40, 99.99, 40" edge_x="20, 0, 0" edge_y="0, 0, 20" is_light="yes" /> <!--Lite -->
   
</World>
