title: three.js: How to add materials array to octahedron geometry
body: <p>I would like to add multiple materials to a <code>THREE.OctahedronGeometry</code>. This works fine for box objects, but for <code>THREE.OctahedronGeometry</code> I just get the first material on all faces. How can I get a different material on each face? </p>
  
  <pre><code>        var geometry = new THREE.OctahedronGeometry(1, 0);
  
          var materials = [
              new THREE.MeshPhongMaterial( { color: 0x050505, dithering: true } ),
              new THREE.MeshPhongMaterial( { color: 0xeeeeee, dithering: true } ),
              new THREE.MeshPhongMaterial( { color: 0x060606, dithering: true } ),
              new THREE.MeshPhongMaterial( { color: 0xeeeeee, dithering: true } ),
              new THREE.MeshPhongMaterial( { color: 0x050505, dithering: true } ),
              new THREE.MeshPhongMaterial( { color: 0xeeeeee, dithering: true } ),
              new THREE.MeshPhongMaterial( { color: 0x070707, dithering: true } ),
              new THREE.MeshPhongMaterial( { color: 0xeeeeee, dithering: true } )
          ];
  
          var someMesh = new THREE.SceneUtils.createMultiMaterialObject( geometry , materials );
  
          someMesh.castShadow = true; //default is false
          someMesh.receiveShadow = true; //default
          scene.add( someMesh );
  </code></pre>