title: How to set up skybox in Autodesk Forge
body: <p>I want to add a skybox to my Forge scene, but Forge is different from three.js. I want to know what I can do for it.</p>
  
  <p>I have tried <code>new THREE.CubeTextureLoader</code>, but the three.js in Forge doesn't have this function. Then I tried to build a <code>CubeGeometry</code>, but it did't work well.</p>
  
  <p>This is my code:</p>
  
  <pre><code>var materialArr=[];
  var directions = ["aa_RT","aa_LF","aa_UP","aa_DN","aa_FR","aa_BK"]  ;
  for (var i = 0; i &lt; 6; i++){
      materialArray.push( new THREE.MeshBasicMaterial({
        map: THREE.ImageUtils.loadTexture( "lib/img/aa/"+ directions[i] + ".jpg" ),
        side: THREE.BackSide
      }));
   }
  var skyBoxGeom = new THREE.CubeGeometry(80,80,80);
  var skyBoxMaterial = new THREE.MeshFaceMaterial(materialArr);
  var skyBox = new THREE.Mesh(skyBoxGeom,skyBoxMaterial);
  viewer.impl.scene.add(skyBox);
  </code></pre>
  
  <p>This is my scene:</p>
  
  <p><img src="https://i.stack.imgur.com/kPo1g.jpg" alt="scene"></p>