title: Three.js Calculating Vertex Normals
body: <p>I'm experimenting with one of the examples, namely the webgl_loader_obj.html to load an .obj file exported from blender into three.js</p>
  
  <p>This works and displays the model exactly as expected.
  Now i was looking at the use of material.shading = THREE.SmoothShading.</p>
  
  <p>For this to work, the model needs to have vertex normals.
  the exported file from blender has no normals defined.</p>
  
  <p>So i looked at using computeVertexNormals to calculate the required normals.
  however this doesn't appear to be doing anything, the resulting view is of the unsmoothed model.</p>
  
  <p>further to this, as a test, i exported the same model, with normals.
  loading it straight in, it appeared smoothed.</p>
  
  <p>If i then did computeFaceNormals() &amp; computeVertexNormals() it would result in the unsmoothed mesh again.</p>
  
  <pre><code>var loader = new THREE.OBJLoader( manager );
              loader.load( 'test.obj', function ( object ) {
  
                  object.traverse( function ( child ) {
  
                      if ( child instanceof THREE.Mesh ) {
                          child.material = new THREE.MeshLambertMaterial( { color: 0xff6600 });
  
                          child.geometry.computeFaceNormals();
                          child.geometry.computeVertexNormals();
                          child.material.shading = THREE.SmoothShading;
  
  
                      }
  
                  } );
  </code></pre>