title: .vertices array does not give the vertices in THREE.js
body: <p>I am using OBJloader to load an .obj file in WEBGL , Three.js.
  I want to access the vertices and faces of the objects but the geometry.vertices does not return the vertices positions and it gives me undefined.</p>
  
  <p>Here is a piece of code:</p>
  
  <pre><code> var tool= new THREE.OBJLoader();
   tool.load( '../obj/tool.obj', function ( object ) {
              var material = new THREE.MeshLambertMaterial({color:0xA0A0A0});             
              object.traverse( function ( child ) {
                  if ( child instanceof THREE.Mesh ) {
                     child.material = material;
                     console.log( "child" + child.geometry.vertices);} }
  </code></pre>
  
  <p>r.70</p>
  
  <p>I am thankful for your helps in advance.</p>