title: The wireframe view does not show the model
body: <p>I'm using the object-loader to load a basic cube (geometry), and I wanted to get a wireframe view.</p>
  
  <p>It doesn't appear!</p>
  
  <p>When I use (otherGeometry) - from a three.js primitive, it renders it fine with this code:</p>
  
  <pre><code>&lt;script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/90/three.min.js"&gt;&lt;/script&gt;
  &lt;script src="https://threejs.org/examples/js/controls/OrbitControls.js"&gt;&lt;/script&gt;
  &lt;script src="https://threejs.org/examples/js/loaders/OBJLoader.js"&gt;&lt;/script&gt;
  
  var material = new THREE.MeshBasicMaterial({color: 0xffffff});
  var objLoader = new THREE.OBJLoader();
  
  var geometry = objLoader.parse(testObj);
  var otherGeometry = new THREE.BoxGeometry(100, 100, 5);
  
  var geo = new THREE.WireframeGeometry(geometry);
  var mat = new THREE.LineBasicMaterial({color: 0xff0000, linewidth: 1});
  var wireframe = new THREE.LineSegments(geo, mat);
  scene.add(wireframe);
  
  var testObj = `# cube.obj
  #
  g cube
  
  v  0.0  0.0  0.0
  v  0.0  0.0  1.0
  v  0.0  1.0  0.0
  v  0.0  1.0  1.0
  v  1.0  0.0  0.0
  v  1.0  0.0  1.0
  v  1.0  1.0  0.0
  v  1.0  1.0  1.0
  
  vn  0.0  0.0  1.0
  vn  0.0  0.0 -1.0
  vn  0.0  1.0  0.0
  vn  0.0 -1.0  0.0
  vn  1.0  0.0  0.0
  vn -1.0  0.0  0.0
  
  f  1//2  7//2  5//2
  f  1//2  3//2  7//2 
  f  1//6  4//6  3//6 
  f  1//6  2//6  4//6 
  f  3//3  8//3  7//3 
  f  3//3  4//3  8//3 
  f  5//5  7//5  8//5 
  f  5//5  8//5  6//5 
  f  1//4  5//4  6//4 
  f  1//4  6//4  2//4 
  f  2//1  6//1  8//1 
  f  2//1  8//1  4//1`;
  </code></pre>