title: geometry of the node from dae file is nil
body: <p>I've made 3d model with blender and I want to use it in scene kit.</p>
  
  <pre><code>var platform = SCNNode();
  let dae = SCNScene(named:"platform.dae");
  platform = dae!.rootNode;
  platform.position = SCNVector3(x: 0,y: 0,z:0);
  if platform.geometry == nil {
      print("geo is nil.")
  }
  platform.geometry?.firstMaterial?.diffuse.contents = "wood.png";
  platform.geometry?.firstMaterial?.diffuse.wrapS = SCNWrapMode.Repeat
  platform.geometry?.firstMaterial?.diffuse.wrapT = SCNWrapMode.Repeat
  platform.physicsBody = SCNPhysicsBody(type: SCNPhysicsBodyType.Static, shape: SCNPhysicsShape(node: platform, options: nil));
  scene.rootNode.addChildNode(platform);
  </code></pre>
  
  <p>It always prints out "geo is nil". So I can't make a physics body for the model. Can anyone tell me why does this happen?</p>