title: SCNScene - Not rendering changes to SKNode made on touchesBegan handler
body: <p>I'm subclassing SKNode and implemening the touchbegan handler. </p>
  
  <p><strong>When user clicks on the node, the node position is changed but the node does not move on screen.</strong></p>
  
  <p>I guess i need to force rendering of the SKScene somehow. </p>
  
  <p>To test i did the following minor changes to the template for games of xcode6. 
  Here the changes to the template:</p>
  
  <p>GameViewControler.swift</p>
  
  <pre><code> let HUD = SKScene(fileNamed: "HUD.sks") 
   scnView.overlaySKScene = HUD
  
   var customNode = CustomNode()
   customNode.text = "touch here"
   customNode.position = CGPointMake(200, 200);
   HUD.addChild(customNode)
  </code></pre>
  
  <p>New class CustomeNode.swift</p>
  
  <pre><code>import Foundation
  import SpriteKit
  
  public class CustomNode:SKLabelNode{
  
  public override init() {
      super.init();
      userInteractionEnabled = true;
  }
  
  public required init(coder aDecoder: NSCoder) {
      fatalError("init(coder:) has not been implemented")
  }
  
  public override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
      position.y = (position.y + 100) % 300 + 100; //does not update on screen
  }  
  </code></pre>
  
  <p>}</p>
  
  <p>If add back the action for the ship it works:</p>
  
  <pre><code>let ship = scene.rootNode.childNodeWithName("ship", recursively: true)!
      ship.runAction(SCNAction.repeatActionForever(SCNAction.rotateByX(0, y: 2, z: 0, duration: 1)))
  </code></pre>
  
  <p>how to force rendering?</p>
  
  <p><strong>UPDATE</strong>
  To clarify the complete code of GameViewControler.swift, removing everthing that is not needed.</p>
  
  <pre><code>import UIKit
  import QuartzCore
  import SceneKit
  import SpriteKit
  
  class GameViewController: UIViewController {
  
      override func viewDidLoad() {
          super.viewDidLoad()
  
          // create a new scene
          let scene = SCNScene(named: "art.scnassets/ship.dae") //comes with XCode6 Game Project Template.
  
          // create and add a camera to the scene
          let cameraNode = SCNNode()
          cameraNode.camera = SCNCamera()
          scene?.rootNode.addChildNode(cameraNode)
  
          // place the camera
          cameraNode.position = SCNVector3(x: 0, y: 0, z: 15)
  
           // retrieve the SCNView
          let scnView = self.view as SCNView
  
          // set the scene to the view
          scnView.scene = scene
  
          // allows the user to manipulate the camera
          scnView.allowsCameraControl = true
  
          // configure the view
          scnView.backgroundColor = UIColor.blackColor()
  
          let HUD = SKScene(size: self.view.bounds.size)
          scnView.overlaySKScene = HUD
          scnView.overlaySKScene.userInteractionEnabled = true;
  
          var customNode = CustomNode()
          customNode.text = "touch here"
          customNode.position = CGPointMake(200, 200);
          HUD.addChild(customNode)
  
          //let ship = scene.rootNode.childNodeWithName("ship", recursively: true)!
          //ship.runAction(SCNAction.repeatActionForever(SCNAction.rotateByX(0, y: 2, z: 0, duration: 1)))
      }
  }
  </code></pre>