title: SCNLookAtConstraint causing zoom past 3D model
body: <pre><code>UPDATE: 
  </code></pre>
  
  <p>After further testing and evaluation it seems that the SCNLookAtConstraint is causing the issue. Basically because it removes the 2 finger Pan Gesture it is causing some weird behavior with the pinch and scroll gesture. Does anyone have a good idea how to fix this? </p>
  
  <pre><code>override func touchesEnded(_ touches: Set&lt;UITouch&gt;, with event: UIEvent?) { 
    let quaternion = sceneView.pointOfView?.orientation
    let position = sceneView?.pointOfView?.position
    print("Orientation: ((quaternion?.x),(quaternion?.y),(quaternion?.z),(quaternion?.w)) Position: ((position?.x),(position?.y),(position?.z)") 
  }
  </code></pre>
  
  <p>but this just prints out the same values now matter the 2 finger zoom pressed.</p>
  
  <pre><code>func setupScene() {
      let scene = SCNScene()
      self.sceneView.scene = scene
  
      let camera = SCNCamera()
      let cameraNode = SCNNode()
      cameraNode.camera = camera
      cameraNode.position = SCNVector3(x: -1.0, y: 0.0, z: -1.0)
      cameraNode.boundingBox.max = SCNVector3(x: 2, y: 2, z: 2)
      cameraNode.boundingBox.min = SCNVector3(x: 0.1, y: 0.1, z: 0.1)
  
      let centerNode = SCNNode()
      centerNode.position = SCNVector3(x: 0.0, y: 0.0, z: 0.0)
  
      let light = SCNLight()
      let lightNode = SCNNode()
      light.type = .ambient
      light.color = UIColor.white
      lightNode.light = light
  
      scene.rootNode.addChildNode(cameraNode)
      scene.rootNode.addChildNode(centerNode)
      scene.rootNode.addChildNode(lightNode)
  
      cameraNode.constraints = [SCNLookAtConstraint(target: centerNode)]
      sceneView.pointOfView = cameraNode
  
  }
  </code></pre>