title: ARKit billboarding effect with SceneKit
body: <p>I am looking to add a billboarding effect that is similar to this application: <a href="https://twitter.com/marpi_/status/897130955105644544" rel="noreferrer">https://twitter.com/marpi_/status/897130955105644544</a></p>
  
  <p>I would like SCNodes that use SCNText geometry to always face the camera. </p>
  
  <p>I have attempted with out success: </p>
  
  <ul>
  <li>SCNLookAtConstraint with sceneView.pointOfView as the target, but this rotates the node to face away from the camera, resulting in backwards text, and unable to change the nodes position or euler angle. </li>
  </ul>
  
  <p>Out of the box, an SKLabelNode will always face the camera in ARKit, which is exactly what I want, except using SCNText.</p>