title: How to get a SCNNode to face the current camera position?
body: <p>I'm currently programming an AR-App, which starts with placing a SCNNode (table). First the app searches for a horizontal plane and whenever a surface was found, the object is shown, but not placed yet. While it is not placed, I want the object to face the camera at all times, but I'm having trouble to find the current position of the camera and also updating the object every frame.</p>
  
  <p>Currently, the object is facing the world coordinates. So when I start the app and a horizontal plane was found - the object appears and faces to the starting point of the world coordinates (wherever I started the app)</p>
  
  <p>Can anybody help me, how to get the vector from the camera position and make the object updates it's direction every frame? </p>
  
  <pre class="lang-swift prettyprint-override"><code>var tableNode : SCNNode!  // Node of the actual table
  
  var trackingPosition = SCNVector3Make(0.0, 0.0, 0.0)
  
  let trans = SCNMatrix4(hitTest.worldTransform)
  
  self.trackingPosition = SCNVector3Make(trans.m41, trans.m42, trans.m43)
  
  self.tableNode.position = self.trackingPosition
  </code></pre>