title: ARKit Place a SCNNode facing the camera
body: <p>I'm using <code>ARKit</code> to display 3D objects. I managed to place the nodes in the real world in front of the user (aka the camera). But I don't manage to make them to face the camera when I drop them. </p>
  
  <pre><code>let tap_point=CGPoint(x: x, y: y)
  let results=arscn_view.hitTest(tap_point, types: .estimatedHorizontalPlane)
  guard results.count&gt;0 else{
      return
  }
  guard let r=results.first else{
      return
  }
  
  let hit_tf=SCNMatrix4(r.worldTransform)
  let new_pos=SCNVector3Make(hit_tf.m41, hit_tf.m42+Float(0.2), hit_tf.m43)
  
  guard let scene=SCNScene(named: file_name) else{
      return
  }
  guard let node=scene.rootNode.childNode(withName: "Mesh", recursively: true) else{
      return
  }
  node.position=new_pos
  arscn_view.scene.rootNode.addChildNode(node)
  </code></pre>
  
  <p>The nodes are well positioned on the plane, in front of the camera. But they are all looking in the same direction. I guess I should <strong>rotate</strong> the <code>SCNNode</code> but I didn't manage to do this. </p>