title: Understanding CATransform3D
body: <p>I'm playing with CATransform3DMakeRotation in a UIView, and I'm trying to do a 45º, transform like it's laying backwards:</p>
  
  <p><img src="https://i.stack.imgur.com/re4uM.png" alt="http://cl.ly/2A2p1W1e2N3a1W181r35"></p>
  
  <p>This is the "code" I have, but clearly doesn't do it.</p>
  
  <pre><code>CATransform3D _tr = CATransform3DMakeRotation(3.14/4, 1, 0, 0);
  view.layer.transform = _tr;
  </code></pre>
  
  <p>please help me understand the params.
  Thanks.</p>