title: Augmented Reality App in Landscape Mode
body: <p>I am trying to build an augmented reality app using the CoreMotion framework. I have tried to go off of Apple's pARk sample code project, but it only works in portrait mode. I need it to work in landscape. When switched to landscape mode the subviews in the overlay view move in the opposite directions and at the wrong rate (they either move too fast or too slow across screen)</p>
  
  <p>I have read <a href="https://stackoverflow.com/questions/5063697/ios-4-core-motion-attitude-in-landscape-orientation">other postings</a> that provide two solutions:</p>
  
  <ul>
  <li><p>Create a reference attitude and apply the inverse of that attitude to the current attitude, as suggested in the CoreMotion Tea Pot Example.</p></li>
  <li><p>Rotate the quaternion representation of the attitude 90 degrees</p></li>
  </ul>
  
  <p>I do not think that the first will work because my augmented reality app requires that it be referenced to true north.</p>
  
  <p>I also do not understand the math required to do the second.</p>
  
  <p>Any suggestions on how to accomplish this complex problem I welcome.</p>