title: Compact representation of OpenGL modelview matrix 4x4
body: <p>What is the most user friendly way to store only the rotation part of an OGL modelview (4x4) matrix?</p>
  
  <p>For example; in a level editor to set the rotation for an object it would be easy to use the XYZ Euler angles. However this seems a very tricky system to use with matrices. </p>
  
  <p>I need to be able to get AND set the rotation from this new representation. </p>
  
  <p>(The alternative is to store the rotation part (4*3 numbers) but it is hard for a user to manipulate these)</p>
  
  <p>I found some code here <a href="http://www.google.com/codesearch/p?hl=en#HQY9Wd_snmY/mesh/matrix3.h&amp;q=matrix3&amp;sa=N&amp;cd=1&amp;ct=rc" rel="nofollow">http://www.google.com/codesearch/p?hl=en#HQY9Wd_snmY/mesh/matrix3.h&amp;q=matrix3&amp;sa=N&amp;cd=1&amp;ct=rc</a> that allows me to set and get rotation from angles (3 floats). This is ideal.</p>