title: Converting 2D projection rotation angles to 3D object
body: <p>I am projecting a 3D matrix of density values into 3 2D planes (ZX,ZY,XY). I then rotate each projection by 3 different angles: Pzx, Pzy, Pxy using the rotation matrix below:</p>
  
  <p><img src="https://i.stack.imgur.com/oZXua.png" alt="2D Rotation Matrix"></p>
  
  <p>How do I convert these 3 separate angles so that I can apply them to a 3D transformation matrix which will rotate the 3D object about X,Y,Z (or Z,Y,X) such as the rotation matrix below:</p>
  
  <p><img src="https://i.stack.imgur.com/SSAty.png" alt="3D Rotation Matrix about X,Y,Z"></p>
  
  <p>To be clear, I do not wish to apply angles Pzx, Pzy, Pxy to the 3D object, but instead calculate what those individual rotations in 2D would translate to in 3D.</p>