title: Why there is some translation element in Opengl Modelview matrix even when we perform a simple rotation?
body: <p>I am doing a simple rotation around x axis in opengl as:</p>
  
  <pre><code> glRotatef(rx,1,0,0);
  </code></pre>
  
  <p>I calculated the translation vector from Modelview matrix before and after this operation. What I found surprising was that even we don't see any translation happening on the screen, but still there is some residue translation in the Modelview matrix. Can anyone explain the reason behind that or is it that I am assuming something wrong here.</p>
  
  <p>PS: For calculating the translation vector I have taken transpose of the inversion of ModelView matrix. </p>