title: OpenGL translation and rotation object
body: <p>I have object which moves around circle. The object is a fish.<br>
  The moving: </p>
  
  <pre><code>mesh-&gt;objectModelMatrix = glm::translate(glm::mat4(1.0f), glm::vec3(5.0f * sin(elapsedTime), initialY, 5.0f * cos(elapsedTime)));
  </code></pre>
  
  <p>I need to calculate rotation to move the fish forward (head first).
  Something like this:</p>
  
  <pre><code>    mesh-&gt;objectModelMatrix = glm::rotate(mesh-&gt;objectModelMatrix, elapsedTime, glm::vec3(0.0f, 0.0f, 1.0f));
  </code></pre>
  
  <p>The non-transformed orientation of the fish has the head pointing to the right.</p>
  
  <p>I can not find the correct formula.</p>