title: Time-based variation / animation of OpenGL primitives
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/14187346/how-to-use-a-timer-inside-a-vertex-shader-to-animate-point-sizes-in-opengl">How to use a timer inside a vertex shader to animate point sizes in OpenGL</a>  </p>
  </blockquote>
  
  
  
  <p>I'd like to implement an animation effect in OpenGL where my point primitives shall vary in size and transparency over time, based on a value associated with each vertex. This data is stored inside a VBO and passed to a vertex shader.</p>
  
  <p>The whole process of how such an animation effect could be achieved is unclear to me, so I hope to get an answer that describes how animation can be done and what steps are necessary.</p>
  
  <p>I've asked this question before but didn't get a satisfying answer, which is why I post this question again: a link to the previous question can be found <a href="https://stackoverflow.com/questions/14187346/how-to-use-a-timer-inside-a-vertex-shader-to-animate-point-sizes-in-opengl">here</a></p>
  
  <p>I'm using OpenGL 4.2 and I would be more than happy if you could tell me how to render a single point in space which varies in size and alpha value!</p>