title: What does (gl_FragCoord.z / gl_FragCoord.w) represent?
body: <p>I want actual world space distance, and I get the feeling from experimentation that</p>
  
  <p><code>(gl_FragCoord.z / gl_FragCoord.w)</code></p>
  
  <p>is the depth in world space? But I'm not too sure.</p>
  
  <p><strong>EDIT</strong> I've just <a href="http://www.ozone3d.net/tutorials/glsl_fog/p04.php" rel="noreferrer">found where I had originally located this snippet of code</a>. Apparently it is the actual depth from the camera?</p>