title: Adding 3D to 2D game
body: <p>I am making a top-down platformer game using sprites.  I would like to add some 3d elements to add depth to the platforms, by drawing the platforms as pillars that extend down into the abyss.  The concept is illustrated in the image below.</p>
  
  <p>My problem arises in trying to align the top of the 3d model with the platform sprite. How would I design a system that automatically creates a pillar in the proper position whenever I draw a platform object?</p>
  
  <p><a href="http://i.stack.imgur.com/qIhMW.png" rel="nofollow">Sample image</a></p>