Playing with multiple shadows, the program generates real-time shadows casted from a set of six lights revolving around.

The program works also on more complex shadow casting objects. I have done similar thing on objects with more complex shapes, and will post them later. Sometimes, the Interplay of lights and shadows can be quite enticing. 

(The video is directly output from computer screen dump, the program is running at real-time frame-rate generating the shadows.)

Note: The video has no sound or music background, which I think is better this way.