It’s fun to play with in Web form, but most impressive is “Adjustment of crowd simulation to art animation”, which links to a video. It’s a terrific demonstration of the advantage of Processing, working in true three-dimensional space even with 2D drawing routines. Underneath the patch is a sophisticated node garden, which you can see in action in the alternate rendering mode. By doing progressive drawing between the nodes, the whole work becomes organic, mysterious, and beautiful. Source code is included, though it’s specific enough to this project that you’re best off going your own direction.