So I've been sitting on some mostly finished code to vectorize anti-aliased images for quite some time. It uses marching squares to extract a subpixel (or hard pixel) boundary, then simplifies the curves. It can also generate convex hulls, but I haven't implemented convex decomposition yet. It's fast enough to do realtime deformable terrain.

It's a paid part of Objective-Chipmunk/Chipmunk Pro that is currently included with Objective-Chipmunk (as of 5.3.5 heh) in an as-is-not-finished state. So we aren't just giving it all away.

Even if you aren't using Chipmunk in your entry, it's a more or less completely separate component. You can use it to get a vector contour of a terrain image or sprites and generate convex hulls for them. Currently it only has a simple C API so it should be easy to integrate into whatever language you are using.

Send me an email at slembcke on gmail if you have entered the competition and you are interested in helping us test it out and make API suggestions. I'll probably use it as an offline tool for my game and I Diordna was thinking about using it for his Worms style game for realtime terrain.