SSAO Coding Battle!!!

Yesterday I was talking with David from Wolfire about Screen Space Ambient Occlusion, a lighting technique that adds some depth to the scene.  Since we had talked about it a few times before we decided stop talking about it and have a competition to see who could implement it in their game first.  About a half-hour later, just after I had decided which album to play while I work on it David had it working in Overgrowth.  Still I pressed on and eventually got it working in A New Zero.

I really hacked it in so there's a lot of artifacts, but what I ended up with was casting 16 spherical rays from each pixel, using the depth of the ray compared to the depth of the pixel it's at, and using a soft comparison to tell how much occlusion there is.  It has a lot of inaccurate highlights around edges but I kind of like it, I'll probably keep messing around with it until I have a style that works.  It's definitely a good technique for ANZ since it can be used in dynamic scenes and adds a lot of depth to the not very textured world of A New Zero.

Check out David's video at: http://blog.wolfire.com/2011/12/Overgrowth-a161-video-changelog