A FAST little raymarcher in Scratch :) Wanted to try an algo nobody else had done in Scratch; there seem to be a few decent classic Whitted raytracers but I THINK this is the first raymarcher (aka sphere tracer). There's a rather cunning trick used for cheap diffuse lighting, see if you can figure it out. The nice thing about raymarching as opposed to classic raytracing is that you can easily do domain tricks like repetition and distortion; the performance can be MUCH MUCH higher too. It's also much easier to come up with distance-to-surface functions than ray-surface intersection functions -- so download it and play with it and see if you can come up with some interesting geometry :)
