Stepping things up a notch. I managed to get real-time raytracing working at an acceptable framerate (with ASCII rendering of course). Play with the demo.
I’m not able to get Chrome and FF to render <pre>’s the same way yet. At the time of writing the demo looks better in FF than Chrome, but it screams in Chrome without any threading. Some credit goes to the author of JayTracer, a canvas-based renderer. I took quite a bit of core code and built upon it, adding optimizations where I saw fit. If anyone wants to further optimize this go ahead.