Attempt at real-time path tracing on the CPU. Yet another one of those problems that could use a 1000x faster CPU. The path tracer is simple; no bidirectional path tracing nor metropolis light transport. Initially inspired by smallpt. It traces against a Build engine-like 2.5D structure (so guess where "ks" came from).
The above 192x108 screenshot renders at 7 frames per second using all 4 cores on my Intel(R) Core(TM) i5-3230M CPU @ 2.60GHz laptop CPU (according to /proc/cpuinfo). That's about 7 million ray traces per second, each with up to 4 bounces.