I'm surprised this field hasn't moved forward as much as I thought. If memory serves me correctly, I remember being shown a cuda based real time ray tracer, wit

I'm surprised this field hasn't moved forward as much as I thought. If memory serves me correctly, I remember being shown a cuda based real time ray tracer, with similar limitations by a masters student in early 2007. They ran into lot's of troubles because of the architecture of cuda itself (e.g. maximum occupancy was never very high on average), but could produce stunning realtime visuals at low framerate (e.g. 640x480). Not different from these guys at all. At higher resolutions it was much, much harder as the solutions didn't scale because of the limitations of cuda. I expected to see him presenting his stuff at siggraph but never did - not sure what happened to him, and an internet search reveals nothing.