level of detail

Josh Barczak (colleague of mine at both ATI and Firaxis) has posted a templated raytracing codebase to SourceForge. It has implementations of BVH, QBVH, uniform grid, and KD-tree acceleration structures. It looks like a good starting point for a renderer or just experimentation. The code is really clean and it comes with a few example projects to get you started. Check it out.

TinyRT