We’ve got a picture of a model (in this case, the Stanford bunny model). It consists of thousands of tiny triangles that make a surface. Then, imagine a cube surrounding the entire model. If there are two many triangles in that cube, you cut the cube in to eight smaller cubes, and repeat. What this build is a tree where “busy” portions of the space get divided more.

And now for pretty pictures:

The bunny on its own. There are tricks to smooth it out, but I left it highly triangulated to better represent the idea.

Bunny with balanced wireframe octtree around it.

Profile of the bunny with a very deep octtree.

I’m finishing up the implementation, and then I’ll be using it as part of my octtree as a intersection speedup.