otoy was more open earlier; they've since locked it down a bit, but with some googling you can dig it out (eg: http://raytracey.blogspot.com/2008/08/otoy-transformers-and-... , links-> http://ompf.org/forum/viewtopic.php?f=6&t=882 ).

In earlier interviews Urbach spoke about a very fast gpu-assisted transform from polygon meshes -> voxels for use in their raytracer (and some hybrid meshes); the use of such a thing for making demo videos should be pretty obvious.

The video compression aspect is also interesting and probably works as you say; the point of raytracing isn't that it's faster per-se but that not having to keep transforming your scene data means you can more-easily share scene data between multiple simultaneous users on the same box (loosely: you don't need space for N translated copies of the scene data if you have N simultaneous users).