I recently finished this math library (available here, licensed under the lgpl) for my own engine and, knowing how hard 3d math can be, offer it to you. The code here is mostly LGPL code from the Ogre graphics engine (which is in turn mostly from wildmagic 3), with modifications to allow for access to the Vector3 and Quaternion classes from python using boost::python. It all uses fast methods and has good algorithms for things like ray/aabb and aabb/planeBoundedVolume intersections. The files are also all standalone, so that if you add them to your project you don't need to link in any .lib's or .so's or anything to make it work. 3d math has always been a major pain for me so I hope that this will save someone a headache.