I'm wondering if it's possible to use or hack Bullet 3d Physics (or another free 3D physics engine) so that I don't need to "import" my static geometry into Bullet - instead I want to do it the other way, so Bullet uses some sort of callback system to check geometry properties of my mesh/polygons.
Sort of like that Bullet would expect a method in my static geometry classes "checkRayIntersection" or similar, and I take care of the details and optimizations myself. The meshes are immovable, so the only thing that I expect Bullet to care about is intersections and their normals, but I might be missing something..
EDIT: as an example, consider a 10 million polygon terrain mesh which is changing all the time. You probably don't want to keep parallel data structures in the render-engine and in the physics engine for this. You don't want to use an approximation for the physics either.
Bullet uses something called MotionStates to solve this problem for its output - I was hoping there was a similar design pattern for passing geometry input.