Ellipsoid Frustum Intersection
Yesterday I posted a problem to math stack exchange that bothered me for a while now, and right after I've had a few exchanges on Twitter, I got inspired to attempt a solution.
Here it goes. It's 100% untested but I'm fairly certain that it will work.
The problem is about a form of refining raytracing where we render a big list of convex 3D brushes (and I decided to start with Ellipsoids, since they're so useful) to the screen or a shadow map, without any prebuilt accelleration structure. How does it work? Well, if we had a way to figure out for a portion of the frustum whether it contained a brush, we could
- Start with a very low resolution