Culling
The process of removing polygons facing away from the camera relative to the
orientation of each polygon and the camera.
We do this using an [see page 10, equation] based on the polygon normal, the line of sight vector for the camera and the angle between them.
\[ N_p . S = |N_p| |S| cos \theta \]
A polygon is only visible if \(N_p . S \gt 0\) where:
- \( S \) is the line of sight vector (can be just any vertex on the polygon).
- \( N_p \) is the polygon normal.
- θ is the angle between \(N_p\) and \(s\).
Warn: culling only removes polygons facing away from your camera, overlapping polygons in front of your camera are still visible. To remove those you need HSR.