Seonglae Cho같은 픽셀에서 여러 물체중 어떤걸 표출할지 정하기 위해
but not enough memory to store all object
ray tracing 에서는 그냥 제일 가까운 거 찾음
- camera to origin
matrix composed with unit axis vector
- frustum to box
- box to unit box
www.cs.ucr.edu
https://www.cs.ucr.edu/~craigs/courses/2022-fall-cs-130/lectures/pipeline-transforms.pdf