   Two questions
  HelloI''m half way into LaMothes "Tricks of the 3D game programming gurus" and I got two questions.What is camera transformation good for, is it to aid clipping and culling (or got it other advantages)?The perspective transformation has following formulas: Xper=viewing_distance*Xcamera/Zcamera, Yper=viewing_distance*aspect_ratio*Ycamera/Zcamera, aspect_ratio=width/height. According to the book the ranges is X:-1 to 1, Y: -1/ar to 1/ar (FOV 90, viewing_distance 1.0). Are these formulas really valid? It seam to me that Y: -1*ar to 1*ar, and if so should''nt Y be thighter than X. 