3D- 4 × 4, , , . (a, b) , (a, b, 0, 1), (x, y, z, w). (x ', y', z ') :
w > 0, (x ', y', z ') = (x/w, y/w, z/w).
w = 0, (x ', y', z ') = (x ⋅ n, y ⋅ n, z ⋅ n). n , , x ' y' , . , (5px, 22px, 0px, 0) (5000px, 22000px, 0px) n = 1000, n (0,1px, 0,05px, 0px, 0). n . , (x ', y', z ') (x, y, z).
w < 0 , .
update: . . :