hi i wrote a linear texture mapping routine. now i read about perspective correct texture mapping. i just want to ask if i got it right: 1. linear texture mapping is based on the *wrong* fact that the amount to be added to the z value is contant. 2. perspective correct texture mapping is based on the fact the the amount to be added to the value of 1/z is contant. please just say yes, or no+explanation. ah, btw - what''s affine texure mapping? is it like the perspective correct tmapping? thanks, oren.

Yes, correct.

Affine texture mapping is just another name for linear texture mapping.

Good luck,
-mother

no, unfortunately that''s wrong.

1. linear mapping assumes that the values added to u and v are constant.

2. perspective mapping is based on the fact that the values added to z, u/z and v/z are constant.

in your routine, you interpolate z, u/z (uz), v/z (vz) (all get constant values added) and the real texel for each pixel is
u = uz * z and
v = vz * z

this is NOT
u = (u/z) * z and
v = (v/z) * z

okay?
Coder1000