Not logged in, Join Here! or Log In Below:  
News Articles Search    

 Home / 3D Theory & Graphics / Texmapping coords and reading U V correctly Account Manager
Archive Notice: This thread is old and no longer active. It is here for reference purposes. This thread was created on an older version of the flipcode forums, before the site closed in 2005. Please keep that in mind as you view this thread, as many of the topics and opinions may be outdated.
John Shield

June 27, 1999, 02:01 PM

Hi dude/tte/s!

I was wondering about texmapping coords that get the correct texel.
I define 3 vectors which are the coords for each point.


p0. p1.

p3. p2.

i use p0, p1 - p0 and p3-p0 for my cross products
to make 3 vectors

then i take the dot product of each vector and the i,j screen coords

to get the U V texel refered by the screen pixel.

here are my questions :

is it right to take the exact 3d vertices for the vectors?

how do i ensure the read U V is true? (not negative)

should the middle of the screen be 159.5,99.5 or 160,100 in rasterization???
(for this method of texmapping)

I hope someone can help.

I will be offline start of July so if you got an answer after that
send it to


This thread contains 1 message.
Hosting by Solid Eight Studios, maker of PhotoTangler Collage Maker.