Re: [Algorithms] Normal mapping error - not sure if it's a generation error, or a rendering error

[Christian S. <chr...@bt...>]

Hi!

Whatever tool you use (ATI's, ORB, or Kaldera, etc, etc) the most
important thing (as said by other people) is that your tangent basis are
correct.

While making ORB and including normal mapping in my engine I tried a bunch
of algorithms and find that many are flawed, including ones presented by
nvidia and microsoft (in tutorials for example).
The one that works in all cases (under the restrictions
mentinioned earlier like [0,1] range, etc) is the one by Eric Lengyel in his
book
Mathematics for 3D game programming and CG,
http://www.terathon.com/books/mathgames2.html

With his permission I include a .pdf with C-code that you can copy and paste
into your engine. The pdf lies in the ORB.zip at
/docs/orb_tangentvectors.pdf

http://www.soclab.bth.se/practices/orb.html
(direct download): http://www.soclab.bth.se/practices/orb/orb.zip

You can also read Eric's post in the Opengl forum
http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/011349.html

From what I've heard Kaldera is the best, but it does cost some moneys...

Soon nvidia will release Melody, we'll see how good that one is, they've
been
working on it quite long now, tried an alpha a year ago.

good luck

chris