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andreasMank
06-28-2004, 01:53 AM
i'm using nvidias brdf seperator to create d and h textures for realtime brdf rendering .. i'm generating the brdf value and everything is really fine .. but what do i have to do with the brdf value ?? how to multiplicate with my base texture values ???

.. and having a look in my two brdf textures i'm wondering about their looking .. why are the d and h textures colored ??? i thought the brdf value discribes the rate of reflection .. do i have to interprate my brdf value seperate ??

plasmonster
06-28-2004, 10:53 AM
The papers here describe the entire process in great detail.

http://developer.nvidia.com/object/BRDFbased_Lighting.html

Both your G and H textures encode color (RGB triples). The separation is required because currently you can't encode a 4D function directly, so instead you have two 2D functions ( the cube map setup for this is nice).

Anyway, the paper goes on to describe the basic combiner setup like this

Color = Scale * G * H * incomingFragColor

You can do this with texture combiners, or in a fragment program. And those texture coordinate calculations would be a snap in a vertex program.

I didn't have a chance to look at the demo.