Jan

08-06-2003, 04:21 AM

Hi

Iīve searched the web for 2 days now, but i couldnīt find any tutorial on how to do real damned good specular lighting. Iīve only found those standard tutorials on how to achieve it in general.

What i want to do: I want each surface to have itīs own specular exponent. That means i donīt want to work with an exponent of 8 or 16 for every surface, as all demos iīve found do.

Maybe thatīs possible with a lookup table and texture shaders? If someone knows of an article or tutorial which explains this, i would be grateful.

And another thing: I want to be able to use spotlights, too. But then i have 1 3D-Attentuation-map, 1 bumpmap (+glossmap in alpha), 1 Norm. Cubemap for the half-vector, 1 Norm. Cubemap for some other vector (i think the lightvector) and 1 Cubemap for restricting the pointlight to a spotlight. That makes 5 textures. But i have only 4.

Therefore i thought of normalizing in the register combiners.

Has anyone done this with specular lighting? How are the results?

I once tried it for diffuse lighting + bump-mapping, but the results where very disappointing. But maybe for specular lighting itīs more useful?

Or is it possible to use only 1 Norm. Cubemap, but do 2 texture-accesses with texture-shaders?

I would really appreciate any good information you can give me.

Note that i already implemented (standard) per-pixel specular lighting once, but i wasnīt satisfied with itīs quality, therefore i am looking for improvements now.

Thanks,

Jan.

Iīve searched the web for 2 days now, but i couldnīt find any tutorial on how to do real damned good specular lighting. Iīve only found those standard tutorials on how to achieve it in general.

What i want to do: I want each surface to have itīs own specular exponent. That means i donīt want to work with an exponent of 8 or 16 for every surface, as all demos iīve found do.

Maybe thatīs possible with a lookup table and texture shaders? If someone knows of an article or tutorial which explains this, i would be grateful.

And another thing: I want to be able to use spotlights, too. But then i have 1 3D-Attentuation-map, 1 bumpmap (+glossmap in alpha), 1 Norm. Cubemap for the half-vector, 1 Norm. Cubemap for some other vector (i think the lightvector) and 1 Cubemap for restricting the pointlight to a spotlight. That makes 5 textures. But i have only 4.

Therefore i thought of normalizing in the register combiners.

Has anyone done this with specular lighting? How are the results?

I once tried it for diffuse lighting + bump-mapping, but the results where very disappointing. But maybe for specular lighting itīs more useful?

Or is it possible to use only 1 Norm. Cubemap, but do 2 texture-accesses with texture-shaders?

I would really appreciate any good information you can give me.

Note that i already implemented (standard) per-pixel specular lighting once, but i wasnīt satisfied with itīs quality, therefore i am looking for improvements now.

Thanks,

Jan.