View Full Version : Specular reflectance with textures.

03-09-2001, 03:05 PM
I can't seem to find a straight answer for specular reflectance using textures...I can get it to work without textures...but what is the procedure to add it to a polygon that has a texture onj it?

I'm trying to get a little sparkle to an enviornment maped water surface...

03-09-2001, 04:00 PM
I hope this is the answer you're looking for:

Normally, specular color is applied to a poly before texturing. So, texturing will basically, "cover up" specular highlights. (If you look at the big funky chart included in the OpenGL 1.2 Reference, you can see this order of operations).

You can use the EXT_separate_specular_color extension so the specular highlights will show through your texture.

Take a look at this demo in the ATI Radeon SDK: http://www.ati.com/na/pages/resource_cen...teSpecular.html (http://www.ati.com/na/pages/resource_centre/dev_rel/sdk/RadeonSDK/Html/Samples/OpenGL/RadeonSeparateSpecular.html)

03-09-2001, 08:26 PM
Thanks! That's exactly what I needed. This is a first for me using extensions. I wonder if this extension is available on other cards (for compatability)?

Thanks again!

03-10-2001, 04:57 AM
I think most cards have it.