Alpha Test w/Lighting Problem

I’m having problems with the Alpha Test when I enable Lighting.
I load a bitmap and add an alpha channel, setting any black pixel to an alpha value of 0, and anything else to 255. I then call glAlphaFunc(GL_GREATER, 0) and everything that is black is not drawn. But when I enable lighting, I can’t see anything when it starts rendering.

Does OpenGL lighting have some affect on the pixel alpha value before it is tested with the AlphaFunc? Is there a way to ignore alpha fragments with alpha 0, and THEN do lighting?

Do you see anything rendered if you simply do not turn Alpha test on? ie. Are you sure Alpha test is the problem and not your lighting setup?

it must be lighting setup problem. if your diffuse material color has alpha==0.0 and the ambient parameter of each light have alpha==0.0, then the computed color for the vertex will have alpha==0.0

Yep, it was the fact that I wasn’t even passing an alpha value for the diffuse and ambient material properties of the object. I just added in a 1 for the alphas for materials and 1 for the light diffuse and ambient and I see everything just fine. Thanks a lot.