In an OpenGL program using four lights, I find that if I turn on GL_SEPARATE_SPECULAR_COLOR, only the specularities from the first two lights are visible.

I have verified that it is not that the image is saturated because even if I enable LIGHT2 or LIGHT3 alone, no specularity is visible. If I move LIGHT2 to LIGHT0 and enable it as the only light, I can see specularity.

Is this a bug in NVIDIA’s driver (30.82) or hardware? I have a GF4 Ti 4600.

oh, forget to say that I use simple texture mapping at the same time.


[This message has been edited by yang11 (edited 11-09-2002).]

It’s a bug, either in the driver or in your software. The separate specular is just a post texture fragment interpolation followed by a summation. Your using it implies some kind of texture use, that’s the whole point of the extension. If you had no texture it wouldn’t be needed.