I'm trying to run GLSL with a vertex shader only and bypass the fragment shader. I would like to manipulate the vertices and let the fixed pipeline handle the lighting. For what I am trying to do, I don't want to bother with fog/lighting. Is this possible with GLSL? I can do it with nVIDIA Cg. I have a basic understanding of GLSL and I understand that I am required to output the position. And, my video card supports all of the necessary extensions. When my vertex shader is only... gl_Position = ftransform(); ...I get no display of my geometry, unless I also have a fragment shader. Then I see the textured geometry. I would expect to at least see the geometry with only a vertex shader, even if it's not lit correctly. 1) Is it possible to only use a vertex shader and bypass the fragment shader? 2) Am I missing some outputs in my vertex shader since I see nothing at all? Thanks for any help.

You have the option to specify just a vertex shader, just a fragment shader, or both of them. If you specify just a vertex shader, the fixed function fragment shader is used, which expects that you also set the other parameters (like the vertex color as would have been computed by the fixed function vertex shader).

Thanks for the input.

I found out that I was missing the following.

gl_TexCoord[0] = gl_TextureMatrix[0] * gl_MultiTexCoord0;
gl_FrontColor = gl_Color;

Actually the geometry only displayed when I included the gl_TexCoord part.