   Cg shader question (allowing opengl lighting)
  Here's my problem: I am currently working on adding shaders to my landscape rendering code. I programmed a shader that combines multiple textures and alpha maps for nice texture splatting effects. But the problem is that because the fragment shader took over, the lighting that used to work isn't applied any more. I guess that's because I don't handle the lighting in my shader.So now I have 2 questions:1. (how) do I have to change my shader to allow OpenGL lighting to work again?2. Is this problem going to occur every time I want to use an OpenGL effect like blending, lighting, whatever when I use a shader on that geometry?   
  1. you can't, not directly. Your code totally replaces all fixed function operations so you have to perform the lighting equations yourself. In GLSL you have access to the values you give the fixed function lights, I don't know if Cg has the same thing.2. Your code replaces all vertex and fragment operations, so yes you will hit this 'problem'. Alpha blending in the framebuffer isn't effected however.   ;  ok thanks, I've started working on implementing my own basic lighting... working quite well. Glad I took a math course this year :)   