Hey GameDev, I'm finally learning shaders! I just read the NeHe tutorial on glsl, and then watched the following excellent introduction video:
So I'm just about ready to dive in... only, I'm realizing now that my reason for learning shaders might not even apply. I wanted to apply an effect to all points drawn on the level, but not the player (a gradient from bottom to top based on position.y % 10, see here: http://www.galigogames.com/images/cubior/cubior3.png ). The player would be on a different plane for this calculation, so when he/she moved, the gradient stayed relative to the player's cube - but all other gradients would be static.
When I read and watched the tutorials, it looked like shaders applied universally. I'm pretty sure still that it's possible to do y position based coloring/brightness, but can I have shaders apply only to certain polygons, and not others?