I have a problem. I was working on a game, and I created a plane, xrotated it -90 (to make it flat), and textured it. As I yrotate the camera, the plane appears to get dark and textureless, then light and textured. This happens gradually, and looks similar to the effect when looking at the sky through a polarization filter. I cannot have this happening in my game, and was wondering if anyone else has seen this happening and/or has a solution. Thanks!

PS: I have attached a program with this plane. Use the left and right arrow keys to rotate the camera, and see the changes in the polarization.

Lighting doesn't tend to like few polygons. To get good lighting, you need a few hundred polygons, otherwise it tends to screw up a little. That's why you dont get this problem with matrixes.

so...should I make it a matrix? is there a way to correct this but still use the plain (for speed's sake)?

Well unless you completelly remove lighting from it, I can't think of anything. Sorry.

Or you could just make a plain with a modeller and up the poly count.

Or you can think about using per pixel lighting if you have a shader compatible card. I think its a better option as designing a level around the lights is more of a pain then anything. I think lightmapping and per-pixel lighting together are a pretty strong combo. Anyways those solutions will also work to just giving you some other options.