I need somebody that can either help explain to me the operation of a 3D engine (no more advanced than the one used in Hexen/Strife), or somebody who is willing to code one with me for my game. I've got the rest of the code squared away, but I cannot grasp the 3D concept for the life of me. I've been told it uses sin/cos, but I've never used those before and don't know what they do or what value they hold. Once again, I'm not looking for information on or help coding some new "Unreal" or "Quake" engine. A simple Doom engine would be perfect. I appreciate any help that anybody can offer. Oh, and I am posting this in the Games Programming messageboard as well, since it's a game engine that I am looking for.