Hi everybody. I'm struggling pretty hard with this, and I need some help here. OK, I'm actually totally stuck. I'm trying to teach myself OpenGL to enhance some graphics in some applications we have here at the office, and I just can't find any help with this problem.

Anyway, I'm trying to create a basic model viewer. I decided to go with the ArcBall type of interface because of how nicely it ends up working. I actually got the arcball interface working great. The problem I have is with translation.

What I would like to try to do is to translate my model in a plane parallel to the screen, regardless of it's rotation, all while keeping the center of rotation in the center of the screen.

This seems like it should be rudimentary at best, but no combination of translations and rotations seems to do the trick. I can get center-screen rotation or screen-plane translation to be mutually exclusive, but putting it together is driving me crazy. I never took a math modeling course, or a graphics course when I was in school, so all of this is totally beyond me...even if I knew where to start, I'd still be out of luck.

Anyway, I've gotten the arcball working using code samples from the internet. If I posted some code, would somebody be willing to take a look and help me work through it, or at least tell me what I need to do?