Hi. I'm a very new beginner to OpenGL, and I was wondering how to use glLoadMatrix()with glFrustum() to use real coordinates to set up the screen so my cubes stay cubes instead of changing to rectangles. I want to do this by having my coordinate system (0,0,0)-(640,480,800).

I also want to be able to convert the depth of a point -lets say (40, 40, 15)- to a 2D coordinate -like that point being (50, 50)-, and I want a 3D coordinate from a 2D coordinate at a specific z value, like to find the max (x,y,z) that still is visable on the screen - (640,480).

I'm pretty desprate to using a forum to find out how this is done, so any websites you can find will be very useful. The biggest thing that troubles me is setting up the coordinate system. The other things I know well enough. I have LaMothe OpenGL book if you know of anything in there that could be of help. Sorry for being such a beginner and about not wanting to convert my programming to OpenGL's native coordinate system.