Original Post
I'm trying to figure out to "collapse" the depth of a 3D object. In other words, I draw something in 3D, and then I want it to become a flat 2D object (although if I don't rotate it or look at it from a different angle, it still looks the same to me). The reason for that is that I want to "merge" an object that I draw with a frame captured from video (which is basically a texture mapped onto a rectangle). If the object remains in 3D, then placing them along the same z plane causes some parts of the object to be hidden behind the video frame, which isn't what I want. Anyways, hopefully you get the idea. I looked into glMultMatrix, but I don't understand how the projection matrix works... I'm not even sure if that's what I'm really looking for. Is there any "simple" way of doing this?
