I'm working on a game engine, and I want to be able to draw a billboarded (i.e. rectangular to the screen) quad with the center-bottom of the quad being determined by a single point. Unfortunately, I have basically no idea how to do this myself, and I haven't had much luck deciphering some of the other tutorials and/or converting them to OpenTK/VB.NET.
side note: I'd tag this "OpenTK" but the tag apparently doesn't exist.