get resulting verticies from a gltransformation?

Question

I have some verticies and then I apply a glrotate(). I'd want to now what my verticies became after this transformation. How could I do this?

Thanks

Answer 1

I don't think there's any other way other than calling glGet with GL_MODELVIEW_MATRIX and doing the resulting transform yourself. (Or calculating the same transformation matrix yourself, and apply it to your point.)

Answer 2

There is a way to do this, but you probably don't want to go there. There is the so-called transform feedback which stores processed vertices in buffer objects. You can read back these and get your vertices. This might be useful if you have a huge amount of vertices, but my bet is that you're better of transforming the vertices on your own, as Thanatos proposed.

Answer 3

Again?

You can't do that. There is a feedback buffer, but that's not what you are looking for. Read my previous explanation for details.