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views:

27

answers:

3

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

+1  A: 

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.)

Thanatos
Ok thanks, I was hoping to avoid the calculations :-p
Milo
A: 

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.

Malte Clasen
Alright, thanks (gets out scientific calculator and pushes sin and cos buttons)
Milo
A: 

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.

SigTerm