Billboarding with vertex program?

I am computing the veritces of a quad in such a way that the quad will always face the camera.
Would it be possible to use a vertex program for this?

As you probably assume I know nothing about vertex programs, so if it is possible, a detailed description would be very appreciated!
Thanks for your time.

Hmmm yes, thanks.
So you don’t know if it possible?

Of course it’s possible, because all you need is your matrix, that’s all.

[This message has been edited by M/\dm/
(edited 12-21-2002).]

Do you suppose it will be faster?
I don’t want to be a pest, but my idea was that if I knew that the vertex program-approach would not really increase my fps, than I would focus on different parts of the program rather than learning Cg now without any real use for me (yet).
Thanks for the reply

CG is prety easy for beginning & results are whole lot better. Only minus is that you need T&L card. Not sure about performace yet, although, a lot of work is moved to GPU instead of CPU, so - parallel performance.

It just came to me: Does the GeForce2 support vertex programs at all?

I can’t download Cg at the moment anyway, server is strange…

[This message has been edited by B_old (edited 12-22-2002).]

Works on my GF2GTS, I even can run NV30 demos with emu. And current non-beta compiler should support fr programs too.
Yes there is serious problems with server, unfortunately as often

You dont need cg for this, just use ARB_vertex_program. GF2 supports it.

Old GLman

Just downloaded CG final. There are some pure OGL demos. CG is easier & have optimizing compiler to make all the stuff faster (I hope so, havn’t checked out).

Well thanks for the replys.
I see what I can manage. It seems to be possible as you say.