Programmable Vertices


Any one tried ARB vertex_program and discovered that it performs more than 50% slower than fixed TnL pipeline, or faster by 3 frames per second than it is software counterpart?

I found ths on my GeForce 2 MX 400
Dirver 1.4.1


Officially, ARB_VERTEX_PROGRAM are not on the geForce2(Mx,GTS).

I don’t know how you can parform arb_vertex_program on geForce2 mx?!?!?

The extension is present but only supported in software on pre-Geforce 3 and the Geforce 4 mx.


Thanks, i didn’t know this.

If it’s software, it’s normal that it’s slow.

Thanks for the information.
But how in the hell Direct3D vertex shading works as it’s implemented in HW. This means that my card has a special unit for vertex instructions, and I believe it’s the same VPU used for OpenGL, isn’t it?
Then what is reason for implementing OpenGL VPs in software?

It’s also done on software in D3D. From what i remember, there is a “mixed vertex processing” mode, which allows hardware T&L, but to switch to software vertex shading if the hardware doesn’t support it. There’s no miracles.