Another topic about vertex programs

[richardve]

No, I'm not going to ask when the official drivers are going to be released with support for vertex programs.

I only want to know why Direct3D's vertex shaders are accelerated and vertex programs not.

Do they ever become accelerated for the GeForce2 (MX/GTS/Ultra) or do I have to wait for the NV20?

[Eric]

Originally posted by richardve:
No, I'm not going to ask when the official drivers are going to be released with support for vertex programs.

You should... It costs nothing to ask and, one day, they might answer !

Regards.

Eric

P.S.: I have no clue regarding your question... Are you sure DX8 vertex shaders are HW accelerated ????

[richardve]

"You should... It costs nothing to ask and, one day, they might answer ! "

I'll just wait because they're never going to answer that question


"I have no clue regarding your question... Are you sure DX8 vertex shaders are HW accelerated ????"

Yes, I'm sure about that, there's an option for switching to software processing in the nVIDIA Effectsbrowser.

So if it's possible with D3D it should also be possible with OGL??

[Eric]

Originally posted by richardve:
So if it's possible with D3D it should also be possible with OGL??

I guess so... It is not very clear (for me !) what a GeForce/GeForce2 can actually do in hardware regarding vertex programs/shaders.... I must say I am not sure at all whether the program itself can be run in HW even on a GeForce2... In the NVEffects Browser, isn't it the rasterization that can be HW/SW ????

Regards.

Eric

[davepermen]

vertexshaders arent hardware on current hardware in dx

[richardve]

"vertexshaders arent hardware on current hardware in dx"

From what I understood is that the VERTEX shaders are in hardware and PIXEL shaders not...
(well, only on a GeForce or better)


"In the NVEffects Browser, isn't it the rasterization that can be HW/SW ????"
I'm not really sure but I assumed that it's meant for switching between HW/SW processing of vertex shaders.
Are there some people here who can tell me if this is true?

And register combiners, are they processed in HW?
(I think they are..)

Mmm, so many questions...

[Eric]

Originally posted by richardve:
From what I understood is that the VERTEX shaders are in hardware and PIXEL shaders not...

I cannot tell for sure but I really do not think that GeForce was designed with vertex shaders in mind...

Originally posted by richardve:
Are there some people here who can tell me if this is true?

I am sure Matt, Cass or Spit will answer you...

Originally posted by richardve:
And register combiners, are they processed in HW?

Yes, they are !

Let's wait for an answer from the guys mentioned above !

Regards.

Eric


[This message has been edited by Eric (edited 02-09-2001).]

[davepermen]

hm, i dont know where.. eigher on nvidia.com or in the helpfiles of dx8 or somewhere on the microsoft page.. but i read on an official page that no current gpu supports any vertex- or pixelshaders, but in fact, when you disable hwtnl, you get the same speed as you have at software vertexshaders, cause it does nearly the same.. just pixelshaders are (logically) slow in software.. its like raytracing in software..and this is on big resolutions just sloooooooooooooooooow

[richardve]

How do you know that it's the same speed?
I can't see a frame counter in the Effect Browser and the models are not that big...

There's an example in the DX8 SDK (something with a skinned character) wich is done using vertex shaders.
When I switch to SW processing in that demo I'm getting 15 FPS less than with HW processing...
That's another reason why I think that vertex shaders are HW accelerated with D3D8.

And I also know that pixel shading is sloooooow


[This message has been edited by richardve (edited 02-09-2001).]

[davepermen]

i dont know what is done all in software, but they could not implement the whole shaders into hardware yet, cause the hardware is just not made for it.. and as i know, this is not just for pshaders, but for vshaders, too..