Inquirer Gossip:- NV35 supports PS 3

[Sage]

Centroid sampling is already in DX9, but it currently requires PS 3.0 compatibility even though it's technically possible to do without PS3.0 (ie R3x0 series) but DirectX doesn't allow that. Also, it is possible for any PS2.0 card to perform centroid sampling in the pixel shaders, here's a quote of Gabe Newell I saw on fireingsquad:

There's a different trick you can use with hardware, such as NVIDIA's, that doesn't support centroid sampling. Basically you trade off some pixel shader bandwidth to clamp the texture coordinates so that you don't sample texels outside of that polygon's lightmap sub-rect.

Ironic that, in order for the DX9 chip series that doesnt support Centroid sampling, it relys on the chips weakest part to emmulate it...

 

[Ostsol]

It's not exactly performing centroid sampling at all or even emulating it. It's merely replacing it with another method that also happens to prevent textures from being sampled outside of a specific region.

 

[Sage]

perhaps I should say emmulate the effect...

 

[THe_KELRaTH]

So what we really have is an Nvidia bod claiming the NV35 supports PS3 but when tested it fails in hardware, whereas ATI supports and will be using Centroid sampling which is part of the PS3 spec.

Sounds to me that it's ATI thats more PS3 compliant just now

 

[Xmas]

Sounds to me that it's ATI thats more PS3 compliant just now

You shouldn't forget arbitrary swizzle, gradient instructions, predication, dependent read limit...

 

[Arun]

Just spoke with Fudo about it...

My understanding of the matter would be nVidia did a PS3.0. driver for the NV35 & NV36, but that they would fail at compile if it includes some of the stuff they can't do. Seems boring to me. I can't promise I'm right here, but it seems obvious they don't have a miracle approach to get PS3.0. compliancy suddently.


Uttar

 

[Luminescent]

R300 can also do arbitrary swizzle.

 

[FUDie]

R300 can also do arbitrary swizzle.

In the vertex shader only. It's not a PS 2.0 requirement to be able to do arbitrary swizzle.

-FUDie

 

[DemoCoder]

But it is in PS3.0.

 

[T2k]

On another note; isn't Centroid sampling meant to be part of DX9.1/PS3 featureset.

There's no such thing as dx9.1 and it's not sure it ever will be.

Exactly. I reiterate this all the time.

 

[WaltC]

Yes, I would think a claim of "nV3x would have ps3.0 if it wasn't broken in the hardware" would be a bit dubious...