AA and HDR Question

[TheRyuu]

A while back I asked about whether i should enable HDR or AA. I got mixed results but I can't really test it yet as my gaming rig (in sig) isn't built yet.

Anyway I have another question for you. I know you can't enable AA and HDR at the same time on Nvidias cards, but will it be possible in the future or is it a hardware limitation? Will a simple driver fix enable HDR+AA?

 

[nts]

Originally posted by: wizboy11
Anyway I have another question for you. I know you can't enable AA and HDR at the same time on Nvidias cards, but will it be possible in the future or is it a hardware limitation? Will a simple driver fix enable HDR+AA?

Some HDR modes (like Valves lost coast) will work but others using FP16 Render Targets will not (Farcry, SCCT, SS2, etc).

It is possible that with future hardware it will work but there is not going to be any driver fix for current hardware. Its a hardware limitation.

 

[TheRyuu]

Valves Lost Coast will let me use HDR+AA? I though that any HDR+AA would not be possible.

I currently have a 9800XT, will HDR work on that?

 

[Munky]

Let's clear up some things about HDR and AA. The traditional way to do HDR is by FP blending. This method only works on the geforce 6 series, 7 series, and Ati's new x1k series. This is how HDR is done in Farcry, and will not work on older cards without FP blending like the x800 or the 9800 cards. Currently only the new Ati cards - the x1k series are capable of doing FP HDR with AA, but will require a new patch for the games to enable support for this feature. The 6 and 7 series can not do AA with FP HDR, and no driver update will change that.

In Lost Coast, Valve developed a custom HDR solution using pixel shaders. This will work on any DX9 card, including the x800 and 9800 series, and also allows enabling AA. Older cards may not have the gpu power to run the game smothly with HDR enabled, but it does work, even with AA. But because Valve are doing HDR manually through pixel shaders it takes more work to develop, so dont expect other developers to do the same.