Some new interesting information about valve's HDR implementation

[Galduta]

Sorry , a question

it has HDR + AA Call of Duty 2 for PC ?

HDR + AA in COD 2 in my Radeon?

thanks

 

[AlexV]

I think that the dudes making COD2 stated in an interview that they have no HDR in their engine.

 

[KimB]

I think that the dudes making COD2 stated in an interview that they have no HDR in their engine.

Good point.

There's HDR, and there's bloom. The two are related but HDR means so much more. HDR requires a higher-precision storage format for the framebuffer. Whether this is INT16 (very limited), MRT's (can be either limited or performance intensive), or FP16 (the ideal solution: should be the same performance as INT16 and MRT given an ideal implementation, with much better quality).

If you do bloom but not HDR, then this means that the eyes of the character through which you're viewing the game world will never adjust to his/her surroundings. For example, with good HDR, walking into a dimly-lit cave would at first appear dark, then you'd be able to make out detail, but the colors would be shifted slightly to the blue and very little color would be visible. Without HDR, the dimly-lit cave will just be hard to see anything in. You could turn the gamma way up to see something, but then you'd have horrible banding.

 

[Galduta]

Well, a pretty Bloom effect video 6 mb

 

[Xmas]

nVidia hardware doesn't support 16-bit integer rendertargets.

Neither does current ATI hardware support MSAA with 16-bit integer rendertargets.
They don't use 16bpc rendertargets.

 

[KimB]

Neither does current ATI hardware support MSAA with 16-bit integer rendertargets.
They don't use 16bpc rendertargets.

Hrm, then either I must have misread Anandtech, or Anandtech got it wrong. I guess it's back to the MRT rendertarget idea that we talked about earlier?

 

[vember]

MRT is incompatible with MSAA in DX9.

 

[KimB]

MRT is incompatible with MSAA in DX9.

Well, MRT can always be emulated by just rendering multiple times, but the performance hit would be pretty incredible, so I'm pretty sure Valve isn't doing this.

Anyway, I was told that one could use MRT with MSAA....so who's got evidence?

 

[Hyp-X]

nVidia hardware doesn't support 16-bit integer rendertargets.

Yes they do since the 77.xx drivers.

 

[vember]

Anyway, I was told that one could use MRT with MSAA....so who's got evidence?

The DX9 documentation (august 2005 update) clearly states you can't, but it's not necessarily a hardware limitation.

I haven't seen anything indicating that they're not just using a single 8-bit/channel rendertarget. (with an exposure scaling in every pixel-shader rendering to it and a bloom applied afterwards)