Valve's High Dynamic Range Explored
by Josh Venning on September 30, 2005 12:05 AM EST- Posted in
- GPUs
Introduction
Now is an interesting time for PC gaming. With the release of NVIDIA's 7800 series as well as the upcoming ATI x1000 series graphics cards, the potential for graphics in games is only just starting to be realized. Games like F.E.A.R, Call of Duty 2, and Age of Empires 3 promise to take PC gaming to a new level graphically, and frankly, we couldn't be happier about it. We seem to have a similar situation right now of when ATI's RADEON 9700 series launched, and the new hardware allowed game developers the freedom to experiment with new ideas; therefore, creating a new generation of games. One particular graphics engine that has had an important impact for developers lately is Half life 2's Source engine, and though it has been around for a while now, the developers have recently decided to give the engine a bit of a face-lift, metaphorically speaking.
That's right, Valve has updated their source engine to enable something called High Dynamic Range, and the first two applications to implement this are Day of Defeat (a popular Half life 2 mod) and the upcoming new level for Half life 2: the Lost Coast. High dynamic range is basically a more realistic way to implement lighting in a three-dimensional world. With HDR, light sources will appear brighter, and other effects like blooming are possible. HDR, along with other things like auto-exposure, take lighting to a new level, further enhancing the realism of a virtual world. To give you a better idea of the concept behind HDR, here is a quote from Paul Debevec:
Now is an interesting time for PC gaming. With the release of NVIDIA's 7800 series as well as the upcoming ATI x1000 series graphics cards, the potential for graphics in games is only just starting to be realized. Games like F.E.A.R, Call of Duty 2, and Age of Empires 3 promise to take PC gaming to a new level graphically, and frankly, we couldn't be happier about it. We seem to have a similar situation right now of when ATI's RADEON 9700 series launched, and the new hardware allowed game developers the freedom to experiment with new ideas; therefore, creating a new generation of games. One particular graphics engine that has had an important impact for developers lately is Half life 2's Source engine, and though it has been around for a while now, the developers have recently decided to give the engine a bit of a face-lift, metaphorically speaking.
That's right, Valve has updated their source engine to enable something called High Dynamic Range, and the first two applications to implement this are Day of Defeat (a popular Half life 2 mod) and the upcoming new level for Half life 2: the Lost Coast. High dynamic range is basically a more realistic way to implement lighting in a three-dimensional world. With HDR, light sources will appear brighter, and other effects like blooming are possible. HDR, along with other things like auto-exposure, take lighting to a new level, further enhancing the realism of a virtual world. To give you a better idea of the concept behind HDR, here is a quote from Paul Debevec:
"The 'dynamic range' of a scene is the contrast ratio between its brightest and darkest parts. A plate of evenly-lit mashed potatoes outside on a cloudy day is low-dynamic range. The interior of an ornate cathedral with light streaming in through its stained-glass windows is high dynamic range. In fact, any scene in which the light sources can be seen directly is high dynamic range."Obviously, one of the first things that we were concerned about regarding this upgrade was how this would affect performance. We weren't sure quite what to expect, but we did some testing on multiple ATI and NVIDIA graphics cards, and we'll take a look at the results later on. First, let's go a bit more in-depth into the technology.
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eastvillager - Monday, October 3, 2005 - link
Screenshots don't do it justice, nor does 'trying' it for 5 minutes, deciding you don't like it and then going back to your old config. It adds considerably to the experience, for me at least.Marsumane - Sunday, October 2, 2005 - link
Im not so sure I agree that the NV cards are not as good at implementing this engine's HDR effects due to the fact that the NV cards are all one of two extremes. They are either the highest end cards which crush the entire ati lineup and dont provide a good comparison, or they are the lowest-tier card in the roundup with no real direct competition. I mean just look at the memory bandwidth of the 6600gt as well as the pixel pipelines and ull find that it has no real comparison to the ati cards benched. Furthermore, I dont see how the ATI cards have anything to compare to either. It seems as if the top NV card had the least impact from implementing HDR and it just scaled down the list fairly evenly. Maybe the conclusion was made based upon the numbers of cards not posted, but from my perception, based on reading the numbers on here, I'm not seeing any real reason to state that NV cards do worse than ATI cards in this comparison. Furthermore, look at the x800 from bloom to full HDR. The 6600gt had less of a percentage hit as compared to the x800. Maybe I missed something, but does anyone else see this? Please correct me if im wrong.gamara - Tuesday, October 4, 2005 - link
I caught that too. The GTX dropped 2.5 FPS from none to full. The x850 XT dropped 15.8. For those that like percentages, the NVidia dropped 3.5% while the ATI dropped 22.3%. How exactly is that better? I like how the GT went from second to last with no HDR to second best with full. I will concede the 6600 GT dropped over 50% with the full effect, but when FSAA first hit the scene the thought of running a low-mid range with AA was OBSURD.islandtechengineers - Sunday, October 2, 2005 - link
i know why... factors factors factors..... anyway its still not nice to only release if with DOD and the lost coast..... to bad if couldnt be released for all :-{ even as a update which I'm sure will arrive..Busithoth - Saturday, October 1, 2005 - link
well, I'm running a 2405 with an x800xt, and HDR made the difference between smooth as butter and less than that. I liked the effect, but the fast pace of things in DoD made it really annoying to me more than anything else. Given time, I can get used to it, of course, but I'd rather be in single-player doing so (come on lost coast), then I can try my hand at MP again.I can't understand the argument that it's an aid to players, though.
More realistic, I'll grant that. but how exactly does it help anyone but campers, I don't know. Besides the fact that people can just turn it off, it's an act of faith to assume that someone's gonna be blinded coming around a corner. (as I was multiple times when it was still enabled)
altogether though, HDR on, I thought this game was bliss for the eyes.
Frackal - Friday, September 30, 2005 - link
Why do computer users bitch so muchI love the HDR, it does look more realistic and moreover BF2 looks crappy after playing DOD-S. BF2 was my fav. game until DOD-S, now its a tough call because BF2's gameplay is better but it doesn't look that great anymore.
HDR is the future
OvErHeAtInG - Saturday, October 1, 2005 - link
Yes. Most of the people complaining about HDR haven't even tried it, it seems. See Wilson's post above, you have to see it in motion. Frankly the screenshots don't look anything like the game in motion. Has anyone here played GT4 for the PS2? They implemented some sort of advanced light thingies like this to great effect. The whole point is how something (wet road surface at sunrise) would look totally different depending on the angle you're looking at it from; blinding white one second, black the next, just like in real life.Has anyone else tried HL2 after they added HDR to some of the maps? Looks good. And like they said *if you read up on it*, this is really a partial implementation of HDR, worked into the source engine. Of course it's really only worth it if you have a high-end videocard, otherwise you'll have to disable AA in order to get playable frames. In a very-aliased game like HL2, it's a tough call which I'd rather have :)
coomar - Saturday, October 1, 2005 - link
with a 6800gt, i was playing everything high at 1280x1024 with 2x aa/8af i think with hdr ongravy - Friday, September 30, 2005 - link
the 6600GT is obviously going to be limited, but why put a 6600GT up with X800's and the likes of 7800's ??!!might as well have thrown in a 9800XT to compare with the 6600GT, and then a 6800GT to compare with the X800's
i hope to see a follow up to this with these cards as well as the upcoming X1800's and X1600's, a nice well rounded comparison to see how both players are fairing with the new technology
perhaps a Lost Coast review will be just that as it will likely be more demanding than DOD:S ??
thanks for a nice read
ViperV990 - Friday, September 30, 2005 - link
What is the point of all these fancy lights if there are no shadows? I am talking about the boat and the tank traps in the screenshots.