Silvan · Engine Programmer

Yeah, I talked to our developer who works on that. And right now, other priorities took over that task, so it's on hold right now. He's doing home office a lot of the time right now, and he has a super fancy HDR monitor in the office. Once he comes back, which is hopefully soon, and we're even going to move into the new office soon, which I'm super excited about, hopefully then he can take it on and finish it, because I'm very much interested in that as well. For everyone who doesn't know what HDR is, it means high dynamic range. Basically, it means colors from a monitor can be much brighter and more vivid than on a standard monitor like everyone's used to. And rendering, physically based rendering, which most engines do these days, already renders in HDR. And then as a post-process effect, all those colors get compressed into what we call low dynamic range, LDR. And that's what goes to your monitor, after some other fancy post-processing effects; gamma needs to be applied, but that's a story for something else.

Ali Brown · Director of Graphics Engineering

So a bunch of support, I think, has been done. I think the last I looked, the tasks that were remaining to make it fully finished were three of them. So we have color processing, which is something the artists apply where they want to set the mood of a scene, like a blue-tinted sky. And they don't tint the actual sky when they want to achieve a mood. They render the sky physically accurate, and then, if you imagine, a bad example, every nighttime scene in a film is filmed in daylight and then they just make it blue. That's an exaggeration, but that's the approach. So sometimes the artists use these things, usually quite subtly, but that process is currently mapping one low dynamic range color into another low dynamic range color. The process becomes a bit more complicated when you're dealing with high dynamic range colors. When they say they want to turn a white sky to blue or a blue sky to white, it gets more complicated. There's now millions of shades of white, millions of shades of blue. Did you just mean the very bright blues or the ultra bright blues or the extremely bright blues? So that process needs to be changed, and it involves changing the art pipeline a little bit and how they author the color correction. And the two other issues: we have what we call the game post effects, which are not the critical rendering ones like color correction or our lighting and blurs and things like this, but like when you've been shot, blood appears on the screen, or you're blacking out. These types of effects all run in low dynamic range, so they all need to convert to high dynamic range so they don't lose quality. Otherwise, they'll appear very dull if we don't do that. And then the final one is the more open-ended one. When people say this game has a good HDR implementation and this game has a bad one, like Silvan said, we already render the game in HDR. The problem is even the HDR monitor, it's high, but it's not infinite dynamic range. If we had infinite dynamic range, we'd just give you the image we rendered, but that's not the case. What you have to do is query the monitor, find out what range it's got, and make a best guess of how bright you think you should render the image and how you should color correct the image, and then probably also give some sliders for the user so they can tweak it themselves. That can be a hugely subjective point of view, and like I say, different games get either praised or beaten for how amazing or terrible their HDR implementation is. But it's really just that last part in the pipeline that people get upset over. So we need to just balance that and make sure we expose the right knobs and tweaks so everyone can get the image they want on their monitor.

Jared Huckaby · Host, Community

It doesn't help that there's probably a dozen HDR standards, or a half dozen HDR standards.

Ali Brown · Director of Graphics Engineering

Yeah. Lots of color spaces, lots of different ranges, different ways of interpreting things. It's a bit of a minefield.