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Corners Don't Look Like That: Regarding Screenspace Ambient Occlusion (2012)

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Re: Corners Don't Look Like That: Regarding Screenspace Ambient Occlusion (2012)

#41

Post by mrandish »

aaroninsf wrote: post #35
Geee wrote: post #30

Earlier quoted context omitted.

I don't think this is true at all. I've been experimenting with a physical sky / atmosphere modeling, and it really seems that the most physically accurate sky is the most beautiful. I think this applies more generally to all light and shadows, and all natural effects which people perceive as beautiful, and at the same time difficult / expensive to recreate on a computer.

I would suggest that both are true! It's common for games to have an intentional designed aesthetic which uses cultural and social and graphical "languages" to create specific emotional impacts and effects. The lower the budget the more this is leaned into for expedient reasons but that in turn creates genre expectations! Low-poly and 8-bit are fine examples of what were once a product of technical limitations becomi…

> It's common for games to have an intentional designed aesthetic ... to create specific emotional impacts and effects.

And before games this was true of movies and before that photos and paintings. A master cinematographer can spend hours lighting a shot that will later be praised for its 'gritty realism' :-).

Re: Corners Don't Look Like That: Regarding Screenspace Ambient Occlusion (2012)

#42

Post by Terr_ »

astrobe_ wrote: post #39
overgard wrote: post #7

I agree with his overall point, but I would point out: realism is not usually the point, the point is to look good. The problem with realism is once you get past "wow the computer can do that now", it's not very interesting -- most of reality is pretty dull looking!

Tangential, but sometimes real images can also seem unreal. I remember seeing a photo of Earth and the Moon with the Moon on the foreground that looked like a bad CGI. But it was actually a photograph taken by a space probe. Or, one can think about those photos of the Apollo lunar module that looked "wrong" (and probably helped some conspiracy theories spread), but were obviously correct - just there's no atmosphere…

Condensed rant: Humans are blind to the most common gasses on our atmosphere (N2, O2) and sometimes have difficulty perceiving its most common liquid (H2O). This is sensible, since otherwise we'd be helplessly wandering through "visible" fog to fall off cliffs or be eaten by giant carnivorous bats. Our "colors" are mostly a quirk of where we're from.

Now suppose some aliens arrived at our planet and said: "Wow, your planet is the most-boring we've ever seen, it's all just one N2-colored ball." We'd be a little offended! Clearly, the dumb aliens are looking at it wrong!

Flip that in reverse, and we have an artistic obligation to choose "good colors" for planets that maximizes their interesting features. We already did it for surface-views on Earth.

Re: Corners Don't Look Like That: Regarding Screenspace Ambient Occlusion (2012)

#43

Post by ambicapter »

Geee wrote: post #30
overgard wrote: post #7

I agree with his overall point, but I would point out: realism is not usually the point, the point is to look good. The problem with realism is once you get past "wow the computer can do that now", it's not very interesting -- most of reality is pretty dull looking!

I don't think this is true at all. I've been experimenting with a physical sky / atmosphere modeling, and it really seems that the most physically accurate sky is the most beautiful. I think this applies more generally to all light and shadows, and all natural effects which people perceive as beautiful, and at the same time difficult / expensive to recreate on a computer.

> I think this applies more generally

I would say the sky and a private eye's dimly lit, smoke-filled 1920s office are pretty different, actually.

Re: Corners Don't Look Like That: Regarding Screenspace Ambient Occlusion (2012)

#44

Post by jameshart »

Discussed previously here in 2022: https://news.ycombinator.com/item?id=30595038

I still can’t help but read most of this article as a story of a guy trying to prove his theory that corners aren’t actually dark, taking photos and plotting luminance graphs of corners, repeatedly getting these strong vee-shaped graphs that indicate that the surface darkens linearly towards the corner, and just gathering more and more pictures until eventually he finds some which show flat luminance lines, at which point he declares victory because he’s proven that corners don’t darken.

Re: Corners Don't Look Like That: Regarding Screenspace Ambient Occlusion (2012)

#47

Post by ElevenLathe »

Geee wrote: post #30
overgard wrote: post #7

I agree with his overall point, but I would point out: realism is not usually the point, the point is to look good. The problem with realism is once you get past "wow the computer can do that now", it's not very interesting -- most of reality is pretty dull looking!

I don't think this is true at all. I've been experimenting with a physical sky / atmosphere modeling, and it really seems that the most physically accurate sky is the most beautiful. I think this applies more generally to all light and shadows, and all natural effects which people perceive as beautiful, and at the same time difficult / expensive to recreate on a computer.

I personally love the Quake 1 sky textures. It's possible to have a stylized sky in a game that looks good.

Re: Corners Don't Look Like That: Regarding Screenspace Ambient Occlusion (2012)

#48

Post by overgard »

applfanboysbgon wrote: post #11
overgard wrote: post #7

I agree with his overall point, but I would point out: realism is not usually the point, the point is to look good. The problem with realism is once you get past "wow the computer can do that now", it's not very interesting -- most of reality is pretty dull looking!

> most of reality is pretty dull looking! This is extremely untrue. It may be true that you spend most of your time in a dull-looking office or apartment, but most of reality -- at least here on Earth -- is quite visually interesting, and games are usually placed in visually interesting environments rather than set entirely within an office or apartment. Beyond that, I would argue that the entire point of realism is…

I think stylized scenes can be just as immersive. I've never been in a game and been like "GAH this pixel art is throwing me out of it!" I'm not saying realism is without value, just that it's probably a little overrated in the graphics space.

Re: Corners Don't Look Like That: Regarding Screenspace Ambient Occlusion (2012)

#49

Post by dcrazy »

logdahl wrote: post #5

I find this very interesting. I have implemented AO myself and understood that its physically inaccurate (it should really be radiosity presence, not ambient occlusion), but have believed the results to look realistic. Or rather; better than flatly lit, which makes geometry hard to understand. Thank you for these photographs! It would be awesome to have a CG benchmark like this (geometry + light properties) that we c…

Nowadays it’s common for SSAO to actually do local radiosity approximation via ray marching. But back in the day when this article was written, that was too expensive so you approximated it by detecting sharp transitions in the depth buffer.
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