SSAO samples vs quality

[serotonin]

SSAO is a graphic technology that's still pretty ambiguous to me. I've never had a game before that gave me the option of adjusting its number of samples, or its resolution quality, so when considering these options in Amnesia, I'm at something of a loss. I don't really have a sense of how these values truly impact what I'm seeing in the game.

With my system, it turns out that I can either set it to 16 samples and High quality, or 64 samples and Medium quality, and still maintain good framerate.


My question to you all is this:

What's more desirable, in terms of the visual impact -- 64 samples over 16 samples, OR High resolution quality over Medium resolution quality?

I note that the default "High" basic quality setting in the game's launcher config sets the SSAO to 16 samples and Medium resolution. Is anything greater than 16 samples truly noticeable? On the same note, is High SSAO resolution really all that much better looking than Medium SSAO resolution?

Because Amnesia is such a low-light game with somewhat subtle graphical effects, and especially because a restart is necessary when changing SSAO values, it's been hard for me to really distinguish the in-game visual differences between these settings.

[Cyborg34572]

Hmm id like to know this aswell. You should try screenshots, Take a screenshot of a wall using medium -32 samples, then take a screenshot of the same wall/lighting with high -16 samples, then compare the screenshots.

[caseystryker]

I honestly can't tell the difference between having it off and having it set at 16.

[Tayrtahn]

From the Troubleshooting Guide:

- SSAO Quality. Having this to anything but medium is at own risk. High takes 4 times the time to rendered and should not be on unless you have a monster of a computer.

- SSAO Samples: Keep this at 16 if you want to keep your sanity. Anything else is very demanding. Feel free to try though Smile

Just from reading that, I'd guess that while there's a difference between SSAO on and SSAO off, increasing the quality and samples only provides a tiny improvement.

Which makes sense... if I understand the idea of SSAO correctly, increasing the quality just makes it a bit more accurate. It's a bit like how shadow quality works - better settings will clean up the edge of the shadow a little at what can be a significantly increased processing cost, but even low quality shadows are a major visual boost over no shadows.

[Thomas]

Quick descriptions:

Quality:
This is the size of the ssao buffer, which at medium is 1/4 of screen size (eg 400x300 on a 800x600 resolution) and at high it is the same size. This makes high ssao less blurry and block but 4 times slower!

Samples:
Ssao is performed by check testing the depth around each pixel on the screen. 1 Sample = 1 test. The more samples the less noise. Note that since the samples are often pretty near the pixel, at certain resolutions there is NO difference between 32 and high samples sizes, because after 32 samples, there is no more pixels left to test!

Hope that clears some stuff out!

[Cyborg34572]

Quick descriptions:

Quality:
This is the size of the ssao buffer, which at medium is 1/4 of screen size (eg 400x300 on a 800x600 resolution) and at high it is the same size. This makes high ssao less blurry and block but 4 times slower!

Samples:
Ssao is performed by check testing the depth around each pixel on the screen. 1 Sample = 1 test. The more samples the less noise. Note that since the samples are often pretty near the pixel, at certain resolutions there is NO difference between 32 and high samples sizes, because the after 32 samples, there is no more pixels left to test!

Hope that clears some stuff out!

Lower samples has more noise?, hmm i might lower my ssao samples then, i love noise effects .