Whats the difference between the Ambient Occlusion options?

[ChubbiChibbai]

I'm familiar with SSAO and HBAO somwhat - but what is XeGTAO?
Anyone tested out the options for visuals / performance and can recommend a good pick?

[BirdOfPray]

some discussions say XeGTAO causes crashes

[ChubbiChibbai]

I'm using it with no problems so far so fingers crossed.
Reading up it sounds like the option with the most fidelity but also is the most intensive.

Its used in Ratchet and Clank as well FYI.

[X YdoC]

I am also curious about the AO settings, XeGTAO definitely seems to take a few fps off, but it still runs ok, so if it is the best setting, I suppose I will stick with it. Just with so many different settings, I'm not sure which one is the best.

[ChubbiChibbai]

From what I have read so far it's a much more detailed version of AO. It's still screen space (unlike ray traced AO) but not as expensive as raytraved AO either.

From Sony blog Ratchet and Clank where it was previously used:

“XeGTAO generates a very high-resolution ambient occlusion that shows even the smallest details in geometry,” says Bil. “Overall, the output quality of XeGTAO is very high and results in a pleasant look.”

[Squiggly1]

XeGTAO is more detailed than HBAO+. Here's a video comparing the two. You'll notice a bit more shadow detail in the XedGTAO side of things. So, if you can run it at an acceptable framerate. Do so. It's video card agnostic even though it's Intel tech.

https://www.youtube.com/watch?v=HK1K2V4jczs

[ChubbiChibbai]

Nice find. It really adds some nice subtle extra detail to the more complex bits of geometry. That is in a pretty old game as well which would have had more simple meshes so i can imagine the impact is even greater in more modern stuff.

[JohnTravoltage]

Originally posted by Squiggly1:

XeGTAO is more detailed than HBAO+. Here's a video comparing the two. You'll notice a bit more shadow detail in the XedGTAO side of things. So, if you can run it at an acceptable framerate. Do so. It's video card agnostic even though it's Intel tech.

https://www.youtube.com/watch?v=HK1K2V4jczs

Correct me if im wrong, but the options being displayed in this video are HBAO+ being compared to a general GTAO solution, not XeGTAO.
GTAO just means ground truth ambient occlusion, which is very similar to the idea behind HBAO (Horizon based vs ground based, different names for the same approach).

Anyone can make a GTAO solution and call it that. Call of duty WW2 doesn't have XeGTAO, just a ground truth ambient occlusion solution.

[Slickman]

I compared SSAO quality, HBAO+, and XEGTAO on many scenes. In my opinion SSAO quality is the most consistent across scenes and it's the cheapest on the GPU. HBAO+ is boss when it comes to character faces though.

[ChubbiChibbai]

Originally posted by Slickman:

I compared SSAO quality, HBAO+, and XEGTAO on many scenes. In my opinion SSAO quality is the most consistent across scenes and it's the cheapest on the GPU. HBAO+ is boss when it comes to character faces though.

What do you mean by cosnsistent?

[LilDipper]

HBAO+ is what you want as it is the best, but is very demanding, so if you have a potato for a rig, don't use it, but it will make the game look stupid amazing.

[Gitaroo]

GTAO is the best thing after RTAO I think, XeGTAO is just intel branding version of it and can be implemented into any games and GPU anogstic. nVidia VXAO was suppose to provide more coverage than HBAO+ I think it is not screen space effect so it doesn't have the same screen space limitation but performance cost is very heavy and only used in Rise of the Tom Raider DX11 mode and maybe FF15. GTAO is as good as it gets for screen space AO with reasonable performance cost consider it also in all the CoD games that is suppose to run in HFR.

[ChubbiChibbai]

I wonder why we dont get any ray traced AO options with this title

[Slickman]

Originally posted by ChubbiChibbai:

Originally posted by Slickman:

I compared SSAO quality, HBAO+, and XEGTAO on many scenes. In my opinion SSAO quality is the most consistent across scenes and it's the cheapest on the GPU. HBAO+ is boss when it comes to character faces though.

What do you mean by cosnsistent?

There's certain instances where on the game there will be shelves with vases on them and with HBAO+ the vases will have no shadow, on XeGTAO they will have a faint shadow, and SSAO Quality will have a more pronounced shadow. I don't think either one of the 3 options looks the best for everything and SSAO Quality is the cheapest of the 3. I like HBAO+ for character models and rock surfaces, SSAO Quality and XeGTAO are great for foilage though SSAO Quality will be more pronounced ie the shadows will be darker. I also like SSAO quality best for indoor areas. So in the end I don't think HBAO+ or XeGTAO are worth the performance cost over SSAO Quality.

[ChubbiChibbai]

Thanks for explaining.
Ill try all three. Good to know there isn't one best solution. I guess its just down to preference and performance at this point.

[JohnTravoltage]

Originally posted by Gitaroo:

GTAO is the best thing after RTAO I think, XeGTAO is just intel branding version of it and can be implemented into any games and GPU anogstic. nVidia VXAO was suppose to provide more coverage than HBAO+ I think it is not screen space effect so it doesn't have the same screen space limitation but performance cost is very heavy and only used in Rise of the Tom Raider DX11 mode and maybe FF15. GTAO is as good as it gets for screen space AO with reasonable performance cost consider it also in all the CoD games that is suppose to run in HFR.

Only issue with this is that GTAO is just a general term for an approach to ambient occlusion, actual implementation can vary greatly, especially stylistically. The only thing we know, is that it is a type of ambient occlusion that takes into account the ground plane, similar to HBAO+.

As an example, a game could have an implementation of GTAO which is set up so that it is using barely any samples, is really noisy, and darkens way too much around it. Another game could have a huge amount of samples and could even use a different colour entirely rather than darkening.

Both of these when compared to HBAO+ would have completely different results in comparison.

We can't really use GTAO examples in various other games to compare to XeGTAO since implementation/style is completely different.

In my experience in ghost of tsushima using both heavy/light scenes. All of the AO options seem to run almost exactly the same (even ssao performance) on a 3080. Most notably SSAO heavily darkens areas under grass, and depending on what you like that might be ideal. XeGTAO and HBAO both occlude less, and with a less harsh darkening effect.

XeGTAO seems to darken more areas than HBAO slightly, which can make it less precise in some scenes, and more precise in others depending on the makeup of the scene.

If you want more subtle AO, probably best to stick with HBAO, if you want darker AO, stick with SSAO. If you want a bit of an inbetween, go XeGTAO.