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?

[168cm 83kg 13cm]

I've tested all the AO options, and SSAO looks the best, while XeGTAO seems to be the worst. You can see the difference in these two screenshots taken at the very beginning of the game - https://imgsli.com/MjY0OTE5
Notice how there are almost no soft shadows with XeGTAO under character models and the grass thingy on the right looks especially bad in comparison

[X YdoC]

Publicado originalmente por JohnTravoltage:

Publicado originalmente por 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.

Yea, that was basically my conclusion after the small amount of testing I did. SSAO was really heavy, shadows everywhere, HBAO+ was way less, and XEGTAO was in the middle. XeGTAO looked the most realistic from the shot I was testing, but after reading this I learned that it means ground based and HBAO means horizon based, and it could mean nothing, but just common sense wise, this game seems to stem A LOT of it's lighting from strong horizons, so maybe HBAO + is the way to go for realism, based on the way the games lighting SEEMS to be drawn?

[ChubbiChibbai]

Publicado originalmente por X YdoC:

after reading this I learned that it means ground based and HBAO means horizon based, and it could mean nothing, but just common sense wise, this game seems to stem A LOT of it's lighting from strong horizons, so maybe HBAO + is the way to go for realism, based on the way the games lighting SEEMS to be drawn?

That's a really good way to think about it and justify why HBAO+ might be the best option visually.

It also lines up with the Sony article from Ratchet and Clank which says that XeGTAO is comparable to HBAO+ but less intensive. So maybe it was their answer to HBAO+ for the playstation?

[Vault Traveler]

I prefer SSAO because when characters stand in the shadow they seem to float in HBAO+ and XeGTAO, I understand some people dont like the shadow blob under character models but for me its the opposite.

[JohnTravoltage]

Publicado originalmente por X YdoC:

Publicado originalmente por JohnTravoltage:

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.

Yea, that was basically my conclusion after the small amount of testing I did. SSAO was really heavy, shadows everywhere, HBAO+ was way less, and XEGTAO was in the middle. XeGTAO looked the most realistic from the shot I was testing, but after reading this I learned that it means ground based and HBAO means horizon based, and it could mean nothing, but just common sense wise, this game seems to stem A LOT of it's lighting from strong horizons, so maybe HBAO + is the way to go for realism, based on the way the games lighting SEEMS to be drawn?

Fundamentally hbao and GTAO are very similar, in regards to the ground/horizon, its just different names for basically the same principle. However other aspects are different.

In the paper detailing basic GTAO principles, it actually specifices that it is an adaptation of horizon based ambient occlusion, and in that regard, ground/horizon are the same, since its assumed that the ground is a flat plane in both.

[EntenKoeniq]

I made a comparison for you.

I looked at all the details and I think XeGTAO looks the best. The performance is the same for all of them, so it only makes a visual difference.

You're welcome

https://got-oa.key2val.com/

[Roland]

Just stand in a room with a light and cycle between them. The game changes the preview live so you can just pick whatever looks best to you.

I forgot which one I went with now but it's usually HBAO+ and I felt it looked pretty inaccurate here.

Like I was standing in a room with a flame as the only light and looking at a set of shelves and some of the options weren't shadowed enough and some were darker or larger than they should have been for the shadow cast.

I did not compare performance because my choice did not lower my frame rate from 60, so performance impacts didn't matter

Edit:
After looking at this:

Publicado originalmente por EntenKoeniq:

I made a comparison for you.

You're welcome :temhug:

https://got-oa.key2val.com/

I realized I picked SSAO Performance, because I remember thinking it's odd that to me it looks better than Quality