Activision Ambient Occlusion GTAO

[anonymous_user_cb9ec8a0]

Hi all,

someone know if and when this AO from activision will be supported on Unreal?

[Activision Research | Home

https://www.activision.com/cdn/research/PracticalRealtimeStrategiesTRfinal.pdf](Activision Research | Home)

[darthviper107]

They probably don’t have any plans to currently

[anonymous_user_cb9ec8a0]

@darthviper107

They probably don’t have any plans to currently

thx for the reply !

well it’s really really pity

i hope nvidia will get some know how from this amazing tecnique

[anonymous_user_c94f194d]

@darthviper107

They probably don’t have any plans to currently

Based on what?

This is already in engine. Released on 4.17.

Unreal Engine 4.17 Released!

This feature just needs better integration with different ambient occlusion sources. SSAO or DFAO does not currently use this technique. It’s really cheap and easy to implement. Actually I am going to implement it now myself.

[anonymous_user_c94f194d]

I implemented colored multibounce AO for SSAO static lighting pass. Pull request is here. https://github.com/EpicGames/UnrealEngine/pull/4334

[anonymous_user_cb9ec8a0]

@anonymous_user_c94f194d

I implemented colored multibounce AO for SSAO static lighting pass. Pull request is here. https://github.com/EpicGames/UnrealEngine/pull/4334

thx sooo much man
you are the best!

[Daedalus51]

@anonymous_user_c94f194d

I implemented colored multibounce AO for SSAO static lighting pass. Pull request is here. https://github.com/EpicGames/UnrealEngine/pull/4334

So does that mean that I have to bake bent normal maps for every asset that I want the colored AO to work for? Cause thats how it is suggested in the release notes. If thats the case its almost useless for environments since you cant afford that load of extra texture samples for all those special normal maps. The hard part is to make stuff look better inside the budget. Of course I can make stuff look better by just adding things on top that make it more expensive

Dont mean to be offensive here, but I am just stressing this from a production point of view!

Also, I do believe that the benefit of GTAO is that you dont need additional input maps, so “we already have that” doesnt really count as an argument to me

[Chosker]

@anonymous_user_c94f194d

Based on what?

This is already in engine. Released on 4.17.
https://www.unrealengine.com/en-US/b…-4-17-released

This feature just needs better integration with different ambient occlusion sources. SSAO or DFAO does not currently use this technique. It’s really cheap and easy to implement. Actually I am going to implement it now myself.

you mean that this GTAO technique is really the Bent Normals thing?
also does that mean you’d need a bent normal for every asset in the game? :eek:
[edit] Daedalus beat me to it, but he expresses my own concerns very well

[anonymous_user_fbe2d247]

@Daedalus51

So does that mean that I have to bake bent normal maps for every asset that I want the colored AO to work for? Cause thats how it is suggested in the release notes. If thats the case its almost useless for environments since you cant afford that load of extra texture samples for all those special normal maps. The hard part is to make stuff look better inside the budget. Of course I can make stuff look better by just adding things on top that make it more expensive

Dont mean to be offensive here, but I am just stressing this from a production point of view!

Also, I do believe that the benefit of GTAO is that you dont need additional input maps, so “we already have that” doesnt really count as an argument to me

you mean that this GTAO technique is really the Bent Normals thing?
also does that mean you’d need a bent normal for every asset in the game? :eek:
[edit] Daedalus beat me to it, but he expresses my own concerns very well

Where did I mentioned bent normals? GTAO is just formula how to turn SSAO + albedo as close to ground truth as possible. This is implemented in engine with function named AOMultiBounce. Currently this is applied only to materialAO. I implemented this for ssao static fraction in this PR. https://github.com/EpicGames/UnrealEngine/pull/4334

Patch notes said this quite clearly.

Finally we’ve added a multi-bounce approximation for occlusion. Instead of AO or reflection occlusion shadowing the first bounce we use an approximation of what many bounces will result in. Bright materials get less dark and colored materials get more saturated.

Edit: Actually GTAO is also the “cosine” part but this should already be included to materialAO. For SSAO this part still could be improved.

[Chosker]

you didn’t mention Bent Normals, you just linked to the release notes which mostly talks about Bent Normals
you’re right that it mentions multi-bounce approximation afterwards, but it’s all contained within the Bent Normals feature explanation of the notes so it really feels like it’s part of the Bent Normals. it goes like this:

New: Bent Normal Maps and Reflection Occlusion
Bent normals are this and that
With this information we can do multiple things to improve indirect lighting. Bent normals are used with AO to improve …]
We also use this information in a powerful but less traditional way, for reflection occlusion. …]
Finally we’ve added a multi-bounce approximation for occlusion…]

is this AOMultibounce really decoupled from Bent Normals?

[anonymous_user_fbe2d247]

you didn’t mention Bent Normals, you just linked to the release notes which mostly talks about Bent Normals
you’re right that it mentions multi-bounce approximation afterwards, but it’s all contained within the Bent Normals feature explanation of the notes so it really feels like it’s part of the Bent Normals. it goes like this:

is this AOMultibounce really decoupled from Bent Normals?

Yes. You can look at BasePassPixelShader.usf.

[ldcue]

@anonymous_user_fbe2d247

Yes. You can look at BasePassPixelShader.usf.

Does it means Bent Normals won’t be needed anymore?

[Chosker]

Yes. You can look at BasePassPixelShader.usf.

Currently this is applied only to materialAO.

that explains why I haven’t seen any of it, as I don’t really use Material AO
you PR sounds quite interesting. I hope they integrate it and improve upon it (but we know how PRs go these days)

[anonymous_user_fbe2d247]

@Ley0k

Does it means Bent Normals won’t be needed anymore?

Bent normals are meant for directional occlusion. It’s better than just uniform occlusion.

[anonymous_user_fbe2d247]

that explains why I haven’t seen any of it, as I don’t really use Material AO
you PR sounds quite interesting. I hope they integrate it and improve upon it (but we know how PRs go these days)

It’s really simple to integrate PR that just alter shader files. You don’t even need source code build.

[John_Alcatraz]

GTAO has now been added to UE4: https://github.com/EpicGames/UnrealEngine/commit/065e4d71a84c73e5ee59081d85bc3c99e8554911

[MaximeDupart]

D a m n (<- why is this a censored word?!), maybe i’ll start investigating in upgrading to 4.25. SSAO is killing my project on smaller budget rigs.