URP Post-Processing: Ambient Occlusion availability?

Hello, its great that URP is now equipped with its own set of post/processing effects. However the AmbientOcclusion effect is still currently missing and is not even mentioned in in-progress documentation on Github.

Can we get any info about the Ambient Occlusion effect status - it means will it make it into 2019.3?

Thanks

 

Ambient Occlusion isn't available because URP doesn't render a geometry normals texture, which is the pillar of any ambient occlusion effect:



I don't know if they're adding the option (can't see anything related on GitHub). But URP is apparently also getting Deferred rendering in the future, where normals are always available, making AO work out of the box. So I suppose they're either going to implemented it at some point, or wait until Deferred rendering is in place.

 

An idea: calculate an approximate normal from the depth texture (that is available) and use that? If you are comfortable with creating your own post-process effect that is.

Useful article on the subject (especially "Cetral differences for Terrains"): http://www.iquilezles.org/www/articles/normalsSDF/normalsSDF.htm

 

I've successfully been using this hack: https://github.com/beinteractive/LWRPAmbientOcclusion with PostProcessing v2 in LWRP but haven't yet tried with URP.

 

yes, it supports MultiScaleVO

which relies on the depth buffer only as far as i remember.

it was not really stable (image wise) but under certain conditions better than nothing.
doing an extra normal pass or using multiple rendering targets when rendering forward lighting sounds a bit bandwidth heavy to me, so i guess we have to live with a rather simple ssao solution.

 

@larsbertram1 The hack I posted above simply re-enabled Unity's own PPv2 AO under LWRP. But as 2019.3 has ditched PPv2 I suppose it won't work anymore. Are there currently any working URP 2019.3+ solutions that you know of? Any of your assets?

 

i don't know.
i just wanted to clearify that normals are not mandatory if you use some special SSAO techniques.
they are super good to have but maybe just too expensive – at least in case of URP and forward.

 

I am generating a custom normals texture in my URP project. I guess you could use that for AO.
https://alexanderameye.github.io/edgedetection.html

 

Unity really needs to sort out this custom post processing asap. URP seems like incomplete and feels like it has gone backward now.

 

I can't believe what a mess it is!, I mean SSAO is a trivial old school method and there is no proper implementation with URP. So, what is the best way to get normals? if URP is so flexible how come you can't even do SIMPLE SSAO???

 

I like the tutorial but are there just no source files?

 

Source files linked through pastebin.

 

In the works. https://github.com/Unity-Technologies/ScriptableRenderPipeline/compare/universal/ssao
Anyone care to try?

 

Looks like its been almost a month since they worked on this. Real bummer that we dont have AO with this "new and improved" Unity. Feels like I downgraded my product.

 

Maybe it's been a month because it's ready and just waiting for another branch to be merged into master first. Could be close. You never know. Deferred lighting in URP is apparently ready to be merged, according to a recent commit.

 

I tried it. It worked in the editor initially but after building for iOS the effect no longer worked both in the build and in the editor.

 

If I may, I don't think SSAO is a good fit for URP. If we get deferred, it'll maybe be fine since a big chunk of the performance cost will be paid regardless, but other than that, it's generally an effect that makes things look actively worse and is most definitely not worth the huge performance cost.

Especially with low settings, the only thing it does is make corners look like the have mold. IMO if your game needs SSAO to look good, you are probably doing something wrong. With all that said, I would be interested to find out why people keep asking so much for it.

 

I very much like the look of AO, so I disagree with you.

 

This is pretty much the primary reason for switching from URP to HDRP. All shadergraphs still work once master node is swapped out, I am able to get same graphics as before but with actual ability to perform this effect and many others. I also find that in general, HDRP is actually easier for me to use than URP which seems to have far more issues version to version. I also no longer feel like I have downgraded my graphics by using SRP, which I definately felt with URP

HOWEVER using the custom normals texture by @alexanderameye works for URP! So you can build a AO on top of that.

@alexanderameye please make more tutorials, your edge detection tutorial was great but really waiting for that follow up tutorial that does it as an image effect! Please keep them up you could easily become a major player on the tutorial scene if you fill your site with a little more content!

 

Yeah maybe I'll do that, but just feels really weird doing a low-poly game in HDRP... I feel like they did the change to SRPs like a year too early.

 

Not at all, your just getting a larger set of features. Can make any game you want in it, low poly included. However you can always try generating custom normal texture and then writing an AO effect on top of that, that will work just fine too and above a user has linked to a tutorial on the normal texture part.

 

I wrote a basic ScriptableRenderFeature based on the SSAO implementation from the SRP github. Just add it to your RendererData and plug in the shader and noise texture and it should work. It's not a great implementation: it has to blit twice because blitting can't have the same source and destination.



ScriptableRenderFeatures are a really neat way of extending the pipeline for things like this, but the documentation isn't great and you kind of have to do a lot of digging through the code to understand how to use them.

Happy to answer questions

 

@Soul_Without Looks cool!

Just add it to your RendererData and plug in the shader and noise texture and it should work

How do I go about adding it to my RenderData, completely new to me.

@GameDevCouple_I Why did you choose HDRP over the old "default"? Was more leaning towards just going back to that, since I assumed HDRP would add a lot of bloat I dont need to the project.

 

When you first created your Universal Render Pipeline Asset (the one you select in project settings) it should have created another asset for the renderer. In the inspector window for that asset click the plus in the Renderer Features section and you should see the new feature

 

View attachment 517100

@Soul_Without
Edit: I downloaded 2019.3 but unfortunately it does not pick up your script, see attachment.

 

According to the public roadmap AO is only still being considered. Confusing.

 

And reflection probe box projection in a year or so, which is kind of bizarre, since it's roughly ten lines of shader code and it runs even on 5 year old mobile phones, so I don't know why they need a year.

 

Code are pretty basic, looks like more proof of concept instead a real production ready code.

 

There are some solutions out there that don't use the normals buffer.
The first Crysis SSAO was only based on depth textures and a very low sampling ratio.
I remember a Toy Story 3 SSAO (http://advances.realtimerendering.c... 2010 Advanced RealTime Rendering Course).pdf) managed to get also low count sampling for SSAO
There's also Neural Network AO that uses a block of depth pixels for a lookup texture for the AO result.

If URP is also aiming for mobile, I would rather have also these options instead of only a high quality-ish one that requires compute shaders, normals, depth, etc.

Also the issue with rolling 'our own' AO solutions is that Unity's Post procesing (PPv2 or URP-builtin) does A LOT of stuff at their final Uber shader, where they start mixing and combining previously prepared results (bloom results, dof results, motion blur results, etc).
It would be nice if we could write to those 'target textures' to be later used in the final Uber shader that way we could roll our own solutions too (provided a set of rules of how those resulting textures need to be set for compatibility with the Uber shader).

 

Wow! Thanks a lot for this contribution.
Would it be possible to add a 'downsample' option, to make it run on a lower res target?

Had a question, if you happen to be acquainted with these RenderPassFeatures, have you found a way to be able to feed a render target result from one blit to the next? Suppose I add a downsampling pass and leave that result on a temporary render target (that's not released), to then use it on a next blit pass feature to, say, gaussian blur it... so on and so forth.

 

Thank you for sharing this!!!

 

The wait is over! HBAO is now URP friendly. Working beautifully. What a difference a good AO can make.

 

Edit nvm im stupid.

 

For the record, @jimmikaelkael has said that HBAO will see performance gains once Unity adds view normals. But working fine for me.

 

is it possible to enable post-processing via script?

 

You can enable/disable the PP volume, for example. But you should ask in a different thread because this one is more specifically about ambient occlusion in URP.

 

Is there a free alternative? :\

 

intergrated lightmapper can do AO baked into Lightmap

 

For some reason it doesn't bake for me in URP, are there any steps to do it?

 

if you for example use a directional light and set it to Bake and the strength (brightnes) is very low it still bakes you AO into Static objects.

 

no news about AO post processing in URP?

 

There is if you check the github. It will be out quite soon.

 

Link?

 

Part 1 is here: https://github.com/Unity-Technologies/Graphics/pull/24

Part 2 is over here: https://github.com/Unity-Technologies/Graphics/pull/8

It seems like a series of bug fixes have been prioritised for merge before to these pull requests, but I hope @ElliomanGames gets to them soon!

 

i just used the super affordable HBAO from assets store it's amazing it's fast i love it!!!
using URP 7.2.1

 

It will be faster still when it can tap into depth normals, the dev told me.

 

Isn't it say AO is available? https://docs.unity3d.com/Packages/c...l/universalrp-builtin-feature-comparison.html

 

No. If you look again you’ll notice it says “in research”.

 

Oh ok, I see. I was looking at the global illumination part.