Feature Request better SSAO in HDRP

HDRP's SSAO isn't bad, but it really falls short of what you'd expect from HDRP.

This is a visual improvement request, performance is fine.

Let's compare HDRP's SSAO with HBAO:

One of the biggest issues I'm facing with HDRP's SSAO has to do with radius. Most of the time I want to use a larger radius, but HDRP's SSAO makes that hard if not impossible, as you will have issues with small objects and your character's geometry on movement.

Also, with HBAO, things look stable on movement, SSAO artifacts are not obvious at all (still there), compared with HDRP's SSAO where any radius that isn't tiny will have a massive amount of AO popping, and instability on movement.

Maxed AO intensity & radius, no color bleeding or multibounce enabled:

See how smooth the transition with HBAO is compared to HDRP -- although HBAO results in softer, and reduced AO which plays a part but still, you can see the difference.

HDRP's SSAO feels like it doesn't have any information around an object's thickness, all AO ends up being the same. If it could adapt radius, it would be a big improvement.

HBAO also has color bleeding, grounds objects even further, while also taking the environment into consideration. Reducing the usual complaints around AO 'dark corners' -- and offscreen sampling which helps hide AO popping on screen edges.

This isn't to say HBAO is better, in some cases I like SSAO's result more, and vice versa.
Just using it as an example.

Imo SSAO is an integral part of all projects nowadays, I believe SSAO has been the same in HDRP for a long time with no significant changes, which isn't necessarily a cause for change, but seeing the quality I feel like it really shouldn't stop here and should even take priority.

 

You should really try the HBAO asset, it is amazing!

 

Unfortunately, it's not viable for HDRP as it doesn't work with HDRP's fog. AO doesn't consider fog, so it just goes through it, makes it unusable unless you don't plan on using fog.

I'm also hoping HDRP makes so you don't have to kit bash a ton of assets for better visuals, like URP/built in. Always better if it's built in.

 

You could try SSGI, or if you need more accurate SSGI try H-Trace on the asset store.

 

+1 voting for better SSAO on HDRP. Current SSAO also has bigger issues with VR, producing more artifacts and bad aligning between both eyes.

 

+1
i was thinking about this as well.
the transition of HBAO is much smoother than native SSAO.
but the HBAO can't work with hdrp fog.
it's time to have a better native SSAO for HDRP.

 

Imo this is especially important now that we have APV, many props and objects will be lit with APV and thus lack occlusion compared to lightmaps, AO is a must to ground these objects to the world. (It was done with the old probe system as well, but it's possible to light up more objects with good quality compared to the old system)

It's a struggle with the current SSAO, it doesn't have directional AO and the radius issue really limits visuals.
Without SSAO, probe volume lit objects look very flat.

 

It always bothered me how barebones Unity's SSAO in HDRP is. 2 years ago I thought surely they'll improve this over time. I was wrong.

 

+ 1
It's not bad but should be better