Feature Request Occlusion probes or a similar feature - Forest/trees comparison inside

This is a perfect fit or HDRP and quite literally makes all the difference.
Left as you can guess is without, bottom right is with. The difference says it all, fidelity shoots up x50. The above image is using Unity HDRP.

This is also done on CryEngine and makes vegetation look unbelievably good.
Cryengine uses SVOGI though, not just occlusion probes. so it has nice and fast realtime GI (I believe 2 bounces in kingdom come)
Kingdom come deliverance using cryEngine 3 (we're at 5 now):
(has the BEST terrain and vegetation I have seen, check it out)
\


Amazing, isn't it. Forests look stark without it. It really makes all the difference.
Most major games nowadays are open world, with vegetation and a big world.

I specifically work with big terrains and outdoor scenes and seeing my forests/trees looking like the top left image hurts . I know it was suppose to come to the engine some time ago, but it never happened, which was quite disappointing.

Also, it's not just terrains. Sometimes you can't bake lights in your game, and maybe you don't want to -- but still want your interiors to be lit correctly, with a nice sky light falloff.
You wouldn't have to bake lights to get nice interiors without sky light everywhere.

This is a request & discussion thread if anyone would like to chime in, but I will keep hoping

 

Totally agreed.
this feature is important if Unity want to have some place in AAA game titles.
or nobody will choose Unity when they are working on a good looking game with large forest.

 

I definitelly agree... I was thinking it is already implemented, isnt it?

 

On the API level yes.

And Raytraced Occlusion probes is making some level of appearance.

Someone is creating the DFAO variety of this on the forums somewhere.

And paired with SSGI though heavy. Might be useful for 33.33ms target projects.

Obviously raytraced GI and AO as well, but these usually won't work well at scale for large high density scenes at all.

It is very much a tough spot for large external scenes and you are left to consider relying on realtime or screenspaced solutions that still lacks in the visual department against it's baked counterpart.

 

It really is. Makes the next-gen and old-old gen difference when it comes to vegetation.

Occlusion probes, and motion vectors for instanced meshes are the two things we really, really need for amazing open world graphics.

Currently motion vector doesn't support instanced objects, so if you place grass using the terrain detail mesh, or trees, or place them manually through instanced or indirect instanced API, there won't be motion vectors on them. You obviously need instancing for grass or have your FPS drop to 5.
TAA is important for a nice clean smooth image.

 

Isn't probe volume the same thing as occlusion probes? Except it's better because it can capture not only sky occlusion information but GI bounces as well. They already working in HDRP quite some time but isn't finished yet so we can expect improvements in workflows and quality.

 

I don't think so, although I'm not sure. to be honest I haven't tried it yet, should check it out sometime soon.

 

https://github.com/Unity-Technologies/Graphics/commit/d0b072126fad8cbc87f8539dc12c239310abe095
Here is the wip draft of the docs

 

And pretty screenshot from HDRP 12 What's new page

 

from my recent testing APV doesn't really support it.
It's currently just a light probe replacement. Although it's actively under development so who knows what it'll be in the future. They can be something really nice in the coming updates, if the developer keeps working on the feature. I have high hopes

Really want occlusion probes, really makes the vegetation/forest (open world) look so good.

 

Dunno, i just tested and it works pretty decent to me. Second screenshot - only probe volume, no lightmaps or ambient occlusion

 

@Onigiri
Can you please show us how you achieved this? Which hdrp version you used? Or some screenshots?

 

I'm using 2021.2 and HDRP 12.1. Check this doc on how to enable probe volume https://github.com/Unity-Technologies/Graphics/commit/d0b072126fad8cbc87f8539dc12c239310abe095
Here's my settings, almost all defaults


And dont forget to switch GI receiving to lightprobes in your meshes

 

without APV:


with APV:
Probes are visible in the APV image, but as you can see it's identical with the exception of darker ground shadows. I don't see any occlusion.
Activated probes everywhere as mentioned in the doc, trees are static and contribute to GI, set to light probes.


And this picture is with no ambient sky light:


As far as I know, APV is similar to LPV, but better workflow.

 

I don't think APV is meant for this, but it's also better to have probes that just capture occlusion, nothing extra like GI and so on. I don't want any of that in my huge terrain with a ton of vegetation, I just want occlusion.

 

Maybe it is because you added those threes like terrain detail?

 

they're meshes, there is no terrain

 

They are all black? If so i don't think they are working correctly here

 

I tried tests as well every time I get assertion errors, however, it still worked in some scenes with primitives others not

 

https://www.twitch.tv/videos/1194884167?t=02h21m41s
so much valuable information in that stream. I wish they showed code, but oh well

In this timestamp vod link it shows Outer wilds developers implemented an "occlusion" volume feature, they have 0 baked lights but have occlusion -- so they can have interiors and all that stuff, without needing to bake light to get rid of the ambient light. I honestly would love this, even If i ignore vegetation, I can do things without light baking.
Some projects (like outer wilds) can't have baked lights. Some don't want to bake lights, etc.

But if you have an interior that connected with the world outside, you have to bake, otherwise ambient light will ruin the interiors. And you can't change ambient light to 0 since the user can just look at the outside world while inside.

 

Didn't they say that those are negative lights? In BIRP with deferred you can do this by making a new light buffer and set it as multiply blends instead of additive to remove light, or apply it into Ambient Occlussion buffer.
Well those was in BiRP though, not sure about HDRP. . .

 

I want light occlusion in URP, not HDRP. Everyone is mostly using URP for higher performance on regular hardware, and I don't see any reason these probes couldn't be SRP-neutral instead of HDRP-only.

 

A work around for now is to use reflection probes with multiplier set to zero(or close to zero) but than u don't have reflections on your reflective surface(can be fixed if another reflection probe can be used for the reflective objects... Maybe can be achieved with layers) and cannot use SSGI

 

Of course, would be great to have it on URP as well.


Ideally it would be a feature for all SRP.
HDRP is the AAA focused render-pipeline, so it's more expected for it to provide such a feature (maybe one day )
where URP has been quite slow with any features outside of parity. Part of that is due to the high number of platforms holding them back, and it seems they won't add anything if it doesn't run everywhere.

 

hmm, I tried it in interiors to get rid of ambient light but it didn't work

 

Than try enabling ssgi.... Or try using black custom reflection texture

 

or you can try using a proxy mesh with decal shader that only affect occlusion output

 

not as a nice work flow as adding probes however we made a tool for baking AO by baking into vertex color alpha channel into any mesh and then have the AO setting in shader.. takes a bit longer than perhaps slapping some probes in scene but each model can be set from material just as you need it

 

Nice, bit confused though.
This effects the sky ambient lighting?
so interiors would have no sky lighting inside, deep vegetation would occlude sky light to varying degrees, etc.
or is it just AO?

 

The problem of probe volume is that it is just some kind of "voxel based lightmap".
so once you done it,you can never change the lighting for it.






The biggest advantage of splitting "Occlusion Probes" and "Light Probes" is that you could use "Occlusion Probes" as some kind of "Voxel Based Occlusion Maps" and you do not need baking the ambient lighting color in it.

So you could use it in a fully dynamic lighting scene.

Actually there should be a system that only bake "Occlusion Maps" for your scene and use lightmap uvs for these baked "Occlusion Maps".

so we could have dynamic lighting while having better occlusion maps.

the performance and the lighting details should be much much better than realtime GI from Enlighten.

I know you will lose the baked ambient color ( but you will have the PBS ambient light which is not bad at all) and some light bounces, but when you are working on outdoor environment those things won't be such important any more. performance and detailed soooooo soft shadow from "Occlusion maps" are more important.

 

and the solution i talked above should get some similar results like the DFAO in this post

and the performance could be way better.

Graphics - [WIP] SDF^3 - Real Time Ray Tracing Distance Fields - DFAO and Soft Shadows for Unity3D - Unity Forum

 

Oh i've been waiting for this asset, is it released already?

 

nope,more like it's dead...

 

welp. . . RIP then. . . .

anyway using APV for canopy occlussion might not the best way currently but it's kinda work i guess. . .

no APV

With APV

 

Imagine sending PLM to do this job? It'd fall back to CPU faster than a ZX spectrum would melt. I think for the forest case anyway, it would make sense to do this problem in 2 passes:

1. the self-AO of the leaf/branch shading, this can be baked as a coarse bent normal or just AO in verts
2. the ground shading... this could be done by approximating the leafy area with huge spheres, which can easily then be tested for distance against the ground = fast planar lightmap which you can blend into the real lightmap on the ground.

Such an approach would at least be computationally fast.

 

Per Vertex AO would mean all tree are unique mesh or all tree have the same AO then. . .

 

Not at all. The AO for vegetation is baked into vert channels so I don't see why you would think that is unique (for just the leafy area, for itself - it's not supposed to be leaf vs leaf on separate objects to begin with).

You will find you can use any strategy for a local AO like sphere distance for the entire vegetation area of the tree. This is not something that would break batching if done right with a large number of remedial strategies available, depending how little or how much of that you'd need.

I've read a few papers that approximate this with spheres, it's worth looking into. I don't have any links to hand, but even cryengine does use sphere approximations too if memory serves.

 

AO basically is the increasing or decreasing for high or low indirect lighting
you could bake the range from super dark to a more realistic soft as you need and this is controlled per material inside or out .. in my case in the shaders i have a toggle to switch the source from baked or texture .. each solution has its place for best use .. combine with a post effect for global its very powerful

 

Halo infinite..
I still have hope

 

+1 vote for this... URP also needs this

 

Come on,Unity !

people need this.

 

I'm trying something similar. I modified(hacked )) URP to get ambient light from reflection probe. It works ok but there's a catch. Can't rotate reflection probe volume.

 

Been testing out a nice forest demo, and in the same time checking out HDRP's SSGI in 2021.2.
Using SSGI you can get somewhat similar results to occlusion probes, in it that sky light is shadowed and so forests/trees look much nicer.

Although SSGI is, as the name implies, screen-space, so that in itself is a big limitation.
Still, this gives you a glimpse at how forests would look with occlusion probes (or something similar).


I'm also using SSAO, which helps a lot, but struggles with distance AO.


Trees with no SSAO, and no SSGI:


Tree with SSAO enabled (High intensity), but no SSGI:


Tree with SSGI, but no SSAO:


And tree with both enabled:

 

Forest with both disabled:


With SSAO only:


with SSGI only:


I suggest opening pictures in different browser tabs and jumping between them to easily compare the difference.
SSGI is actually pretty good in outdoor areas.


The issue is the performance cost.
If you disable full resolution, it actually becomes pretty damn fast. Can get around 2.6 milliseconds on a GTX 1070.
But if that's disabled, there's a good amount of noise on the grass and in general. I assume it uses half res or quarter res, i'm not sure.

 

SSGI in hdrp really sucks, the ghost effect is just too heavy.
and the performance sucks too.

i don't know why can't they just add the color bleeding effect in ambient occlusion to give us some similar results and much better performance.

horizon based ambient occlusion done it so well.

 

Sad thing is HBAO doesn't work correctly in HDRP, it renders over HDRP's volumetric fog. Cause HDRP doesn't have the right injection point for that not to happen.

https://forum.unity.com/threads/mis...pipeline-cant-do-custom-ssao-in-hdrp.1173797/

 

Though the highly experimental Probe volumes do work well in most cases and is far better performant than SSGI ( cause baked) it's may not be as great for the outdoors, which I honestly thought it was going the become essentially the occlusion probes.

I do hope this in general makes some great headway though.

 

Back when the demo was released, the developer for it planned on releasing it.
It was so "basic" to implement but life changing for vegetation

Reminds me of this:

(I realize the dev is not "lying" here, life happens, just a funny reference -- and todd is impossible to dislike)

 

I guess this is some progress: https://portal.productboard.com/8uf...ion?utm_medium=social&utm_source=portal_share

 

Oh boy. It's under consideration but it's progress

Vote for it if you can guys.
Seems like it might work for real-time as well. This will be a big graphical push, especially to vegetation/forests. Although this is will be good in general, not just for vegetation.
Hopefully we'll hear more about it soon (2022.2 please.. )