The URP post processing “Bloom” has too much draw calls.

The post processing stack v2 bloom has a paramter that can control the blur times of the effect.
But after i upgrade to URP.The bloom does not contains that paramater.
So the drawcall of Bloom is increasing from 2 to 22.
It's performance awful.
I can't use it anymore.

 

PostProcessPass.cs

const int k_MaxPyramidSize = 16;


this controls the downsampling times.

this should not be a const value.

Because of the purpose the URP,it should be performance friendly to mobile or vr platforms.

 

A 16-texture bloom is absolutely insane, that's movie-CG level bloom, overkill for just about any existing use case tbh. As you mentioned, there's no reason that should be a constant - but looking at the naming scheme, it looks like Unity intend for it to be like that :/

 

If I recall correctly you have worked with post processing a bunch so I trust your experience , do you have any manual tips to squeeze better performance out of URPs post processing?

Seeing stuff like this is very concerning, as I imagined Unity would atleast have options for the fastest possible settings.

Cheers

 

Given the lack of real customization options they give you in-editor, you have one choice if you stick with URPs post-processing: Edit it and maintain your own version. Decreasing the bloom k_maxBloomPyramid (IIRC) var from 16 to 8 will instantly save you 8 passes for instance, the rest of what you save is up to you.

 

That's all true, including what your developer said - but they obviously haven't thought about all the use cases for bloom in a universal render pipeline.

Mobile bloom, more often than not, just requires a small glow around objects - even modern mobile games like TES:Blades don't use more than that, which can be achieved in ~2 textures, maybe 4 for very high quality bloom. Even if the extra individual passes in the GPU profiler don't look like they add up to much, any mobile dev will tell you that looping through two for loops ~12 more times than they need to, while adding 12 extra passes, is far from best practice. It is trivial to at least add in the option for mobile users to set the maximum # of passes and maximum bloom texture size - something that as you mentioned is also an issue, and should be controllable in the pipeline (as it is in some 3rd party assets, like PRISM).

 

Interesting, can we use use some sort of SRP batcher, that we no need to bother of draw calls number for post process effects?

 

I agree - stop running the URP demos on giant PC monitors and run them on 5" mobile and Nintendo Switch screens - which is what we are all using URP for. The default should be maximum performance for all settings first and foremost. Much easier to ramp up the visuals on our end (the game developer side) than to examine every minute setting to squeeze out performance.

 

Physical screen size != Render resolution

There are 5" devices from 2013 with current average PC monitors "1920x1080" resolution, the switch does 1080 tv to 720 hand held.

Question... is all of this poor performance due to depth texture being forced on by the render pipeline???

 

Yes, it is far too costly for mobile platform currently

 

Yes please options to choose half or more or full

 

Wasn't "performance by default" supposed to be a thing that Unity is trying to achieve? What if we don't need "very wide blooms" on the screen, but much more subtle glows? We pay for it regardless. Please expose the quality options instead of shipping your tech demo code and calling it production ready.

 

I think it will ultimately come down to the choices. Just enable the iteration numbers etc exposed as public value so the developers can choose the value they like.

 

I was waiting for the "optimized" URP PPv3 just to see this, interesting. Can you just expose as much parameters as you can instead of telling us that already heavy PP effect should have more draw calls for a sake of nothing. I already have 20 FPS with only bloom being enabled (and 2 static sprites on the scene) with current LWRP PPv2.

It's obvious you'll never be able to develop a performant mobile game using URP + PPv3. Look at any developer conference out there and see how people achieve performant bloom on mobile devices. There are so many hacks, they fighting for every ms and you just waste precious resources on unnecessary stuff. Look at the Raid Shadow Legends speak from your OWN conference for example.

It's an another proof that if you won't start developing your own production ready games you will never provide anything good for us.

 

Well whenever this kind of thing happens in Unity we had plan b called asset store... but the problem with current case is that the asset store developers cant make alternative solution (yet) for the post processing in urp. Which, is ironically, in my opinion the worse situation to worry about... Personally I never used ppsv1 or ppsv2 in non srp applications because of either lesser performance or lesser quality of it. Sometimes it makes me wonder if this is actually a business model? Dont get me wrong. I still like Unity for its flexibility and as a tool.

 

I disagree. They renamed it to Universal Render Pipeline from LightWeight because it was meant to target a wide range of devices. If they keep removing features soon we'll be left with monochromatic 16 shades of grey rendering and a max display of 640x480.

It's a universal solution (allegedly... I don't know how universal it is, the results are below expectations so I'd expect it should be able to run on a potato), not mobile only. Plus Android is not a phone only OS, you can have Android on a TV device.

 

The most universal solution is to expose as many performance-related parameters as possible. Not to keep such basic performance sensitive parameter under the hood. I have no problems seeing 16-texture bloom on URP as default as long as I can control that option without creating my own PP effect.

 

I do tend to agree. Personally I think it's maybe not the best time to be using Unity... the old render pipeline is not getting any more love - there's been issues with flickering shadows since like 2010 and they still persist to this day, except the current stance is "move to URP or HDRP instead, we're not fixing that" except when you go to URP the shadows are pretty much even worse... I don't know. Maybe one day they'll get it right

 

Nope. Grand strategy games and RTS games need optimization for everything. Please dont make assumptions like this.

But I agree. URP is because we want fastest, not prettiest. So default should be fastest.

 

Haha dam, came here wondering why i was wasting milliseconds on bloom and how to fix it, cool to see its intended and there's no fix

 

Worth mentioning that they added more control over the bloom (maxIterationCount and downsampling), but it's in a different branch which is not merged and release yet.
more info in here: https://forum.unity.com/threads/post-processing-and-urp-the-plan.795456/page-3#post-5558251

 

Hey

How/where did you change the amount of downsamples in PPv2? I haven't seen that parameter, but I would like to further optimize the bloom in PPv2.

 

when will be come shader quality switch feature on URP 10 ??

 

when k_MaxPyramidSize = 2 you can have some bloom in Oculus quest. But 4 or 8 ---- nope.
I didn't work on empty project. But I have a need to edit this file please do not reset the code every single time.

 

I read the bloom shader and script and real time it does indeed, more than 4 iterations later and the resolution is negligible!
But there are a couple of fast bloom tools on the asset store, which only use 1/8th resolution for calculations and no dithering, but lose the Gaussian blur.

All in all, bloom can be chosen between cpu and gpu.

 

i already profile it on my target device, i exposed the property and reduce it to 4, it gave us huge MS benefits.
(it wont look as good)


pd; we decided to make or own bloom (more control for blurry type and texture size)

 

Unity really needs to expose more paramaters. Set the default you want, but let us have the ability to change it easily.

 

I completely agree. I don't care what the default setting the Unity thinks it is supposed to be good. We should have complete control over the parameters and expose them so we have choice on what we think it is good for each project cases.

 

In Unity 2021.3.8f1 (as of now), How can I change k_MaxPyramidSize?
I'd be very helpful.

 

My dude... Implying that a 10% performance gain its a small thing is sooooo wrong for a variety of reasons... You should not treat developers like that, being a developer yourself (i assume you are), I mean, its just insane to read such comment. Anyway, using 2021.3.12f1 here and i can tell you, URP is the worst it has ever been right now. How come we are in the year 2022 and we have worse technology available for us devs than in 2018? Yes i know, its an exageration, but be sure as hell that it does feel like that some times, specially when you see things like this one, a 2022 bloom PPFX is absolute garbage when you compare it with the bloom PPFX we had back in the day (around 2015-2017)... And how come that nowadays everything feels so damn bugged and strict? i remember all a while ago pretty much all effects had a ton of config option and you could even edit the code/shaders without much trouble... Ngl, unity's way of doing thing in the last couple of years has been just dissapointing, tbh it seems like the fact of naming the engine versions as the YEARS is a complete S*** show of a race nobody is able to win, cause my dude, we are at the doors of 2023 and the most reliable stable versions to work with are between 2018-2020... Thats just dissapointing, but hell, what could we expect from an administration which bussiness model revolves around hiding its own brand from players, right?

 

Couldn't agree more!

 

I enabled bloom and went from 30 (target) to 22 FPS. Couldn't find any meaningful parameter to tune the performance, then found this thread. It's really disappointing this is still the case in 2024.

This old documentation has 2 sets of bloom (optimized and normal) with many settings well documented for each effect. It looks like the mobile optimized variant was dropped entirely at some point.

10% can be 24% and more depending on specs, load and so on. I don't know why this optimized version couldn't be included in PPV2 or URP post processing stack. Current implementation is overkill for my needs and I need the extra performance.

 

Funny how that post was before the whole unity debacle of this year hahah
BUT ITS STILL HAPPENING in 2022.3.18f1 hahahaha

 

Universal RP v 14.0.8 (or possibly earlier) has added in some options for us. Bloom now has Downscale (quarter, half) and Max Iterations (2-8) properties for us to tweak. Max iterations can bring down draw calls as you would expect.

Thanks for listening, devs!

 

+1 Thank you!