Feature Request Post Processing with multiple cameras is currently very problematic

Thanks for the update! I think people will not at all mind the performance hit nor the alpha blending issues as long as supporting alpha is possible in the first place, as it's a very common use case for cameras, and without it SRP is definitely not at parity with builtin.

 

Still nope?

 

+1

 

+1

 

It's been more than 2 years...

+1

 

It's under planned, happy to see that.

 

+10,000 Please!

 

+1

Example use case I was trying:
2D Parallax with 3 layers
- 1st camera without depth of field
- 2nd camera with some depth of field
- 3rd camera with a strong depth of field

You can see things like this in many games like Darkest Dungeon II, or CloudberryKingdom

 

So we'll have to wait another 2 years for them to do it then if it's only in planned.

 

+1

 

+1

 

+1

 

+1 for UI separate post processing on URP.

 

Is this a related temporary solution?
#14

 

+1 It's okay if the performance is broken, so we need a temporary solution.

 

I was working on a new tool called PULSE - Post-Processing Utilities, LUTs, and Special Effects. It allows you to post process overlay cameras without effecting other cameras. Also you can create your own custom effects with minimal amount of code.

Left is overlay camera with post processing, right is main camera with no post processing:



You can get PULSE on Github: https://github.com/Warwlock/PULSE
You can find installation and usage on Github page.

Also PULSE is part of bigger project called CATS, it is also open source: https://github.com/Warwlock/C.A.T.S

Also there is main thread: https://forum.unity.com/threads/pulse-post-processing-utilities-luts-and-special-effects.1460305/

 

This is blocking my adoption of URP. My current setup (in the built-in pipeline) works like this:

• base camera render a star field
• overlay camera to render the exterior of a space ship (using post-FX profile A)
• overlay camera to render the interior of a space ship (using post-FX profile B)
• overlay camera to render elements I don't want to have post-FX applied to like 3D UI elements
• camera to render the current screen contents to a RenderTexture and blur it (for use in the UI)
• camera to render 2D UI to a texture with MSAA (UI uses SVG and this removes the jagged edges)
• overlay camera to composite the UI into the screen

Seems like this just isn't possible with URP - or it would be a giant pain to get it working.

 

This solution takes some steps but it workd for URP 14.0.8 (Unity 2022.3.6f1) to have transparency working for the environment background solid color with alpha of a "Base" render-type camera having post-processing on, only 1 camera:

1. Create a "Universal Render Pipeline Asset" asset file and a "Universal Renderer Data" (Assets->Create->Rendering->URP Asset (with Universal Renderer) will create both files already referenced). Make sure your custom URP Asset is being used by referencing it at Project Settings -> Scriptable Render Pipeline Settings.

2. Look for the UberPost.shader used for post-processing by your URP version: in your Project tab search for "uberpost" and change the search "In Assets" setting to "All" to see UPM internal packages files as well. Duplicate the UberPost.shader file (that should be at Packages/com.unity.render-pipelines.universal/Shaders/PostProcessing/UberPost.shader) into a folder of your own in /Assets.

3. Open your duplicated version of the original UberPost.shader and look for the fragment shader (it may be called Frag, or FragUberPost or similar, depending on your URP version used) and inside there look for the first real color variable assignation (normally at the

else

of the

_CHROMATIC_ABERRATION

conditional; e.g.

color = SAMPLE_TEXTURE2D_X(_SourceTex, sampler_LinearClamp, uvDistorted).xyz;

) to know the exact texture property name being used (normally it will be either

_SourceTex

or

_BlitTexture

).

4. Go to the bottom of the fragment shader before the last closure and replace

return half4(color, 1.0);

with:

Code (CSharp):

1.  
2. half alpha = SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uvDistorted).w;
3.  
4. return half4(color, alpha);
5.  

That's needed so that manipulating the alpha of the camera environment background color actually makes it transparent (by default it's always 1.0 for whatever reason...).
Here's an example of a custom UberPost.shader file with those modifications.

5. Open the

.meta

file of your custom UberPost.shader in a text editor and copy the

guid

hash

6. Create a "Post Process Data" asset file (Assets->Create->Rendering->URP Post-process Data), open it in a text editor and paste the

guid

hash of your custom UberPost.shader.meta file into the

uberPostPS

property.

7. Select your "Universal Render Data" asset file and replace the Post-processing data file reference with your newly created "Post Process Data File".

8. Finally configure your camera accordingly, make sure the "Renderer" used is your "Universal Render Data" asset file:







Hopefully this will help someone save a lot of time.

 

THANK YOU!
I have been dealing with this problem on and off since 5 months ago!
In the end I settled for having some sort of worse bloom effects because I couldn't properly get post processing while rendering gameobjects in front of unity UI toolkit on a render texture.

And then today I got frustrated and I found this post

You solved my issue and I simply can't thank you enough - so to anyone struggling with this, what pravusjif wrote WORKS.

On a sidenote, I really need to learn to read / write shaders so I could have solved it when I looked into it myself.

THANKS AGAIN!

 

@pravusjif hmm, I have tried, but i'm still not sure. Where my problem is I need to enable post-processing on camera1base, and camera2overlay. But when enable post processing on both camera, the post-processing is multiplied.

Tried to camera2 as base, but it hidden camera1 rendering.

 

Just chiming in with my use-case: I'm looking to do an overlay UI without post-processing in URP 2D, but I don't want to use ScreenSpaceOverlay because I want it to respect my camera's viewport rect. When I do this, the UI camera seems to "undo" all of the post-processing that happens in the main camera. This is especially weird because in the frame debugger I can still see the post processing happening in the main camera's rendering. It looks like it's overlaying the UI camera over the results of the DrawAllRenderers step rather than the final output of the main camera, which is unexpected.

Ideally I could use distinct volumes to only apply some of the post-processing to the UI (essentially what I'm really trying to do is just not have bloom on UI), but I understand how that could quickly get confusing with how alpha is handled.

 

@diesoftgames This might be the same issue outlined here: https://forum.unity.com/threads/pos...amera-stacking-in-unity-2022-3-0-lts.1462307/

For me it was working on 2021LTS and broke when switching to 2022LTS.

 

@restush96 You can just enable post-processing for only the overlay camera and it will be applied to the main camera as well.