Why you're getting a mystery TempBuffer on mobile device after removing Post Processing from project

https://issuetracker.unity3d.com/is...r-does-not-disable-cameras-m-forceintort-flag

Took me a couple days to track down this issue, happening in 2018.3.1f1. Cross posting it here so anyone else googling for "what is creating TempBuffer unity mobile ios" might stumble across it and not beat their head against a wall for days.

Basically if you ever used Unity's Post Processing stack in your project, then removed it when you realized it is death on mobile devices, it doesn't clean itself up all the way on any camera that had a Post Process layer attached to it. The fingerprints are if you run the profiler and open the rendering frame debug window, you'll see an unnecessary execution of "Camera.ImageEffects" calling a Hidden/BlitCopy shader and copying this buffer to your final window target.

The quick workaround is to turn debug mode on Inspector on your camera object, then turn off the "Force Into RT" checkbox. Instant performance and memory win!

Unity's PP stack should really come with a giant red flag warning to NOT use it on mobile targeted projects.

 

Thanks, I got hit by this.

 

Thank you so much for posting this!

 

Thanks ! I just came into this problem.

 

I'm having the same problem.

How did you find out about this and what does "Force into RT" really means?

 

You just saved me after a 2 month long search for answers. I had a strange jitter in oculus quest. I just couldn't find why! It was that Force into RT thing! You are Awesome!

 

Got hit by this as well, but the camera already has Force Into RT off.

 

Cheers! Unity PP Stack is really a hell for Mobile.

 

After many builds and tests on android I realized that this 'force into rt' was killing my game performance on mobile... Them I searched for it on google and found out this thread! Thanks to share this man!

 

I am seeing similar on my project. I have checked that the "Force into RT" is off.

In the frame debugger, I am seeing two clear's of mystery 1x1 tempbuffer's for both my main camera and a secondary camera.



I have no idea what these are, or what system owns them. I don't know how I can find out more information about them in Unity. I want them gone

(Unity 2021.2.7f1)

 

I'm facing the same problem but I'm sure I turned off "Force into RT".

 

Well, I finally found out what the problem was:
the AdditionalLightsShadowCasterPass and MainLightsShadowCasterPass will always call ShadowUtils.GetTemporaryShadowTexture(...) to create a 1x1 TempBuffer When there are no shadow-casting main（additional）lights in the scene or "Cast Shadows" is off in URP assets.

 

I am facing the same problem too...
It seems there's no other way than waiting for the official fix.....