Graphics.Blit Tiled GPU perf. warning: RenderTexture color surface was not cleared/discarded

What am I doing wrong here?

I have a script that runs on the Update loop. I have 2 RenderTexture assets. I just want to blit into them with a material. Yet I get Tiled GPU Perf warnings.

I don't want to discard the contents, I want to keep the contents

Code (CSharp):

1. private void Update() {
2.  
3.         if (renderTexture && heightTexture && material && heightMaterial) {
4.  
5.             //heightTexture.DiscardContents();
6.             //renderTexture.DiscardContents();
7.  
8.             Graphics.Blit(null, heightTexture, heightMaterial, 0);          
9.             Graphics.Blit(heightTexture, renderTexture, heightMaterial, 1);
10.  
11.             material.SetTexture(Uniforms.HeightTex, renderTexture);
12.         }
13.     }

Even if I call DiscardContents, I still get these warnings. Why? I can't even use Temporary ones either, still warns.

How are you supposed to use Graphics.Blit into a texture without these perf warnings?

 

Use MarkRestoreExpected. I wrote a little more on the warning here.

 

Thanks

 

You do it as follows: Just change setting of Unity: Edit -> Graphic Emulation -> No Emulation