Question UI elements appearing in output RenderTexture of Graphics.Blit.

Hi everyone,

I’m working on a terrain generation system which will utilize shaders . I want to be able to combinate layers of different noise types so I created a scriptable object that stores some noise settings. The scriptable object also has a RenderTexture that shows a preview of the noise generated with the given settings. The RenderTexture gets refreshed in OnValidate (the code is quite simple), sometimes I can see parts of the Unity Editor UI (see attached image) in the generated RenderTexture. It’s quite annoying does anyone have any idea what causes this?

Code (CSharp):

1.  
2.         private void GeneratePreview()
3.         {
4.             Material mat = NoiseMapUtils.SetupNoiseMaterial(noiseMapData);
5.             NoisePreview = new RenderTexture((int)previewSize, (int)previewSize, 1);
6.             RenderTexture tmp = new RenderTexture(NoisePreview);
7.             Graphics.Blit(tmp,NoisePreview,mat );
8.         }
9.         private void OnValidate()
10.         {
11.             SyncSettings();
12.             GeneratePreview();
13.         }

 

Very strange. Maybe you can find out with a RenderDoc capture.

Actually, looking at your code, it's no surprise. You are copying an uninitialized render texture with random contents to NoisePreview.

 

Thank you, your input helped me fix the issue. I didn't know that RenderTextures are created with random context, haven't used them in this way before and didn't even think about that. Everything is working correctly now (also addressed the memory leaks which I was causing by not releasing the previously created RenderTextures).

 

Hi, im having the same issue ^^, how did you fix this?

 

Hi,


Turns out the problem was still there, I didn't test long enough. Even after I made sure all render textures are created and had a black texture copied to them the same thing kept happening.


In the end I fixed it by applying a slight delay between OnValidate and the function that creates the preview. I think this is a bug.

Code (CSharp):

1.         private void OnValidate()
2.         {
3.             NoiseSource.noiseSettings = noiseSettings;
4.             GeneratePreview();
5.         }
6.  
7.         async void GeneratePreview()
8.         {
9.             #arbitrary delay
10.             await Task.Delay(5);
11.             if (noisePreview != null)
12.             {
13.                 noisePreview.DiscardContents();
14.                 RenderTexture.ReleaseTemporary(noisePreview);
15.             }
16.  
17.             noisePreview = NoiseSource?.Generate((int) textureSize,noiseStrength,textureOffset,textureTiling);
18.         }