Huge memory leaks TempBuffer.RenderTexture using softmask

[novavision]

Describe the bug Using SoftMasks in multiple screens in the game cause 150mb memory leak creating up to 50 render textures.

To Reproduce Steps to reproduce the behavior: Create multiple scroll views with 1-2 softmask images in each scrollable item.

Expected behavior SoftMask not spam the RenderTextures for each UI image with this component attached

Screenshots

Environment (please complete the following information):

• Version [1.0.0-preview.14]
• Platform: [Editor(Mac), iOS, Android]
• Unity version: [e.g. 2020.1.17]
• Build options: [IL2CPP, .Net 4.x]

Additional context Add any other context about the problem here.

[mob-sakai]

@novavision Thank you for your reporting!

[evgeny-detkov]

Hey! We also have this problem. Please resolve the issue as soon as possible. Thank!

[mob-sakai]

@evgeny-detkov @novavision Could you please attach a minimal project (included Assets, Packages and ProjectSettings directories) that reproduces the issue?

[evgeny-detkov]

@mob-sakai LINK to test project

[mob-sakai]

@evgeny-detkov Thanks!

[mob-sakai]

@evgeny-detkov Create a parent SoftMask to share a single RenderTexture. Set up as follows:

1. Select Canvas/Scroll View/Viewport game object and convert Mask component to SoftMask component from the context menu (Convert to SoftMask).
2. Fix 2 warnings.
3. Select Canvas/Scroll View/Viewport/Content/GameObject ~ GameObject(97) game objects and disable Ignore Parent and Part Of Parent.
4. That's all. :tada:

Fixed test project

soft_mask_testject.zip

[novavision]

Thanks for explanation, I tried adapt your test scene to my hierarchy and it seems working fine. But I got question regarding to my case (I think it's pretty common UI structure):

I got 20+ screens, some of them has ScrollRect (~10) with SoftMask used in their children. Some screens has >1 ScrollRect. In terms of memory optimization, using your solution above, it's better to attach the SoftMask to the parent (screen object). Even in this case I will have ~10 RenderTexture in buffer. What if I add 'SoftMaskit to most parent object? Like mainCanvas`? Will it negatively affect to the performance?

[mob-sakai]

Could you please attach a minimal project (included Assets, Packages and ProjectSettings directories) that reproduces the issue?

[novavision]

It's not an issue, it's a question, related to buffered RenderTexture optimization.

[mob-sakai]

If the SoftMask buffers are the same size (= Down Sampling Rate), they will be recycled.