Texture sheet animation module Sprite mode not working

[soimy]

Describe the bug
Texture sheet animation module Sprite mode not working, hole texture of a multi-packed sprite is shown.

To Reproduce
Steps to reproduce the behavior:

1. Set particle system sheet animation module on, mode to sprite
2. Assign several sprites from a multi-packed spritesheet.
3. UI particle set animatable properties to _MainTex_ST
4. Playback, whole spritesheet shown instead of sprite.

Environment (please complete the following information):

• Version [3.0.0-preview.11]
• Platform: [e.g. Editor(Windows)]
• Unity version: [e.g. 2020.1.0b8]

Additional context
Digging through the code, I found that UIParticle.cs will set textureSheet.uvChannelMask

ParticleEffectForUGUI/Scripts/UIParticle.cs

Line 93 in b0e2688

textureSheet.uvChannelMask = (UVChannelFlags) (sprite && sprite.packed ? -1 : 0);

comment out this line works for me.

[mob-sakai]

@soimy
Sorry for my late reply.
I would like to know more about this issue.
Could you please attach a minimal project that reproduces the issue?

[soimy]

I will.
Can you tell me why textureSheet.uvchannelMask is set to -1 when using multi packed sprite?
It works when uvChannelMask is untouched(UV0)

[mob-sakai]

@soimy
Sorry for my late reply.
The issue is reproduced in my environment.

Can you tell me why textureSheet.uvchannelMask is set to -1 when using multi packed sprite?

To support the Sprite Atlas.

[soimy]

uvChannelMask is usually handled by the user via the dropdown menu. Multi-packed sprite sheet won't work when uvChannelMask is set to Nothing(-1)

[mob-sakai]

Yes, you are right.
I should not have used it as a workaround of any kind.

The problem to begin with was that I couldn't get the actual texture from the sprite.
The sprites in the Sprite Atlas do not return a packed texture in editor mode.

I just found a non-public API that gets the packed textures from sprites.
I'll test it later.

[mob-sakai]

I did it! 👍
This API solves the issue!

Before:

After:

[github-actions]

🎉 This issue has been resolved in version 3.0.0-preview.16 🎉

The release is available on:

• GitHub release
• v3.0.0-preview.16

Your semantic-release bot 📦🚀

[soimy]

Thank you!