World simulation bug due to transform movement

[wanwanyahoo]

how to make particle already emitted not follow emit transform?
I try simulation space to world but is wont't work after add ui particle script

[mob-sakai]

Hi @wanwanyahoo
Thank you for reporting. :)

I would like to know more information on this issue.
Can you submit a small reproducible project for this issue?

[ALPSquid]

Hi @mob-sakai
I've identified the same issue with world space particles and it's very simple to reproduce. The issue being that already emitted particles don't stay in their world position when the particle system transform is moved.

Steps

1. Create a normal particle system (no UI Particle component) and set the simulation space to world.
2. Move the particle system transform.
   • Notice how already emitted particles stay in the current position regardless of where the transform is moved. This is the expected behaviour.
3. Add a UI Particle component.
4. Move the particle system transform.
   • Notice how already emitted particles move relative to where the transform is moved. This is not the expected behaviour.

Commit 68da045 seems to have broken this behaviour as removing the added positioning code (Ln 305 - 325) makes world space particles behave as expected.

[mob-sakai]

@ALPSquid @wanwanyahoo
Thanks.
Please tell me more informations about this issue.

• Unity version
• ParticleEffectForUGUI version
• Platforms (Editor[Windows/Mac]/Standalone[Windows/Mac]/iOS/Android)
• etc...

[wanwanyahoo]

Thank you for reply so quickly. Unity version:2018.3.13 particleeffectforugui version: 2.2.0 platform:windows 10 unity editor 发自我的 iPhone

…

在 2019年5月1日，下午7:32，Takashi Sakai ***@***.***> 写道： @ALPSquid @wanwanyahoo Thanks. Please tell me more informations about this issue. Unity version ParticleEffectForUGUI version Platforms (Editor[Windows/Mac]/Standalone[Windows/Mac]/iOS/Android) etc... — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or mute the thread.

[ALPSquid]

Unity version: 2018.3.8f1
ParticleEffectForUGUI version: 2.2.1
Platform: Editor - Windows 10

[mob-sakai]

Unity version: 2018.3.10f1
ParticleEffectForUGUI version: 2.2.1
Platform: Editor - Mac

Edit: This issue is reproduced when scaling mode is set to Local.

Hmm...
In my environment, it seems to work well.

test.unitypackage.zip

@wanwanyahoo @ALPSquid
Can you submit a small reproducible project for this issue?

[mob-sakai]

Oh, this issue is reproduced in my environment when scaling mode is set to Local.
It works well when scaling mode is set to Hierarchy.

[wanwanyahoo]

simulation mode need set to world 发自我的 iPhone

…

在 2019年5月2日，下午12:24，Takashi Sakai ***@***.***> 写道： Oh, this issue is reproduced in my environment when scaling mode is set to Local. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or mute the thread.

[mob-sakai]

@wanwanyahoo @ALPSquid
What's RenderMode do you use?

• Screen Space - Overlay
• Screen Space - Camera
• World Space - Camera

[ALPSquid]

@mob-sakai I'm using Screen Space - Camera

[wanwanyahoo]

screen space-camera 发自我的 iPhone

…

在 2019年5月7日，下午8:04，Takashi Sakai ***@***.***> 写道： @wanwanyahoo @ALPSquid What's RenderMode do you use? Screen Space - Overlay Screen Space - Camera World Space - Camera — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or mute the thread.

[mob-sakai]

I have a good news!
I found a more accurate calculation model and it will solve this issue!

Before

After

[mob-sakai]

@wanwanyahoo @ALPSquid
Import this package and test it.
If there is no problem, it will be released as v2.3.0. :)
v2.3.0-pre.unitypackage.zip

[wanwanyahoo]

Thank you very much.I will give feedbacks after testing. 发自我的 iPhone

…

在 2019年5月7日，下午11:11，Takashi Sakai ***@***.***> 写道： @wanwanyahoo @ALPSquid Import this package and test it. If there is no problem, it will be released as v2.3.0. :) v2.3.0-pre.unitypackage.zip — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or mute the thread.

[ALPSquid]

@wanwanyahoo @ALPSquid
Import this package and test it.
If there is no problem, it will be released as v2.3.0. :)
v2.3.0-pre.unitypackage.zip

@mob-sakai
That seems to be working great, cheers! I'm not able to test any other use cases at the moment, just the Local Scale, World Sim in Camera Screen Space, but that's working as expected.