mob-sakai/ParticleEffectForUGUI

Is custom simulation space broken?

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#293 opened on Jan 30, 2024

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 (2 comments) (0 reactions) (1 assignee)C# (3,441 stars) (524 forks)batch import
bughelp wanted

Description

I am updating from 3.3.9, and since then the behaviour of custom simulation space seems to have changed. I've got a particle effect inside a scroll rect with simulation space set to custom. When I move the scrollrect, I expect particles to just move with it, preserving their shape, but instead they move up and down way too far. It looks like this is a bug, or maybe custom simulation space is not supported in the current version?

Expected behaviour: particles keep moving up and down in this sin curve like pattern when I scroll

image

Observed behaviour: particles move all over the screen.

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Also, scene preview breaks

image

I have modified the included demo scene to show this behaviour. To reproduce, open the scene and scroll up and down.

CustomSimulationSpaceBehaviourExample.zip

Contributor guide

Tech stack
csharp
Domain
frontend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Unity basicsC#Particle System
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
Investigate the custom simulation space implementation in ParticleEffectForUGUI, focusing on how it interacts with ScrollRect. Review the particle position update logic in the source files, and examine the provided reproduction scene to identify the regression. Check for any changes in Unity's API between versions 3.3.9 and later that might affect custom simulation space behavior.