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Won't Fix
Votes
0
Found in
2020.3.47f1
2021.3.21f1
2022.2.13f1
2023.1.0b8
2023.2.0a9
Issue ID
UUM-32753
Regression
Yes
Interpolation between values occurs when the Particle System parameter is set to Curve
How to reproduce:
1. Open the user-attached project “particle-constant-bug”
2. Open the scene “SampleScene”
3. Select GameObject “Particle System”
4. Pause the Simulation and slowly change the field “Playback Time”
5. Observe the size of the particles
Expected result: The particle size changes suddenly as the Curve suggests
Actual result: The particle size changes gradually between the two values; this is not how the Curve looks like meaning the interpolation between the two values occurs
Reproducible with: 2020.3.21f1, 2020.3.47f1, 2021.3.21f1, 2022.2.13f1, 2023.1.0b8, 2023.2.0a9
Not reproducible with: 2020.3.20f1
Reproducible on: Windows 11 Pro
Note: Also reproducible with the other parameters
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Resolution Note:
Hi,
Firstly, thanks for the report - i'm sorry that we aren't going to fix it, because it is a valid bug.
To give more detail - it's very hard to fix, and only affects the Edit Mode playback of systems. You will never see this problem in Play Mode or is a Player.
It's for these reasons that we can't prioritise fixing it at the moment.
It happens because we perform interpolation of all final particle properties when doing the slow-mo scrubbing in Edit Mode, to make everything smooth. We have no way of knowing that one particular size calculation is supposed to be stepped. We can't even know that we have to step the sizes, because, for example, the Size by Speed module might also be applying smooth size changes.
Thanks again for the report though - hopefully knowing that it won't affect a Player/Playmode reassures you that this isn't going to affect the final look of your app, and is only a problem during the authoring process.