Particles do not react to collision objects anymore #89583

New Issue

Christian Holl · 2021-07-01T17:28:29+02:00

Christian Holl commented

2021-07-01 17:28:29 +02:00

System Information
Operating system: Windows 10 Pro - Version 2004 (Build 19041.1052)
Graphics card: NVidia RTX2070Super (8GB)

Blender Version
Broken: 3.0.0-alpha+master.5a64c687ddcc
Worked: at least in 2.92

Particles do not react to collision objects anymore.

In default start-up file:

Add collsion physics to the default cube.
Add a new cube above the default cube.
Create a new particle system to the new cube
Let it play (space bar)

in 3.0 Alpha it shows no collision to the default cube below:

at least in 2.92 everything works as expected:

**System Information** Operating system: Windows 10 Pro - Version 2004 (Build 19041.1052) Graphics card: NVidia RTX2070Super (8GB) **Blender Version** Broken: 3.0.0-alpha+master.5a64c687ddcc Worked: at least in 2.92 Particles do not react to collision objects anymore. In default start-up file: 1. Add collsion physics to the default cube. 2. Add a new cube above the default cube. 3. Create a new particle system to the new cube 4. Let it play (space bar) in 3.0 Alpha it shows no collision to the default cube below: ![image.png](https://archive.blender.org/developer/F10207982/image.png) at least in 2.92 everything works as expected: ![image.png](https://archive.blender.org/developer/F10207986/image.png)

Christian Holl commented

2021-07-01 17:28:29 +02:00

Added subscriber: @MoonMoon

hal9000 commented

2021-07-01 22:50:02 +02:00

Added subscriber: @hal9000

hal9000 commented

2021-07-01 22:50:02 +02:00

Hi there,

I am currently trying to reproduce your setup with a fresh build, but unfortunately without success. Would it be possible for you to upload the .blend file shown in the images - or a recreated one with the same issue?

Some times a simulations is cached during replay and not updated appropriately after changing the settings of any related object. Even restarting the replay/going to frame 1 does not trigger the cache to be cleared. To eliminate this it can help to move the emitter a bit to trigger a 'fresh' animation. (This happened once to me during my recreation attempt when I played around with the order of the steps you presented.)

Does the issue persist even after saving and restarting Blender?

Best regards!

My Setup:

System Information:
Operating system: Windows 10 Home (10.0.19042)

Blender Version:
Working: 3.0.0-alpha+master.17a67bf778b8

Hi there, I am currently trying to reproduce your setup with a fresh build, but unfortunately without success. Would it be possible for you to upload the .blend file shown in the images - or a recreated one with the same issue? Some times a simulations is cached during replay and not updated appropriately after changing the settings of any related object. Even restarting the replay/going to frame 1 does not trigger the cache to be cleared. To eliminate this it can help to move the emitter a bit to trigger a 'fresh' animation. (This happened once to me during my recreation attempt when I played around with the order of the steps you presented.) Does the issue persist even after saving and restarting Blender? Best regards! **My Setup:** System Information: Operating system: Windows 10 Home (10.0.19042) Blender Version: Working: 3.0.0-alpha+master.17a67bf778b8

Christian Holl commented

2021-07-01 23:24:24 +02:00

particle_collision.blend
Hi @hal9000 ,
Please find attached the .blend-file which I created in the exact steps I described in my report.

"Some times a simulations[...]"

I tried your advice but the particles are still falling straight through the default cube.

"Does the issue persist even after saving and restarting Blender?"

Yes, I can still reproduce this issue with 5a64c687dd which seems to be the current alpha version promoted on
https://builder.blender.org/download/daily/
even if I close and restart Blender.

An older build of 3.0a, just a few days ago (e1a719c043) seems also to be fine! If I open the attached file with this build it works as expected.
So I guess somethings wrong with this particular build: 5a64c687dd

If there this behavoir does not appear in newer builds I think you can close this report.

Thank you very much!

Kind regards

[particle_collision.blend](https://archive.blender.org/developer/F10208248/particle_collision.blend) Hi @hal9000 , Please find attached the .blend-file which I created in the exact steps I described in my report. "Some times a simulations[...]" - > I tried your advice but the particles are still falling straight through the default cube. "Does the issue persist even after saving and restarting Blender?" - > Yes, I can still reproduce this issue with 5a64c687ddcc which seems to be the current alpha version promoted on https://builder.blender.org/download/daily/ even if I close and restart Blender. An older build of 3.0a, just a few days ago (e1a719c0433b) seems also to be fine! If I open the attached file with this build it works as expected. So I guess somethings wrong with this particular build: 5a64c687ddcc If there this behavoir does not appear in newer builds I think you can close this report. Thank you very much! Kind regards

hal9000 commented

2021-07-01 23:44:13 +02:00

Hi @MoonMoon ,

thank you for uploading the file! All collisions were simulated correctly on my setup for the afore mentioned build and also for v2.93.0.

So I guess somethings wrong with this particular build: 5a64c687dd

I agree with you. My build is about one day older than yours.

If there this behavoir does not appear in newer builds I think you can close this report.

It would be great if you could do that. Please be aware that I am just a normal user and cannot close this thread.

Thank you for spotting the issue!

Best regards!

Hi @MoonMoon , thank you for uploading the file! All collisions were simulated correctly on my setup for the afore mentioned build and also for v2.93.0. > So I guess somethings wrong with this particular build: 5a64c687ddcc I agree with you. My build is about one day older than yours. > If there this behavoir does not appear in newer builds I think you can close this report. It would be great if you could do that. Please be aware that I am just a normal user and cannot close this thread. Thank you for spotting the issue! Best regards!

hal9000 commented

2021-07-02 01:22:03 +02:00

Update: Found the time to do the check. The issue was fixed in the mean time.

Summary:
The folowing commits happened in this order:
e1a719c043 (worked)
17a67bf778 (worked)
5a64c687dd (broken)
0ff1c38fcc (worked again)

The broken version did not work on my setup as well.

Update: Found the time to do the check. **The issue was fixed in the mean time.** Summary: The folowing commits happened in this order: e1a719c0433b (worked) 17a67bf778b8 (worked) 5a64c687ddcc (broken) 0ff1c38fcc8c (worked again) The broken version did not work on my setup as well.

Evan Wilson commented

2021-07-02 02:35:08 +02:00

Added subscriber: @EAW

Evan Wilson commented

2021-07-02 02:35:08 +02:00

Changed status from 'Needs Triage' to: 'Resolved'

Evan Wilson closed this issue

2021-07-02 02:35:08 +02:00

Evan Wilson self-assigned this 2021-07-02 02:35:08 +02:00

Evan Wilson commented

2021-07-02 02:35:08 +02:00

Thank you for the report @MoonMoon, and @hal9000 for the investigation.

This was broken by {4f3ec011016c} and {5a64c687ddcc} and fixed by {8c3855dc6e9}.

The fix will be in the next daily build. In the meantime, you can use the previous daily build.

I'll close this thread.

Thank you for the report @MoonMoon, and @hal9000 for the investigation. This was broken by {4f3ec011016c} and {5a64c687ddcc} and fixed by {8c3855dc6e9}. The fix will be in the next daily build. In the meantime, you can use the previous daily build. I'll close this thread.

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Particles do not react to collision objects anymore #89583