Regression: Particle mirror broken for particular mirrored mesh. #98076

New Issue

Cheerax · 2022-05-12T19:56:26+02:00

Cheerax commented

2022-05-12 19:56:26 +02:00

System Information
Operating system: Windows-10-10.0.19044-SP0 64 Bits
Graphics card: NVIDIA GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 511.65

Blender Version
Broken: version: 3.1.2, branch: master, commit date: 2022-03-31 17:40, hash: cc66d1020c. also version: 3.3.0 hash: 8d9d5da13706
Worked: 3.0.0, commit hash: 8b44b756d850db38ab4d83513682f2012d88a3f4 from branch 3.0.1 to be exact.

Caused by 02ab4ad991

Short description of error
Particle hair x-mirror results in hair going in all directions instead of being properly mirrored, see the following screenshot:

Exact steps for others to reproduce the error

Start from the attached blend file which has an emitter sourced from a base model and mirrored by applying a mirror modifier. I could not reproduce the issue from scratch with simpler geometry and I might have reconnected the hair at some point .
Go into particle edit mode on the Eyebrows_Particle object.
Enable x-mirror in the top-right Options menu.
Observe that the particles change directions.

Here is what it looks like when it's working in the same particle edit mode with x-mirror enabled. The exact commit that introduced the issue is: 77694b571f5bd297ea7228b30f591ebbd333e0ea.

mirror_bug.blend

Exact steps for others to reproduce the error
repro.blend

open file
Particle > Mirror
observe wrong mirroring

**System Information** Operating system: Windows-10-10.0.19044-SP0 64 Bits Graphics card: NVIDIA GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 511.65 **Blender Version** Broken: version: 3.1.2, branch: master, commit date: 2022-03-31 17:40, hash: `cc66d1020c`. also version: 3.3.0 hash: `8d9d5da13706` Worked: 3.0.0, commit hash: `8b44b756d850db38ab4d83513682f2012d88a3f4` from branch 3.0.1 to be exact. Caused by 02ab4ad991 **Short description of error** Particle hair x-mirror results in hair going in all directions instead of being properly mirrored, see the following screenshot: ![broken.png](https://archive.blender.org/developer/F13071203/broken.png) **Exact steps for others to reproduce the error** 1. Start from the attached blend file which has an emitter sourced from a base model and mirrored by applying a mirror modifier. I could not reproduce the issue from scratch with simpler geometry and I might have reconnected the hair at some point . 2. Go into particle edit mode on the `Eyebrows_Particle` object. 3. Enable x-mirror in the top-right `Options` menu. 4. Observe that the particles change directions. Here is what it looks like when it's working in the same particle edit mode with x-mirror enabled. The exact commit that introduced the issue is: `77694b571f5bd297ea7228b30f591ebbd333e0ea`. ![working.png](https://archive.blender.org/developer/F13071194/working.png) [mirror_bug.blend](https://archive.blender.org/developer/F13071208/mirror_bug.blend) **Exact steps for others to reproduce the error** [repro.blend](https://archive.blender.org/developer/F13072630/repro.blend) - open file - `Particle` > `Mirror` - observe wrong mirroring

Cheerax commented

2022-05-12 19:56:26 +02:00

Added subscriber: @cheerax

blender-admin commented

2022-05-12 19:56:26 +02:00

#98030 was marked as duplicate of this issue

Philipp Oeser commented

2022-05-12 21:38:06 +02:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2022-05-12 21:38:06 +02:00

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

Philipp Oeser commented

2022-05-12 21:38:06 +02:00

Can confirm, will check.

Philipp Oeser commented

2022-05-13 15:46:20 +02:00

Added subscribers: @kevindietrich, @JacquesLucke

Philipp Oeser commented

2022-05-13 15:46:20 +02:00

It is indeed caused by 02ab4ad991
It is a relatively recent regression, will set to high prio (could be lowered though since it is about the EOL particle system)

CC @kevindietrich
CC @JacquesLucke

It is indeed caused by 02ab4ad991 It is a relatively recent regression, will set to high prio (could be lowered though since it is about the EOL particle system) CC @kevindietrich CC @JacquesLucke

Philipp Oeser changed title from ~~Particle hair x-mirror broken for particular mirrored mesh.~~ to Regression: Particle hair x-mirror broken for particular mirrored mesh.

2022-05-13 15:46:40 +02:00

Philipp Oeser commented

2022-05-13 15:50:06 +02:00

Added subscribers: @MegaPixol, @OmarEmaraDev, @PratikPB2123

Philipp Oeser changed title from ~~Regression: Particle hair x-mirror broken for particular mirrored mesh.~~ to Regression: Particle mirror broken for particular mirrored mesh.

2022-05-13 15:50:27 +02:00

Hans Goudey commented

2022-05-16 10:33:24 +02:00

Added subscriber: @HooglyBoogly

Hans Goudey commented

2022-05-16 10:33:24 +02:00

@kevindietrich Hey, since the particle system is actively being replaced at this point, feel free to set this as a known issue if you don't plan on fixing it (since importing of curves is being replaced for 3.3 hopefully anyway (D11592)).

@kevindietrich Hey, since the particle system is actively being replaced at this point, feel free to set this as a known issue if you don't plan on fixing it (since importing of curves is being replaced for 3.3 hopefully anyway ([D11592](https://archive.blender.org/developer/D11592))).

Jacques Lucke commented

2022-05-23 10:08:30 +02:00

Hmm, difficult. The change is caused storing correctly normalized coordinates in CD_ORCO instead of unnormalized coordinates (in MOD_deform_mesh_eval_get). Still not sure at which level this can be fixed unfortunately..

Hmm, difficult. The change is caused storing correctly normalized coordinates in `CD_ORCO` instead of unnormalized coordinates (in `MOD_deform_mesh_eval_get`). Still not sure at which level this can be fixed unfortunately..

Jacques Lucke commented

2022-08-24 13:15:28 +02:00

Will change the priority to normal, because it seems unlikely that someone of the core team will work on this soon since the particle system is end-of-live.

carlos puebla commented

2022-09-27 07:11:49 +02:00

Added subscriber: @CarlosPuebla

Philipp Oeser removed the

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Regression: Particle mirror broken for particular mirrored mesh. #98076