why some hairs are not moving with dynamic hair? in blender 2.90/2.91 #83730

New Issue

guang liang chen · 2020-12-13T17:45:10+01:00

guang liang chen commented

2020-12-13 17:45:10 +01:00

System Information
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce GTX 670/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 451.67

Blender Version
Broken: version: 2.90.1, branch: master, commit date: 2020-09-23 06:43, hash: 3e85bb34d0
Worked: (newest version of Blender that worked as expected)

Short description of error
why some hairs are not moving with dynamic hair? in blender 2.90/2.91
if I don't modifer the hair weight all the hairs will move,but when I brush some weight to the hair ,
some hairs are not moving in dynamic.

dynamic hair error.blend
Exact steps for others to reproduce the error
[Please describe the exact steps needed to reproduce the issue]
[Based on the default startup or an attached .blend file (as simple as possible)]

**System Information** Operating system: Windows-10-10.0.18362-SP0 64 Bits Graphics card: GeForce GTX 670/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 451.67 **Blender Version** Broken: version: 2.90.1, branch: master, commit date: 2020-09-23 06:43, hash: `3e85bb34d0` Worked: (newest version of Blender that worked as expected) **Short description of error** why some hairs are not moving with dynamic hair? in blender 2.90/2.91 if I don't modifer the hair weight all the hairs will move,but when I brush some weight to the hair , some hairs are not moving in dynamic. ![毛1.gif](https://archive.blender.org/developer/F9506770/毛1.gif) [dynamic hair error.blend](https://archive.blender.org/developer/F9506768/dynamic_hair_error.blend) **Exact steps for others to reproduce the error** [Please describe the exact steps needed to reproduce the issue] [Based on the default startup or an attached .blend file (as simple as possible)]

guang liang chen commented

2020-12-13 17:45:10 +01:00

Added subscriber: @imdjs

Philipp Oeser commented

2020-12-14 10:52:47 +01:00

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

Jacques Lucke commented

2021-01-05 16:43:06 +01:00

Added subscriber: @JacquesLucke

Jacques Lucke commented

2021-01-05 16:43:06 +01:00

Changed status from 'Confirmed' to: 'Needs User Info'

Jacques Lucke commented

2021-01-05 16:43:06 +01:00

I can reproduce the issue in the file. I couldn't reproduce it from scratch in a new file yet. That would be helpful to fix the issue. Can you please provide more precise steps on how to reproduce the issue in a new file?

Philipp Oeser commented

2021-02-11 12:02:08 +01:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2021-02-11 12:02:08 +01:00

@imdjs: did you have the chance to find reproduction steps from scratch? (otherwise we might have to close this)

guang liang chen commented

2021-02-16 08:27:41 +01:00

Added subscriber: @philipp-14

guang liang chen commented

2021-02-16 08:27:41 +01:00

here is another issue file ,but if I reset the number of hair keys and then the issue will gone ,
I find the more large number of hair the easier will be wrong.
error with dynamic hair.blend

@philipp-14 Oeser (lichtwerk)

here is another issue file ,but if I reset the number of hair keys and then the issue will gone , **I find the more large number of hair the easier will be wrong.** [error with dynamic hair.blend](https://archive.blender.org/developer/F9807243/error_with_dynamic_hair.blend) ![hair2.gif](https://archive.blender.org/developer/F9807254/hair2.gif) @philipp-14 Oeser (lichtwerk)

guang liang chen commented

2021-02-16 08:47:26 +01:00

but this file ,no mater how I reset the hair-keys number,The error is still there.
error with a large number of hair.blend
I reset the key number to 15, few hairs are still not moving.only set the number to 7, then the error gone.

it seem that the issue is relate to the number of hair points.the more large number of hair points the easier will be wrong.

@philipp-14 Kant (philipp)

but this file ,no mater how I reset the hair-keys number,The error is still there. [error with a large number of hair.blend](https://archive.blender.org/developer/F9807315/error_with_a_large_number_of_hair.blend) I reset the key number to 15, few hairs are still not moving.only set the number to 7, then the error gone. ![hair3.gif](https://archive.blender.org/developer/F9807377/hair3.gif) it seem that the issue is relate to the number of hair points.the more large number of hair points the easier will be wrong. @philipp-14 Kant (philipp)

Philipp Oeser commented

2021-02-27 19:02:13 +01:00

Changed status from 'Needs User Info' to: 'Needs Triage'

Philipp Oeser commented

2021-09-20 08:19:09 +02:00

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

Philipp Oeser commented

2021-09-20 08:19:09 +02:00

Sorry this has ben lying around for so long, but can confirm.

This is probably the same as #56818 (Hair Dynamics does not work for all strands when hair has been cut)

Sorry this has ben lying around for so long, but can confirm. This is probably the same as #56818 (Hair Dynamics does not work for all strands when hair has been cut)

Dalai Felinto commented

2022-05-09 15:19:22 +02:00

Added subscriber: @dfelinto

Dalai Felinto commented

2022-05-09 15:19:22 +02:00

Thanks for the report. Marking this as known issue since it depends on the old particle settings which is end of life .

Thanks for the report. Marking this as known issue since it depends on the [old particle settings which is end of life ](https://developer.blender.org/tag/nodes_physics/).

Philipp Oeser removed the

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why some hairs are not moving with dynamic hair? in blender 2.90/2.91 #83730