Rigify Meta-Human Neck Bone stretching #74483

New Issue

Andy · 2020-03-06T03:55:12+01:00

Andy commented

2020-03-06 03:55:12 +01:00

System Information
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce GTX 1080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 442.19

Blender Version
Broken: version: 2.82 (sub 7), branch: master, commit date: 2020-02-12 16:20, hash: blender/blender@77d23b0bd7

Short description of error
This may not necessarily be an error, but it results in Odd if not completely wrong behavior.

Create a new file.
Add armature Human Metarig
Generate Rigyfy Rig.
Enter Pose Mode
Grab neck bone, and G Z Upwards, or around.

You'll see arms, breast, clavicles, just assuming weird shapes.
https://gyazo.com/f0b77fbd8d42d36da57828e98f281aa4

I do not have an older version to test at the moment, but I'm fairly sure that in prior version moving the neck caused stretching of the neck - not all the other bones that go with it. This is an issue specifically for the Breast bones, since they scale badly.

**System Information** Operating system: Windows-10-10.0.18362-SP0 64 Bits Graphics card: GeForce GTX 1080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 442.19 **Blender Version** Broken: version: 2.82 (sub 7), branch: master, commit date: 2020-02-12 16:20, hash: `blender/blender@77d23b0bd7` **Short description of error** This may not necessarily be an error, but it results in Odd if not completely wrong behavior. 1) Create a new file. 2) Add armature Human Metarig 3) Generate Rigyfy Rig. 4) Enter Pose Mode 5) Grab neck bone, and G Z Upwards, or around. You'll see arms, breast, clavicles, just assuming weird shapes. https://gyazo.com/f0b77fbd8d42d36da57828e98f281aa4 I do not have an older version to test at the moment, but I'm fairly sure that in prior version moving the neck caused stretching of the neck - not all the other bones that go with it. This is an issue specifically for the Breast bones, since they scale badly.

Andy commented

2020-03-06 03:55:12 +01:00

Added subscriber: @MostHostLA

Ivan Cappiello commented

2020-04-02 14:59:50 +02:00

Added subscriber: @icappiello

Ivan Cappiello commented

2020-04-02 14:59:50 +02:00

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

Ivan Cappiello commented

2020-04-02 14:59:50 +02:00

issue confirmed. It is probably related to the new rig types.
there are some difference in how the constraints are done in this spine setup vs the old one.
to make it work again as it was before this are the required changes:

• remove constraints from ORG-spine.003

change the DEF-spine.003 constraints as follows:

• Copy Transforms (target Bone: tweak_spine.003)
• Damped Track (target Bone: tweak_spine.004)
• Stretch To (target Bone: tweak_spine.004)

EDIT:
this is not working if only spine.003 is fixed.
all the constraints on spine bones have to be moved from ORG to its DEF correspondent.
all the spine ORG-bones have to be unconnected-childs of their correspondent tweak.

issue confirmed. It is probably related to the new rig types. there are some difference in how the constraints are done in this spine setup vs the old one. to make it work again as it was before this are the required changes: • remove constraints from ORG-spine.003 change the DEF-spine.003 constraints as follows: • Copy Transforms (target Bone: tweak_spine.003) • Damped Track (target Bone: tweak_spine.004) • Stretch To (target Bone: tweak_spine.004) EDIT: this is not working if only spine.003 is fixed. all the constraints on spine bones have to be moved from ORG to its DEF correspondent. all the spine ORG-bones have to be unconnected-childs of their correspondent tweak.

Alexander Gavrilov was assigned by Ivan Cappiello

2020-04-02 15:00:46 +02:00

Ivan Cappiello commented

2020-04-02 15:11:22 +02:00

@MostHostLA if you don't need all the new FK options in the new spine, you can use a temporary fix reverting to old spine system.
In order to do so you have to:

• select neck_bone in edit mode and enable the connected option in the bone properties panel. Then go in pose mode and remove the rigify property (spines.super_head)
•select the first spine bone in pose mode and change the rigify property from "spines.basic_spine to" "spines.super_spine"
•generate the rig

@MostHostLA if you don't need all the new FK options in the new spine, you can use a temporary fix reverting to old spine system. In order to do so you have to: • select neck_bone in edit mode and enable the connected option in the bone properties panel. Then go in pose mode and remove the rigify property (*spines.super_head*) •select the first spine bone in pose mode and change the rigify property from "spines.basic_spine to" **"spines.super_spine"** •generate the rig

Demeter Dzadik commented

2020-05-20 15:14:55 +02:00

Added subscriber: @Mets

Demeter Dzadik commented

2020-05-20 15:14:55 +02:00

I gave this thing a shot, but I definitely want to hear what Alexander thinks about the solution in that patch. I also proposed two alternatives, including considering this as an unsupported feature, which would be a big shame, but certainly the easiest solution. ;)

Ivan Cappiello commented

2020-05-20 15:42:51 +02:00

@Mets i'd like to have some more information about this from @angavrilov. I believe he changed the hierarchy for a reason, still this leads to an unintended behaviour (stretching and skewing).
Looking from a different angle, i believe that if the skewing/scaling issue is fixed, the general way the spine works now is pretty nice.
This has been around for a while. And is actually classified as a bug since skewing shouldn't happen. So if @angavrilov has no other clever solution right now i'd be prone to accept the patch.

@Mets i'd like to have some more information about this from @angavrilov. I believe he changed the hierarchy for a reason, still this leads to an unintended behaviour (stretching and skewing). Looking from a different angle, i believe that if the skewing/scaling issue is fixed, the general way the spine works now is pretty nice. This has been around for a while. And is actually classified as a bug since skewing shouldn't happen. So if @angavrilov has no other clever solution right now i'd be prone to accept the patch.

Alexander Gavrilov commented

2020-06-02 12:54:03 +02:00

Added subscriber: @LucianoMunoz

Alexander Gavrilov commented

2020-06-02 12:54:03 +02:00

Could somebody provide a real practical example of these controls (neck and spine tweaks) being used in this way, with an actual character mesh (could use some generic free body), and how the same action worked better in 2.79? It's difficult to understand the animator's intended use for this control and the best solution with just a bare rig.

Demeter Dzadik commented

2020-06-03 11:56:03 +02:00

I quickly slapped the human metarig onto Rain to illustrate the issue with a mesh:

rigify_bug-2020-06-03_11.54.58.mp4

I quickly slapped the human metarig onto Rain to illustrate the issue with a mesh: [rigify_bug-2020-06-03_11.54.58.mp4](https://archive.blender.org/developer/F8573878/rigify_bug-2020-06-03_11.54.58.mp4)

Ivan Cappiello commented

2020-06-09 16:00:58 +02:00

@angavrilov the issue has been reported almost 3 months ago. If there aren't any other objections and you have no other solution on the table, i am going to accept the patch proposed here by @Mets.

@angavrilov the issue has been reported almost 3 months ago. If there aren't any other objections and you have no other solution on the table, i am going to accept the patch proposed [here ](https://developer.blender.org/D7801) by @Mets.

blender-admin commented

2020-06-09 16:20:46 +02:00

This issue was referenced by ba2521b7ed

This issue was referenced by ba2521b7ed14b5deb6bb9a82a442bc85d2e05224

Alexander Gavrilov commented

2020-06-10 13:18:54 +02:00

Changed status from 'Confirmed' to: 'Resolved'

Alexander Gavrilov closed this issue

2020-06-10 13:18:54 +02:00

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