Pivot Bone Constraint - wrong offset and pivot #72389

New Issue

TonyG · 2019-12-12T15:12:37+01:00

TonyG commented

2019-12-12 15:12:37 +01:00

System Information
Operating system: Darwin-18.7.0-x86_64-i386-64bit 64 Bits
Graphics card: Intel(R) UHD Graphics 617 Intel Inc. 4.1 INTEL-12.10.12

Blender Version
Broken: version: 2.82 (sub 5), branch: master, commit date: 2019-12-11 18:53, hash: b03066f7ee

Short description of error
The "Pivot" Bone Constraint is not working right :

offsetting the pivot moves bone in diagonal (instead of along the axis)
the resulting pivot distance is half what it should be
the offset is moving around if parent bone is rotated

Exact steps for others to reproduce the error
Open provided Blend file :

play with Pivot offset = moves bone in diagonal
rotate Bone 2 = wrong pivot (should be at the bone's tip, not in the middle of nowhere)
rotate Bone 1 = wrong parenting (offset shifts)
PivotBoneConstraint_wrong.blend

Videos
Bug 1 : diagonal offset
Offset_diagonal.mp4

Bug 2 : wrong pivot
Wrong_pivot.mp4

Bug 3 : wrong parenting
Wrong_parenting.mp4

Bonus : SETUP
create two parented but unconnected Bones
add a "Pivot" Bone Constraint (set targent to previous Bone, and Head/Tail position to 1)
Setup.mp4

**System Information** Operating system: Darwin-18.7.0-x86_64-i386-64bit 64 Bits Graphics card: Intel(R) UHD Graphics 617 Intel Inc. 4.1 INTEL-12.10.12 **Blender Version** Broken: version: 2.82 (sub 5), branch: master, commit date: 2019-12-11 18:53, hash: `b03066f7ee` **Short description of error** The "Pivot" Bone Constraint is not working right : 1) offsetting the pivot moves bone in diagonal (instead of along the axis) 2) the resulting pivot distance is half what it should be 3) the offset is moving around if parent bone is rotated **Exact steps for others to reproduce the error** Open provided Blend file : 1) play with Pivot offset = moves bone in diagonal 2) rotate Bone 2 = wrong pivot (should be at the bone's tip, not in the middle of nowhere) 3) rotate Bone 1 = wrong parenting (offset shifts) [PivotBoneConstraint_wrong.blend](https://archive.blender.org/developer/F8212812/PivotBoneConstraint_wrong.blend) **Videos** Bug 1 : diagonal offset [Offset_diagonal.mp4](https://archive.blender.org/developer/F8212838/Offset_diagonal.mp4) Bug 2 : wrong pivot [Wrong_pivot.mp4](https://archive.blender.org/developer/F8212841/Wrong_pivot.mp4) Bug 3 : wrong parenting [Wrong_parenting.mp4](https://archive.blender.org/developer/F8212842/Wrong_parenting.mp4) Bonus : SETUP create two parented but unconnected Bones add a "Pivot" Bone Constraint (set targent to previous Bone, and Head/Tail position to 1) [Setup.mp4](https://archive.blender.org/developer/F8212827/Setup.mp4)

TonyG commented

2019-12-12 15:12:37 +01:00

Added subscriber: @antoine.grasset

Jacques Lucke commented

2019-12-29 15:46:31 +01:00

Added subscriber: @JacquesLucke

Jacques Lucke commented

2019-12-29 15:46:31 +01:00

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

Jacques Lucke commented

2019-12-29 15:46:31 +01:00

I can confirm that issue, could not find any reason for this behaviors yet. However, it seems that this constraint has known issues. It's tooltip contains (buggy). Not sure if I've ever seen this in Blender ^^

I can confirm that issue, could not find any reason for this behaviors yet. However, it seems that this constraint has known issues. It's tooltip contains `(buggy)`. Not sure if I've ever seen this in Blender ^^

Sybren A. Stüvel commented

2020-01-14 11:59:24 +01:00

Added subscriber: @dr.sybren

Sybren A. Stüvel commented

2020-01-14 11:59:24 +01:00

Marking as Known Issue, as nobody is actively working on this constraint for a long time. The manual also doesn't show what exactly is buggy, or how it should behave in the first place.

Marking as Known Issue, as nobody is actively working on this constraint for a long time. The [manual](https://docs.blender.org/manual/en/dev/animation/constraints/relationship/pivot.html) also doesn't show what exactly is buggy, or how it should behave in the first place.

Dmitry commented

2020-06-08 17:24:14 +02:00

Added subscriber: @DmitryKondratkov

Dmitry commented

2020-06-08 17:24:14 +02:00

Dear developers! I want to use Blender for animation but this is impossible without possibility to animate pivot position. Can we hope that you can fix this in the near future? Thanks in advance.

Beorn Leonard commented

2021-05-06 18:29:36 +02:00

Added subscriber: @BeornLeonard

Beorn Leonard commented

2021-05-06 18:33:22 +02:00

Would be great to have this one working, for many reasons. Mainly it would simplify many rigs which currently have to use many bones to achieve the same result, and would make modifying predefined rigs from rigify much much easier.

Right now it seems to only work under laboratory conditions (2 isolated bones which are both pointing upwards).
Is there any hope of getting this potentially very useful constraint to work?

Would be great to have this one working, for many reasons. Mainly it would simplify many rigs which currently have to use many bones to achieve the same result, and would make modifying predefined rigs from rigify much much easier. Right now it seems to only work under laboratory conditions (2 isolated bones which are both pointing upwards). Is there any hope of getting this potentially very useful constraint to work?

Yann Kervran commented

2022-10-13 19:31:47 +02:00

Added subscriber: @YannK

Philipp Oeser removed the

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Pivot Bone Constraint - wrong offset and pivot #72389