Baking bones with visual keying produces incorrect result #81302

New Issue

Jay Doshi · 2020-09-29T18:22:36+02:00

Jay Doshi commented

2020-09-29 18:22:36 +02:00

System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: GeForce GTX 970/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 451.48

Blender Version
Broken: version: 2.90.1, branch: master, commit date: 2020-09-23 06:43, hash: 3e85bb34d0
Worked: Never (2.80+)

Short description of error
Baking bones with visual keying produces incorrect result. See following images:

Pose before baking:

Pose after baking:

There is slight difference in bone positions.

Brief description of rig itself:
First 3 layers are bones with no animation, only constraints. Layer 0 has bones where baking produces incorrect result. Layer 22 has control bones that are animated and control this whole rig.

Exact steps for others to reproduce the error

#81302.blend

Open #81302.blend
Bake Action - check Visual Keying, Clear Constraints, Overwrite Current Action
Baked action will be incorrect

Here is fille with complete rig:
Rig_Export_Error_Blend File.zip

**System Information** Operating system: Windows-10-10.0.19041-SP0 64 Bits Graphics card: GeForce GTX 970/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 451.48 **Blender Version** Broken: version: 2.90.1, branch: master, commit date: 2020-09-23 06:43, hash: `3e85bb34d0` Worked: Never (2.80+) **Short description of error** Baking bones with visual keying produces incorrect result. See following images: Pose before baking: ![untitled.png](https://archive.blender.org/developer/F8982723/untitled.png) Pose after baking: ![untitled2.png](https://archive.blender.org/developer/F8982726/untitled2.png) There is slight difference in bone positions. Brief description of rig itself: First 3 layers are bones with no animation, only constraints. Layer 0 has bones where baking produces incorrect result. Layer 22 has control bones that are animated and control this whole rig. **Exact steps for others to reproduce the error** [#81302.blend](https://archive.blender.org/developer/F8982755/T81302.blend) - Open `#81302.blend` - Bake Action - check Visual Keying, Clear Constraints, Overwrite Current Action Baked action will be incorrect Here is fille with complete rig: [Rig_Export_Error_Blend File.zip](https://archive.blender.org/developer/F8936628/Rig_Export_Error_Blend_File.zip)

Jay Doshi commented

2020-09-29 18:22:36 +02:00

Added subscriber: @netricsa

Richard Antalik commented

2020-10-07 15:08:12 +02:00

Added subscriber: @iss

Richard Antalik commented

2020-10-07 15:08:12 +02:00

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

Richard Antalik commented

2020-10-07 15:08:12 +02:00

I see quite a bit of errors when I open provided file. Such complex files may be quite time consuming to debug as well. Can you simplify file to maximum possible extent to demonstrate the issue? Or is this really problem only with complex files?

Jay Doshi commented

2020-10-07 15:22:49 +02:00

This problem is persisting with complex ones i've noted other one time too...so for this there's 3 layers of dependency on parenting
1 - base which is deform (which is totally child constraint of target bones layer) - and no other constraints to keep it clean
2 - target bones which are affected by MCH
3 - MCH bones (involves IK) - which are affected by controllers

so when i bake the base deform only, it doesn't bake correctly only where the rig is affected by 3 layers i.e. on the tube attached to gun and back of the character.

but, if there are 2 layers on other parts of the body ( Deform < Target) baking works well

I was getting different results on deform of that tube bones when i parented it to "Palm" vs " spine" (none of which were correct)

If I'm not wrong, the baking should happen globally - as is on the bones?

Also, i think the error might be for stating missing plugins as everything in the file has been cleaned up (no orphan data as such)

This problem is persisting with complex ones i've noted other one time too...so for this there's 3 layers of dependency on parenting 1 - base which is deform (which is totally child constraint of target bones layer) - and no other constraints to keep it clean 2 - target bones which are affected by MCH 3 - MCH bones (involves IK) - which are affected by controllers so when i bake the base deform only, it doesn't bake correctly only where the rig is affected by 3 layers i.e. on the tube attached to gun and back of the character. but, if there are 2 layers on other parts of the body ( Deform < Target) baking works well I was getting different results on deform of that tube bones when i parented it to "Palm" vs " spine" (none of which were correct) If I'm not wrong, the baking should happen globally - as is on the bones? Also, i think the error might be for stating missing plugins as everything in the file has been cleaned up (no orphan data as such)

Jay Doshi commented

2020-10-07 15:58:06 +02:00

Apologies for this might seem confusing...I'll post with video and images with detailed explanation in some time

Jay Doshi commented

2020-10-07 16:50:42 +02:00

This comment was removed by @netricsa

*This comment was removed by @netricsa*

Richard Antalik changed title from ~~Unable to bake slight complex rig correctly~~ to Unable to bake rig correctly

2020-10-08 18:12:22 +02:00

Richard Antalik commented

2020-10-08 18:12:22 +02:00

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

Richard Antalik commented

2020-10-08 18:12:58 +02:00

I must have seen some different errors, perhaps even from different file, sorry for that. There are still 4 warnings, but resolving them doesn't help.

I was able to simplify this rig a bit after you explained how it works, but I wasn't able to identify the issue though.

I must have seen some different errors, perhaps even from different file, sorry for that. There are still 4 warnings, but resolving them doesn't help. I was able to simplify this rig a bit after you explained how it works, but I wasn't able to identify the issue though.

Sybren A. Stüvel commented

2020-10-12 14:51:21 +02:00

Added subscriber: @dr.sybren

Sybren A. Stüvel commented

2020-10-12 14:51:21 +02:00

Changed status from 'Confirmed' to: 'Archived'

Sybren A. Stüvel closed this issue

2020-10-12 14:51:21 +02:00

Sybren A. Stüvel self-assigned this 2020-10-12 14:51:21 +02:00

Sybren A. Stüvel commented

2020-10-12 14:51:21 +02:00

Thanks for the report. Unfortunately the scenario described is too time consuming for us to track down, we require the bug reporter to narrow down the problem.

Normally .blend files can be simplified by removing most objects and disabling settings, until the problem reveals itself more clearly.

If there are many steps to reproduce the problem, please attach a .blend file saved right before the bug occurs, so only a few steps are needed to trigger the bug.

Thanks for the report. Unfortunately the scenario described is too time consuming for us to track down, we require the bug reporter to narrow down the problem. Normally .blend files can be simplified by removing most objects and disabling settings, until the problem reveals itself more clearly. If there are many steps to reproduce the problem, please attach a .blend file saved right before the bug occurs, so only a few steps are needed to trigger the bug.

Richard Antalik changed title from ~~Unable to bake rig correctly~~ to Baking bones with visual keying produces incorrect result

2020-10-12 16:35:32 +02:00

Sybren A. Stüvel was unassigned by Richard Antalik

2020-10-12 16:35:32 +02:00

Richard Antalik commented

2020-10-12 16:35:32 +02:00

Changed status from 'Archived' to: 'Confirmed'

Richard Antalik reopened this issue

2020-10-12 16:35:32 +02:00

Jay Doshi commented

2020-10-12 22:40:48 +02:00

Ah true true.. sorry will keep that in mind too.. i think the file is re-uploaded by Richard which is simplified .. will remove my previous comment which was kind of confusing

Jay Doshi commented

2020-10-13 09:53:27 +02:00

So after some digging, I think the problem lies in the way it's baked :

It correctly removes the constraints on the Deform bones ("Copy Transforms"), but then parenting is followed i.e. it's affecting the scale of parent (in the hierarchy) on the child (even with offset)

After the baking, the bone scale and position should be absolute - It should counter the scale as per the visual transform

What worked but not the best solution: Remove parents from all deform bones and bake.

If there's some complex rig structure, flattening the hierarchy may not be the best thing with many bones.

So after some digging, I think the problem lies in the way it's baked : It correctly removes the constraints on the Deform bones *("Copy Transforms")*, but then parenting is followed i.e. it's affecting the scale of parent *(in the hierarchy)* on the child *(even with offset)* After the baking, the bone scale and position should be absolute - It should counter the scale as per the visual transform What worked but not the best solution: Remove parents from all deform bones and bake. If there's some complex rig structure, flattening the hierarchy may not be the best thing with many bones.

Sybren A. Stüvel commented

2020-10-16 15:07:14 +02:00

Even the simplified example file is far from minimal. The existing animation is hidden in the dope sheet (by having "ctrl" in the channel search box), there are invalid animation channels, and there are bone groups that may or may not be relevant, and certain relevant bone layers are hidden. I think also half the bones can be deleted while still showing the problem. To illustrate, this is what the dependency graph of this file currently looks like:

It really helps when things are properly simplified ;-)

Having said that, Visual Keying is known to be problematic, especially in the context of inverse kinematics constraints. Also see #76791.

Even the simplified example file is far from minimal. The existing animation is hidden in the dope sheet (by having "ctrl" in the channel search box), there are invalid animation channels, and there are bone groups that may or may not be relevant, and certain relevant bone layers are hidden. I think also half the bones can be deleted while still showing the problem. To illustrate, this is what the dependency graph of this file currently looks like: ![depsgraph.png](https://archive.blender.org/developer/F8999591/depsgraph.png) It really helps when things are properly simplified ;-) Having said that, Visual Keying is known to be problematic, especially in the context of inverse kinematics constraints. Also see #76791.

Sybren A. Stüvel commented

2020-10-16 15:07:39 +02:00

Closed as duplicate of #76791

Sybren A. Stüvel closed this issue

2020-10-16 15:07:39 +02:00

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Baking bones with visual keying produces incorrect result #81302