Bake Actions with constraints results in bad rotations #127312

New Issue

Robin Karlsson · 2024-09-08T16:12:51+02:00

Robin Karlsson commented

2024-09-08 16:12:51 +02:00

System Information
Operating system: Windows-10-10.0.22621-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 4090/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 560.94

Blender Version
Broken: version: 4.2.1 LTS, branch: blender-v4.2-release, commit date: 2024-08-19 11:21, hash: 396f546c9d82
Also tried in 4.1 with the same results.

Short description of error
When I set up an animation using empties with constraints on them and then try to bake the constraints sometimes they break down completely where their rotations are messed and no longer lined up to where they should be as can be seen in this image:

In order to make the bake action break I deliberately went in and rotated the top and bottom empties (as it seemed to work otherwise without this). I've got constraints that control the rotations so it looks like this should still work and it does until you bake it out. Obviously going in and fixing this issue manually wouldn't be too bad in this file, but I did this in order to demonstrate the problem. I've run into this issue in production with much more advanced rigs and setups where it would be much more difficult to fix up (can't share them though).

Exact steps for others to reproduce the error
I've prepared an example blend file here:
Bake_Action_bug.blend

Select the entire hierarchy named Unbaked Anims
Go to Object>Animation>Bake Action
Make sure 'Only Selected Bones' and 'Clear Constraints' are all ticked. Try ticking and unticking 'Visual Keying' without the issue getting much better either way.
Hit OK to confirm and observe the broken results.

Only way to fix it seems to be to tick the 'Clear Parents' option (along with the other options mentioned previously) but obviously ticking this will break hierarchies which would need to be maintained for my use-case.

**System Information** Operating system: Windows-10-10.0.22621-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 4090/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 560.94 **Blender Version** Broken: version: 4.2.1 LTS, branch: blender-v4.2-release, commit date: 2024-08-19 11:21, hash: `396f546c9d82` Also tried in 4.1 with the same results. **Short description of error** When I set up an animation using empties with constraints on them and then try to bake the constraints sometimes they break down completely where their rotations are messed and no longer lined up to where they should be as can be seen in this image: ![Bake_acxtion_constraint.png](/attachments/ee68ff7e-dd3e-4866-913a-93aa16f97223) In order to make the bake action break I deliberately went in and rotated the top and bottom empties (as it seemed to work otherwise without this). I've got constraints that control the rotations so it looks like this should still work and it does until you bake it out. Obviously going in and fixing this issue manually wouldn't be too bad in this file, but I did this in order to demonstrate the problem. I've run into this issue in production with much more advanced rigs and setups where it would be much more difficult to fix up (can't share them though). **Exact steps for others to reproduce the error** I've prepared an example blend file here: [Bake_Action_bug.blend](/attachments/25fa8863-672b-44a9-a6bb-0160cb5b5395) 1. Select the entire hierarchy named Unbaked Anims 2. Go to Object>Animation>Bake Action 3. Make sure 'Only Selected Bones' and 'Clear Constraints' are all ticked. Try ticking and unticking 'Visual Keying' without the issue getting much better either way. 4. Hit OK to confirm and observe the broken results. Only way to fix it seems to be to tick the 'Clear Parents' option (along with the other options mentioned previously) but obviously ticking this will break hierarchies which would need to be maintained for my use-case. ![Bake_Actions.png](/attachments/f02f105d-f98c-4adb-935b-36d802faa116)

Bake_Action_bug.blend

1.7 MiB

Bake_acxtion_constraint.png

506 KiB

Bake_Actions.png

48 KiB

Robin Karlsson added the

labels 2024-09-08 16:12:52 +02:00

Iliya Katushenock commented

2024-09-08 16:55:03 +02:00

Thanks for report, your file contains dependency cycle, please, fix this and check if this will resolve your issue.

Dependency cycle detected:
  OBpiston_top/TRANSFORM_CONSTRAINTS() depends on
  OBpiston_bottom/TRANSFORM_FINAL() via 'Track To'
  OBpiston_bottom/TRANSFORM_CONSTRAINTS() via 'ObConstraints -> Done'
  OBpiston_top/TRANSFORM_FINAL() via 'Track To'
  OBpiston_top/TRANSFORM_CONSTRAINTS() via 'ObConstraints -> Done'
Detected 1 dependency cycles

Thanks for report, your file contains dependency cycle, please, fix this and check if this will resolve your issue. ``` Dependency cycle detected: OBpiston_top/TRANSFORM_CONSTRAINTS() depends on OBpiston_bottom/TRANSFORM_FINAL() via 'Track To' OBpiston_bottom/TRANSFORM_CONSTRAINTS() via 'ObConstraints -> Done' OBpiston_top/TRANSFORM_FINAL() via 'Track To' OBpiston_top/TRANSFORM_CONSTRAINTS() via 'ObConstraints -> Done' Detected 1 dependency cycles ```

Iliya Katushenock added

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Bake Actions with constraints results in bad rotations #127312