Depsgraph doesn't add the correct relations to a Bone driver unless it is recreated from scratch #121874

New Issue

Sebastian Parborg · 2024-05-16T15:49:27+02:00

Sebastian Parborg commented

2024-05-16 15:49:27 +02:00

System Information
Operating system: Gentoo Linux
Graphics card: AMD Radeon Vega Frontier Edition

Blender Version
Broken: Since a least Blender 4.1, but I don't think this is a new issue.

Short description of error
It seems like depsgraph doesn't correctly add all the needed dependencies to certain bone drivers.
Even after using the "Update dependencies" button in the driver editor.

It also seems like Cycles takes the result of the depsgraph viewport evaluation instead of the render evaluation for final animation renders.

Exact steps for others to reproduce the error

Open the attached example .blend file
Step back and forth in the timeline. Note that the shape of the mesh or the bendy bones stays the same.
If you render the animation (ctrl f12), notice that the resulting shape is deformed strangely:
If you untick "Disable in Renders" for the ctrl collection it now renders correctly:

You can also see this happen in the viewport playback if you enable "Disable in Viewport" for the ctrl collection.

Cycles funkyness

While testing this out I noticed that Cycles doesn't have any issues with "Disable in Renders". But if you flip it around so you have the ctrl collection be "Disable in Viewport" but not "Disable in Renders", then Cycles has the same issue as Eevee/Workbench.

Seems like Cycles is using the viewport evaluation and not the render evaluation? Probably an other bug that this issue showcases, right?

Further analysis

I did some more digging and noticed that the two drivers in the scene does not have the same amount of depsgraph in/out dep arrows in the debug renders:

Note that the "ease out" driver has three "in" arrows and one "out" while the problematic "ease in" driver only as two "in" arrows and one "out" arrow.

If I manually delete the driver and recreate it from scratch (not copy/pasting it), things starts working again and the new depsgraph debug export now shows that the "ease in" driver now has the same in/out arrows as the other driver:

Note that it now correctly is linked to ctrl_upWaistTube_BBoneSubA_001_L, while in the first image it was not.

To me it seems weird that this was missing in the first place and even more weird that the "Update dependencies" button in the action editor did not solve this issue. However, deleting and recreating the driver from scratch does make depsgraph derive the correct relationships.

Here is the driver in question for reference:

**System Information** Operating system: Gentoo Linux Graphics card: AMD Radeon Vega Frontier Edition **Blender Version** Broken: Since a least Blender 4.1, but I don't think this is a new issue. **Short description of error** It seems like depsgraph doesn't correctly add all the needed dependencies to certain bone drivers. Even after using the "Update dependencies" button in the driver editor. It also seems like Cycles takes the result of the depsgraph viewport evaluation instead of the render evaluation for final animation renders. **Exact steps for others to reproduce the error** 1. Open the attached example .blend file 2. Step back and forth in the timeline. Note that the shape of the mesh or the bendy bones stays the same. 3. If you render the animation (ctrl f12), notice that the resulting shape is deformed strangely: ![image](/attachments/3d9a3d50-8ec0-4d63-996e-698da6189e41) 4. If you untick "Disable in Renders" for the `ctrl` collection it now renders correctly: ![image](/attachments/8171276f-774b-4427-8acf-38c0f36ab850) You can also see this happen in the viewport playback if you enable "Disable in Viewport" for the `ctrl` collection. ## Cycles funkyness While testing this out I noticed that Cycles doesn't have any issues with "Disable in Renders". But if you flip it around so you have the `ctrl` collection be "Disable in Viewport" but not "Disable in Renders", then Cycles has the same issue as Eevee/Workbench. Seems like Cycles is using the viewport evaluation and not the render evaluation? Probably an other bug that this issue showcases, right? ## Further analysis I did some more digging and noticed that the two drivers in the scene does not have the same amount of depsgraph in/out dep arrows in the debug renders: ![image](/attachments/53d0d61f-8039-4299-9745-9303f642956b) Note that the "ease out" driver has three "in" arrows and one "out" while the problematic "ease in" driver only as two "in" arrows and one "out" arrow. If I manually delete the driver and recreate it from scratch (not copy/pasting it), things starts working again and the new depsgraph debug export now shows that the "ease in" driver now has the same in/out arrows as the other driver: ![image](/attachments/98ee74e0-eb3d-4fec-bd8a-82788c4d90e4) Note that it now correctly is linked to `ctrl_upWaistTube_BBoneSubA_001_L`, while in the first image it was not. To me it seems weird that this was missing in the first place and even more weird that the "Update dependencies" button in the action editor did not solve this issue. However, deleting and recreating the driver from scratch does make depsgraph derive the correct relationships. Here is the driver in question for reference: ![image](/attachments/6d1c206c-13d4-45ed-abd3-34ecd185b187)

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