Jaw constraint causes issues for ERC

[Maneki]

I was wondering why my rig suddenly has a displaced lower jaw and lip bones. When I easy imported just FACs and masculine morphs (especially the head) and then adjust the rig, it displaces the bones on G9. I tried manually importing the FACs where the constraint doesn’t get created apparently, and there it worked. It’s just a guess that the jaw constraint is the evil but a very strong one. Is there a way to fully reset a rig? I put a lot of time into setting up this character and now it has this issue. :/

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[Maneki]

I figured out how to fix it at least. I just had to set the X-axis of the tail in edit mode to 0. Apparently the x-axis gets displaced with ERC and those constraints/drivers.
edit: What is the purpose of those constraints? Because when I manually import the FACS as custom shapes, those constraints don’t get created but every FACS shapekey seems to work just fine?

[Maneki]

This issue is exclusively to easy import it seems. When I import the character without any morphs and then import the FACS category (not custom shapes), this issue doesn’t appear either.

[Alessandro Padovani]

Commit 1e23571.

@Maneki. I can’t reproduce the issue, so I guess this is resolved in the last commit. Let us know so we can close.

my steps:

1. in daz studio load G9 and mark the masculine/feminine morphs as favorites
2. in blender set ERC as armature in the global settings
3. easy import G9 with “daz favorites” and “transfer to meshes”
4. check the masculine/feminine morphs with “morph armature“, works fine here

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[Thomas Larsson]

I cannot reproduce the problem either, but I have an idea what might have happened. Blender’s way of specifying bone orientation has a problem with bones that are parallel to the global Y axis. If the local X axis points to the left, the roll angle is 0 degrees if the bone tilts slightly upwards, and 180 degrees if it tilts downwards. If an ERC morph changes the rest pose of the face bones slightly, local X may jump from left to right, because the morph doesn’t change the roll angle. Then the face bones might start moving in the wrong direction.

Or perhaps it is something else. This shouldn’t be a problem for the jaw bone which always tilts down.

[Maneki]

I’ll check it later today with the newest dev version.

[Maneki]

The issue still exists. It’s important to follow the steps (I used Blender 4.0.2):

• Load a G9 WITH FACs during the easy import process
• Then go to custom morphs and import Base G9 masculine Head (It has to be a head morph, body morphs don’t cause this issue
• Activate Auto Morph Armature, select the rig and then press back on the timeline to quickly adjust the rig
  => the bones get dislocated

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If you do all these steps but replace the first one with the easy import by importing the FACs after easy import on the daz importer UI, the problem doesn’t seem to appear.

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[Alessandro Padovani]

Yes I can reproduce the issue. If you use daz favorites instead of custom morphs then everything works fine, as my steps above. So it seems the issue is related to importing custom morphs.

p.s. In general be aware that loading custom morphs by hand can be tricky, you never know the dependencies. Using daz favorites is safer and works better in most cases, that’s indeed why daz favorites were introduced to simplify custom morphs.

[Maneki]

I don’t think it’s related to custom morphs necessarily. Like I said, the issue doesn’t appear when the FACS get loaded after easy import with the FACS tab.

[Thomas Larsson]

Fixed in last commit, I think. If bones have already been made posable, new drivers are added to the already driven bones instead of the free bones. This is right for normal morphs but not for erc morphs.

[Alessandro Padovani]

Commit d83e9f0 works fine here, thank you for the fix. If Maneki has nothing to add we can close as resolved.

[Maneki]

The issue seems to be solved now, thank you!

[Maneki]

Fixed.