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Mirroring legs joint orientation differences

I have a quadruped rig I rigged 1.5 years ago using mGear 4.0.9.
And earlier this month a feature request came through that had me needing to rebuild it. Several issues came up.

First of which being I needed to update the guides, since a straight build produced a warning the guide is out of date. v1 of the rig, I used the leg_3jnt component, but set it to have 0 divisions in the limbs. New mGear version fails to update the guide with div set to 0.
I swapped the leg component to use the newer EPIC_leg_3jnt, which allows 0 twist joints.
Updating guide now worked as expected.

The rig built, however had a few key differences which I now need to iron out.

  1. Old leg joint hierarchy (leg_3jnt_01 component) has an end_jnt the new one doesn’t. This is easy enough to fix in post, but wondering if there’s a fix that would save me that trouble.
  2. Mirrored side also mirrored joint orientation, so previously exported animations look jacked. Anyway to mirror so joint orientation doesn’t change? Old rig had the legs of both sides have X point down the joint, where as the new rig with the EPIC_leg_3jnt component has the mirrored leg have X point up the joint. negative X is down the joint.

Old:


New:

Thank you in advance for any advice!

There is a fundamental difference in the two 3leg components.
EPIC_leg_3jnt_01: joint orientation has X mirrored.
leg_3jnt_01: Joint X direction is the same when mirroring.

Is this a bug or by design? Any advice on how to get one to behave like the other?

Why not rebuild the rig in 4.0.9?

I don’t know the specifics, but the epic components were designed to more closely mimic the skeletons you find in Mannequin, etc. Not to be compatible with older Shifter components.

I don’t think the differences between the two leg_3jnt components changed between versions. It’s just in the older version of mGear I could build the non epic component with 0 twist joints and now I can’t.

I would expect the two components that do the same thing: build a three joint leg chain, orient the joints the same way.

They don’t do the same thing. The epic components were built for UE. The original Shifter rig had no such goal.