Rigify - Adding bone on wrist not follow forearm twist fully

Artistic Support Animation and Rigging
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1

I’m trying to add a extra bone for a zipper I have on the sleeve of my character. I am using basic.super_copy which is a child of the forearm.

After generating the rig and weighting the zipper when I twist the forearm the zipper doesn’t quite follow. It lags behind a bit, to test out I made a cube which I have done a child-of constraint just to DEF-forearm.001 just to check and it lags behind as well. The zipper body is fully weighted to DEF-forearm.001, so I tried weighting the zipper handle fully to it as well and it works.

I just can’t get my bone to follow the twist. I am not sure if there is some constraint that’s giving the extra rotation or not.

I tested with just a cube as well and put a child-of constraint onto DEF-forearm.001 and even with that the cube is slightly off.

Zip02_Problem
Zip02_Problem620×607 38.8 KB

Zip03_Problem
Zip03_Problem824×685 83.6 KB

Zip04_Problem
Zip04_Problem1148×1042 117 KB

ZipCubwe
ZipCubwe679×583 190 KB

No idea what’s causing it. Client is already happy with the model I gave them although I ended up making the zipper handle flat against the sleeve.

But this is something I still want to figure out for myself. Actually have a similar issue for the shoe laces which is probably the same situation this.

Thanks

2

I suspect that too. Go to pose mode and check what constraints are assigned to the bone. If there are constraint that copy a location or rotation etc of another bone then check the settings and behaviors of those bones. If there are no constraints then check the parent bone, and so on. Is the parent bone actually even rotating, or is the rotation done with just bendy bone segments? :thinking:

3

Thank you,

That worked, if I put the bendy bones segments amount to 1 it was on 10 from rigify the extra rotation disappears. I thought it must have been something outside of the normal joint chain doing it.

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It has me wondering now though. What if I want to have the zip follow it after the bendy bone stuff cause I can see some good uses cases for it although having it without is fine for my current client.

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I’m not much of a rigger so don’t get too much exposure to it.