How could I rig this loose reptile skin?

Hello all,

I’m fairly new to blender and have been working my way up my very first sculpted, retopologized and rigged model (a cartoony dilophosaurus). I’m currently still fixing all the kinks and glitches with the armature and have an issue figuring out how I can get the hanging/loose skin on it’s neck.
Previously it would stretch too much when I moved the head around, so a friend suggested I add a bone and weight paint it to this section so that it preserves its shape better. This worked, however now I have to manually move/rotate the bone whenever I move the head to shape this skin appropriately. I don’t want it to stretch too much, and would like it to remain shaped like a mound even when the neck is stretched outward. Is there anything I could do? Alternate setup, any constraints perhaps?
Apologies for my poor blender vocabulary :sweat_smile:

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There is an addon called Jiggle Bones that might work. However I’ve never used it on an actual project so I can’t be certain.

that’s a nice chicken you have.

As captainkirk said you can directly use the Jiggle Bone addon. Or you can simply use 2 boxes with their physics setted to “rigid bodies” : parent a box to the head (so that box will not move). The second box will have a rigid body constraints with the first box as “target” ; so the second box will be like attached by a wire to the first box. Last, parent your fatty neck bone (with bone constraints) to the second box , so it will follow its movements submitted to physics law. This method is used to making ragdolls

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Or, maybe, you could constrain the loose bone to (partially) follow the last bone of the neck (the nearer to the head) with a ‘Child of’ constraint.
Or you could even make this bone a real child of the last bone of the neck, and partially constrain it to the head.

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Does JiggleArmature work with 2.8?

That’s a good idea. But not sure it will jiggle . If constraints 50% the loose bone will just follow the neck midway. But i remember that making some weird parenting cycles (just like cats in a village) can make some interesting results (and i’m not only talking about the kitties)

oops , seems I didnt read properly his problem … . do you want the loose bone jiggle or simply move back when moving the head ahead ?

In the second case, you have the ‘transformation’ bone constraint . Or as suggest by @sourvinos , make the bone “Child of” (bone constraints) 50% to the lower neck

Just by eye, what I would try is parenting the bone to one of the neck bones, probably the one it starts out closest to, then add a limit rotation constraint so it always stays in the same orientation. Maybe a limit distance constraint to the lower neck to pull it back slightly as it moves forward.

neck

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I was hoping to have it move back, but given that it’s loose, a jiggle would also be a neat extra.
I’ve got JA installed now

ah ok , it will jiggle under the head after all. All right

Thanks a bunch for the added GIF :smiley:

I went with this and got a somewhat decent result. I might have to tweak the weights to fix the stretching though:

Can I still add some jiggle with JA?

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just create a second neck from the dorsal up to the mouth. Problem solved

I added a bunch of distance constraints so that the loose skin bone bounces off/avoids intersecting with other bones when rotating the head. It seems to work fine now, minus some stretching that happens with the texture. Probably my fault for sculpting this model with an upright neck.
Now I’d just like to add some jiggle to it

And all good! Thought it would be harder.

Thanks a lot guys :heart:

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