[QUESTION] Rigging Fat Bipedal

#1

Hello guys, I am currently trying to rig a character which has quite big belly like this character on the video:(even bigger than this reference)

What would be the best way to rig that belly? I already have spine joints and when I bend them sideways or front, mesh is collapsing like expected. I can try to create partial joints for every single spine joint for sides and forward motion then scale them outwards when bend down but would that be the efficient way? Or I can try to put some sphere mesh into his belly then add influence to deform like a real flesh but I could not find a way to set that kind of automatic mesh deformation for the inside sphere.

#2

Hi,
You can try the following in order of “complexity”
(A) Add a leaf joint in belly. So the weighting influence is not on the spine but on the belly. This way you will have less collapsing
(B) Do a corrective deformation in the problematic pose
© Make a muscle system.

Personally, I’d try A first and for art direction, i’d do B.

#3

Hello. The best option without to dive into dynamics is to add a " fake muscle", object infulence, based on ribbon rig. Then drive the middle joint, that drive the middle of the ribbon, with some extracted matrix, so you can have driven key based on Quat. rotations to get some “auto” compensate. :)!

It’s like a ribbon spine rig, basically, but with offset pivots points so you have compression on belly.

#4

Thats exactly i’ve been trying to figure out how to do it. I thought I could use single IK chain from the bottom of the ribbon spine to the top, then use set driven keys to trigger 4 shapes (for front, back, left, right). Not sure if that’d work but I am not that expert on matrixes or have no idea about Quat so I cant try what you adviced :frowning:

#5

Off topic, but by any chance, do you have a reference on this? Interested on knowing your solution further.

#6

Think of it as prototype since I did not care about skinning at all, maybe we can improve this technique but so far this is what I could think of. ( Sorry that I had brain-freeze the moment I was looking for shape editor :smiley: )