View Full Version : Rigging a non-limbed character (Bar of Soap)

07 July 2007, 05:29 PM

I have recently been asked to put together a pre-viz for an ad agency (which is great) which involves a little dude (bar of soap) as the main character. My task is to animate the little guy dancing around the bath tub, moon walking, back spinning, slipping & sliding etc for the pitch. However, I am finding it awfully difficult, not being a rigger by nature, to rig this little guy.

My challenge: Though the character does not have any limbs, I need to provide characteristics you would find in a human (legs, arms, head and torso) in the animation sequence of him dancing though keeping true to the model of the bar of soap.

My progress: (crash and burn) I have created a rudimentary rig and have simply done a soft bind to the model, but am getting poor flexibility in the model i.e deforming “yukiness” on the legs and arm areas when I’m animating a step or stretch. I know IK’s can help in nice follow through when animating legs and arms however, my attempt at that has resulted in further “yukiness” and find myself not knowing what to do with it all.

My plea: I know this is a real newbie post and probably not worth a Riggers time to look at however, I have tried finding a tut that provides rigging such a character to no avail. I’m finding that this is a kind of a unique case, (I think) a non-biped that needs to act out a bipeds animation - I was hoping some of you guys who respond to all the great posts could help me out in any way.

Any help would be most gratifyingly and humbly appreciated!

P.S – I know you’re asking yourself: If you can’t rig a character to save your life why are you taking on such a task – are you thick in the head? Answer is Yes, I am thick in the head, so I have been told but that aside I was part of a team of 2 (1. modeller/ lighter & 2. Rigger/ Animator) and now I am a team of one, guess which one left?


Thanks in advance.


07 July 2007, 07:25 PM
This looks like the flour sack animation that is taught in your very first animation class. The idea is that if you can animate a dumpy flour sack, you can animate anything
Link (

Try to think of it less as a bipedal char. (which is what your rig looks like) and more as a bar of soap. Put joints where u need areas to move, bind, and use controllers to animate the bones.
because of the simple layout of your geo, painting weights should be a sinch.

Do some research, try a few things out, and then youll find your questions get more specific.
Dont know if this helps but at least its a point in the right direction.

07 July 2007, 11:35 PM
Hey Scott

Thanks for your reply, and yes it does help :). I appreciate you sending the link through, I never did have that class on "Animating a Flour Sack" during my schooling, but I am now wishing I did.

I will continue to research this (animating a flour sack) and perhaps ill find something that will help. My main issue here is the rigg setup and not the animation I guess. Assuming that my character will be doing lets say a basic walk cycle, Im not sure if the skeleton setup im using is good enough for what I'd like it to do.

In any case, I will keep trying and hoping I can get a little further with this or perhaps some good tips from the guys here on CGS.


07 July 2007, 03:10 AM
Something else you could try for a little more control is add another layer of deformation on top of your bone setup is create a lattice, or multiple lattices, around your soap guy. Then create some clusters out of the lattice points and adjust the weights in the component editor so you have a smooth falloff, and so then if you are not happy with the way your bound soap is looking, you can use these clusters to move the geometry around some more.

If you wanted to get really fancy you could also set up a squashy stretchy Ik in the middle. I don't know if you have the book, but there is a tutorial in Chapter 2 of '3D Advanced Rigging and Deformations' (in the 'Inspired' series). But what my animation teachers would probably say is the old 'give it a KISS--Keep It Simple, Stupid'..

07 July 2007, 04:37 AM
Hi Amy,

Thanks for your "outside the square" (for me at least) suggestions. After reading your post I did a little research and I think that's exactly what's missing on my rig :)

I will have a go at it tonight and post back how I went.

Thanks again.


P.S Big fan of K.I.S.S .... not the band that much but Keeping It Simple :buttrock:

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