Floursack rig - how can I do that in Blender?

Recently I started to dive into rigging and animating. However I need floursack rig and I couldn’t find one for Blender, so I decided to create my own and then - if it would be good - share it on blendswap.
I got inspired by one created for maya, but I can’t get the desired effect.
Here is the video:

And what am I trying to do is in sequence 06 - 20s.

It seems that it is some bone with particular effect that deforms mesh, but whatever I tried doesn’t work well…

  • classic bone with weight creates ugly wrinkles
  • cast modifier do not pull verticles with the bone, it just push verticles from it
  • hook with proximity do mess with armature
  • best effect so far I get from using VertexWeightProximity modifier with secondary armature with stretch and maintain volume constrains, but problems starts when I want to stretch character…

Here is video of current status:

Sorry for lags. In the end is shown problem that I have.

So I wonder, do I missing something? Is there better way? :confused:
I don’t thing I can invent a better way, so in worst case there would be no stretching…

Have you played around with lattices or the mesh deform modifier? You also might want to try making driven shape keys, so that when you move or rotate a bone along a certain axis, the mesh will deform in a certain way automatically.

@Modron
Yes I was briefly playing with mesh deform and lattice, but I thought ti would be pain to maintain good deformation. I can still try to do something with it though.
About shapekeys… well I did not tried them but I am sure it will be much worse to get it right then lattices :D, but again I will try them out.
Thank you for feedback :wink:

another thought, you might also like the ‘corrective shape keys’ script, which allows you to work on a copy of a deformed mesh, and then apply the corrections in the form of a shape key to the original mesh. you can also make that a driven shape key, or key it manually.
(edit) and by ‘script’ I mean ‘add-on’. it is packaged with the current build i am pretty sure.

There used to be a rigged flour sack on BlendSwap, but it seems to have disappeared. I downloaded it quite a while ago and still have it. The license is CC-0 (public domain) so it shouldn’t be a problem for me to pass along a copy to you if you’d like to use it for reference.

It’s no where near as elaborate as what you seem to have planned, though.

And I’m unsure why the original creator removed it from BlendSwap.

PM me if you’d like me to send it to you.

At least some of that I think you could do with drivers.

I would have to have a list of all the different things it’s supposed to do (preferably with clear visual examples) to be able to figure out which things are possible and how though.

@Modron: Thanks for suggestion, will have a look at it.

@rontarrant: Yeah that is shame it was removed and thank you for the offer :wink:

@TiagoTiago: Well main thing I am trying is all in the sequence 6-20s. Other thing are not that hard to do.
If I would break it down:

  • it is the bone in the middle, one single controller
  • when it is moved vertically it moves entire mass, while it is maintaining volume at its ends
  • when moved to sides it grabs polygons with it, but its not mutually exclusive with normal middle bone
  • when pushed too far to sides it seems that there is sort of pushing points (like casting modifier) - appears on 10 second in video
  • it works on stretched character

This is what I need from it, however it is quite a challenge.

Would really need to see the file, to see what you are really doing now, before I could suggest the best way to approach this. You might need more than one controller to accomplish this. Looks like he uses one controller for stretch and bulge, I think that could be done in blender, but what do you have so far? Attach a .blend so someone can see what you have.

A talented blender user has a flour sack rig, but I’ve never looked at it, so I can’t tell you anything about it, but it might be worth looking at. His website can be found at: http://kiopaa3d.pagesperso-orange.fr/

Randy

I think I got it! I used 2 bones with stretching to pass scale value into binded bones (with maintain volume modifier).
Its not done yet, but I think it is on good way.
See more in .blend file: https://www.dropbox.com/s/ny63pqcfhrx5qyj/Floursack.blend

Thanks all for your input.

@revolt_randy
Thank you for link! It will for sure be usefull. :wink: