Problem combining soft body with armature

I’ve downloaded the Klaadu model from (it’s a creature from the Star Wars prequels.) In order to get some jiggle in the belly and neck, I created a weight-painted vertex group for the soft body modifier. It works well for the neck and belly.

The problem is that I did a simple animation where the model moves up and then down. When it gets to the bottom, the entire mesh is continuing downward a bit even though the armature has stopped. This would be fine for the torso (it gives a sense of mass.) The problem is that the legs and feet also continue downward, to the point where the feet will be passing below the ground plane. Below is a pic of the weight paint map I used.

How can I stop the rest of the body from acting like a soft body?

Steve S


If you set Goal Max to 1.0 the regions painted with the highest weight should move exactly with the armature.

With this setting i would think you have to reduce to goal weight quite a bit in your paint to have any jiggle at all.

Thanks for responding. I gave that a try but it didn’t stop it. I’ll keep tinkering with it.

Steve S

Is it acting the same as he rest of the soft body (belly and neck) or is it just a smaller amount?

I would suggest in the mean time, doing some tests with weight painting and see if you can even get it to work at all in say something like a simple ball and try some experiments until you figure it out. It will save time not having to deal with the entire rig and mesh.

It’s just moving a little bit. It’s remaining rigid and moving as a whole (except those neck and belly areas.) It’s not sloshing around like a giant water balloon. l thought that maybe I hadn’t given the torso bone enough influence in the weight painting mode, so I basically painted the entire animal red, but that still didn’t stop it.

Thanks for the tip. I’ll start with something simple to see where the problem lies.

ETA: I should point out that the problem goes away when I disable Soft Body, so that’s definitely what’s causing it.

Steve S.

Cool. Just remember to include some kind of armature in your tests.

Are there any tutorials out there on this?

And how bad is it really?

It could be that it is not perfect and you may have to cheat it. That is, live with the slight motion of the rest of the body and deal with it on a shot by shot basis. Perhaps even introduce shape keys to fix problem areas.

Just thinking realistically.

Sounds like you have the shown weight vertex group not assigned to the soft body goal.
Note the name of the group on the right hand side of the use goal button. (SB_Goal in the sample above).
Sometimes when you remove vertex groups that were created before the soft body group was created the group binding breaks. The index in the soft body data then simply points to the wrong group.
Work around :
Assign another group and then the SB_goal group again. That would fix this problem.
In blender 2.5 this bug is fixed but in 2.4xx there is no way, because the group is stored as number and not by its name.

Don’t confuse weight painting for bones with goal painting for soft bodies.
There are some other uses for vertex groups in blender e.g. marking regions where particle hair should grow.
In this case controlling the balance between animation and soft body movement.

Create a new vertex group that has a meaningful name like
It should contain all vertexes.
In this group paint the parts you want to move with the armature red ( weight value 1.0 )
use smaller values for the regions you want to jiggle.
Use the spin button right to the “Use Goal” button to select this group to control the goal.

see flag example there

Enricos Pengzilla Tut
Some years ago

Way back machine gives

I was not confusing them. :slight_smile: But thanks for the info anyway. I am well aware there are many uses, just as in LightWave. But soft body is An area I have no experience with. Hope your solutions work.

Steve S, I would take seriously bjornmose’s advice, as he coded the original softbody modules!

Thanks for the responses and sorry for the delay in getting back. The vertex group was listed in the soft body goal. (see pic below.) And I took your suggestion of deleting the old VG and creating a new one. I didn’t even paint anything onto it, just left it solid red, and it’s still doing it. I’ll try to post an animation later today.

Steve S


Well 2.5 looks like to have issues with it …
File bug reports as detailed as possible.