Bone rotation changes mesh size

Support Animation and Rigging
1

Hello
I tried to make a simple rig built out of 3 bones, the root one(required for source), a connector one(I don’t define it) and the swinging arm one. Now when I try to rotate the swinging arm the arm changes its size and does not rotate properly

http://i.imgur.com/NLmaw.png
NLmaw.png810×444

Can anyone shed some light on this?

2

Check which vertices are connected to which bone…

Sometimes easiest to see using weight paint mode and just changing vertex groups.

3

Its an action figure so the limbs are separated from the body, and the one in the pic is assigned to that bone

4

Can you post a sample file?

How are you “assigning the bone”?. Simple parenting to bone would suffice in this case. Use Ctrl-p to set up the parent relationship. If you are using the the object relation panel it will apply scale for the relationship… which is my hunch on your prob.

5

Hummm

Try checking “preserve volume” in the Armature modifier, almost 100% of the time the bad deformations occur because of that.

6

I’m with batFINGER on this one. If you are using an armature modifier on the mesh, check the scale of the mesh, it should be 1, 1, 1. CTRL-A -> apply scale will reset the scale to 1, 1, 1. But since it’s a separate mesh, parenting it to the bone is easiest.

Randy