Slight arm deformation when posing

Hi everyone.
So I’ve got this issue where in the default T-Pose, the forearm/wrist is all fine and dandy, but when I pose the arm down to the character’s side, something’s “pulling” and deforming it’s topology and I can’t seem to figure it out. I’ve attached the blend file.
Thanks in advance!

male base model.blend (1.06 MB)

I am not seeing any deformation in the wrist/forearm area:

Can you post a similar image to mine so we can see the problem you are seeing please.

I presume you weigh painted this yourself rather than use “Automatic weights”, as the boundaries look too ordered when in Weight Paint Mode. Also the upper arm bone is having no effect on the upper torso, so you can fold the arm into the chest without the chest deforming.

Also, and this could be part of the problem, you have an unapplied scale of 4.581 on your armature in object mode and an unapplied scale of 0.544 on your mesh with an unapplied rotation of 90 in X. Then you don’t have the mesh with a common origin to the armature, it is offset, you can see this here:

So if you do an “Automatic Weights” parent, you get what you see above. So you need to apply these things (CTRL+A - “Location” and “Rotation and Scale” to both mesh and armature in Object mode - then you need to move the vertices to the correct location for the model, then do your parenting/weight painting again, I think that should cure these issues!

I have also noticed that your leg bones do not fit the mesh too well, you might like to look at this area also. I did what I have suggested above and it looks a lot better to me for the weight paints. As a general rule, you should use Automatic Weights and then tweak yourself using weight paint.

There are other issues with your armature, like not having a “root” bone, no links from hips to legs, etc. Can I suggest you find the “Humane Rigging” tutorials and give them a quick look, this will let you make a much better armature. The bones in the armature should be connected like they are in a real skeleton. You could also look at the Rigify armature (it’s an Add-on) to see what I mean here.

Sorry I found so many things, but if you watch these in future, you will get on much better with your modelling and rigging. Remember - do ALL edits, like rotation and scaling of the entire mesh/armature in EDIT mode, it saves a lot of problems in the long term.

Cheers, Clock.


I forgot to say that you should ideally keep a common object origin for armature and mesh, it’s not vital, but it sure stops a lot of things that could go wrong when you animate models.

Thanks for the advice! :smiley:
Here are the pics showing the “pulling”:

here is the T-Pose with no deformations.

here’s the one showing the problem. It’s subtle, but I can’t seem to get rid of it.

About the not applying the rotation and scale of the mesh, I still have the mirror, armature and subdivision modifiers on and when I applied the rot/scale it screwed everything up so I thought I’d finish rigging the mesh first.
The root bone I was also planning on adding it after the mesh was ‘properly’ rigged.

I appreciate the help and would be grateful for more :smiley:

OK - This is the order of things:

You should remove the Armature Parent from the mesh in the Object panel.

Then delete all the vertex groups in the Vertex panel.

Then delete the armature modifier, so there is no longer ANY link from mesh to armature.

Then zero the meshes origin.

Then apply rotation scale and location for both the mesh and armature in object mode.

Then go to edit mode for the mesh and move the vertices so they coincide with the armature.

Then parent the mesh to the armature with “Automatic Weights”.

You can keep the Mirror and Sub-Div modifiers in place, just make sure after the parent operation that the armature modifier is above the Sub-div in the modifiers list, it will be more efficient there as it is only moving the base vertices, not all the sub-divides.

You will see many improvements I think…

Cheers, Clock.

Ok, will do. I’ll get on it first thing in the morning (it’s 2:20am here right now).
Thanks again for the help, I’ll let you know how it goes!

Good idea! get some sleep before you start this process.

Cheers, Clock.

I did what you said and everything’s all good now! Thanks for the help Clock! :smiley:

You’re welcome - let us know how this progresses.

Cheers, Clock.