Issue when i try to paint muscle weight, mesh is deforming


Hello there,

I am trying to implement some muscle rigging onto my character and im faced with an issue, when im trying to paint the muscle weight (via Deform->Muscle->Paint Muscle Weight), its deforming my mesh.
Ill try to explain the background more in depth.

The issue stars right here i think:
After i convert my character mesh to muscle system (Deform->Muscle->SKin Setup->Convert smooth skin to Muscle System) the root skeleton bone of my joint rig scales up to 100 on it own, along with my character mesh of course.
If at this scale i create the muscle bind it to the joints i need (in my case upper arm to elbow) and then connect it to my character, the paint works great.

However i dont want my character to be scaled at 100. So if i scale the root bone back to 1 like it should be, then do the same process, create muscle, connect it and so on, when i paint the weight for muscle, the mesh deforms like in this picture:

Im not sure why my root bone scales to 100 when i do the Deform->Muscle->Skin Setup->Convert smooth skin to Muscle System, originally is to 1.
I also tried to scale and rescale the transforms that appear in my Outliner (which also appear with a scale of 100 for some reason), the muscle and so on.

Im a beginner here and i have been having this issue for 3 days, not sure how to fix it. Any help would be greatly appreciated.


After hours of investigations and trying various things i still cannot fix the issue.

My character is ported over from Blender as a FBX and when its imported into Maya it has root joint scale of 100. Scale that i set to 1.

So when i use Deform->Muscle->Skin Setup->Convert Smooth Skin to Muscle System it rescale this root bone to 100 but not sure why…

As i said if i paint muscle weights at the scale of 100 its all okay, when i scale it down to 1 and i paint the muscle weights the mesh deforms for some reason.

Not sure what to do, i tried many things.