SkinKit: One-Click Weights for VRoid, VRM and FBX Avatars (Blender Add-on)

Select the armature and the meshes, press Auto Skin. Body, clothes, hair, shoes, backpacks and gadgets get clean skin weights for the deform bones, ready to pose and animate.

SkinKit works where Blender's With Automatic Weights gives up: holes, separate parts, layered clothing, hidden skin under clothes, and rigs imported from VRoid, glTF or FBX with bone tails pointing the wrong way. No "Bone Heat Weighting: failed to find solution". Every vertex gets weights.

• Clothes copy the weights of the skin under them, so they move with the body
• Hair, skirt and ear chains weight only what hangs from them
• Buttons, buckles, eyes and earrings move as one piece
• Left and right stay apart, even where the thighs touch
• 4 bones per vertex by default, normalized, for Unity, Unreal and VRChat
• Skin Clothes to Body for a new outfit on a skinned avatar

On a VRoid avatar with hair, a backpack and a robot arm, Blender's Automatic Weights left 29,002 of 34,059 vertices without weights. SkinKit weighted every vertex in 10 seconds. About 5 seconds for a 25,000 vertex avatar on a 2 core machine. Pure Python, no GPU. Blender 4.2 to 5.2. English interface.

Good to know

• A strong starting point: faces with many small bones and touching fingers may need a few strokes of weight painting.
• Clothes are skinned, not simulated.

Included: SkinKit 1.0.1 add-on folder, 12 months of updates and e-mail support ([email protected]). Docs: https://superhivemarket.com/products/skinkit/docs Test characters in the images: VRM1 Constraint Twist Sample (c) pixiv Inc. and Seed-san by VirtualCast, Inc., both under the VRM Public License 1.0; a test human made with MakeHuman (CC0).

License: SkinKit add-on code: GNU GPL 3.0 or later. Use it for personal and commercial avatar work. The avatars you edit keep their own licenses.

Product video: https://youtu.be/oyKWVjDSCuU

AI-assisted: the add-on code was written with help from AI coding tools. Designed and tested by Meshwright in Blender 4.2 and 5.2. The store images are Blender renders.