Skinning is the process of creating an association between a Mesh (the Skin) and a Rig. More specifically in the Skinning process we define associations for each bone of the Rig’s Skeleton to each vertex of a mesh. In practice, for a polygonal mesh character, each bone is associated only with a subset of the character’s vertices.
Portions of the character’s skin can be influenced by 2 or more bones, where each vertex of the affected area gets an influence factor to each associated Bone. This factor is also called Vertex Weight. Thus the influence of each bone on a specific Vertex is defined by its Vertex Weight.
The process of Skinning includes:
- Binding the Character to the rig in a specific Pose (basically establishing an association between the Rig and the Mesh)
- Weighting the Mesh to the Armature bones (create the Vertex Weights)
After you have modeled your mesh (Character or Attachment) the next step towards animating your work is skinning the mesh
This is basically done in 2 Steps:
- Binding: Attach the mesh to a rig
- Skinning: Define how the mesh gets influenced by the Armature’s Skeleton.
Avastar’s Skinning Tools Panel provides a convenient starting point for this work.
Cleaning up the Mesh
Ensure that the mesh does not have any implicit scale or rotation from one of its parent objects. This issue typically happens when your mesh is still parented to another object (Mesh, Rig, Empty,…) which has a scale and or rotation defined. Or when you have added scale and rotation to your Mesh Object(s) in Object mode.
If Avastar detects this issue, it displays a warning message right in the Binding Panel and it disables the binding button (button turns red).
Click the fix button in the Skinning Tools (see image) or do it manually as follows:
- Select the Mesh
- Object -> Parent -> Clear and Keep Transformation
- Object -> Apply -> Rotation and Scale
This cleanup avoids unexpected behavior and it ensures that your object can be bound to another rig without distortions.
Reposition and Bind
You prepare the binding step as follows: First you align your new mesh attachment as good as possible to the Avastar character. Then you select both the armature and the new mesh attachment:
- Go to Object mode
- Select the attachment with RMB. If you want to bind multiple new attachment at once, select all of them now (order does not matter).
- SHIFT RMB select the Avastar Armature.
Now you have selected the Rig and all mesh attachment which shall be bound to the Armature.
Note: If you are familiar with Blender, then you can simply parent the selected meshes to the armature (using Object -> Parent -> Armature Deform).
In the next step you will Bind your Meshes to the Rig