[Rigging] Tri-joint shadow weighting
How to synchronize two layers of geometry under the deformation of a primary joint. - 11/2025 - #Skinning, Jumble
A skinning technique to fake deforming layers using Linear Blend Skinning (i.e. a unique skin cluster in Maya), useful for instance, for characters with overlapping geometry layers (e.g., body + clothing). The setup uses three sibling joints under a common parent:
- Primary deformer joint - Influences both layers simultaneously with identical skin weights, preventing interpenetration during shared deformation
- Inner layer joint - Controls the base mesh only (sibling to primary joint, stationary when primary joint moves)
- Outer layer joint - Controls the outer mesh only (sibling to primary joint, stationary when primary joint moves)
The inner and outer joints remain fixed in the hierarchy while the primary joint animates, allowing independent layer manipulation while maintaining consistent dual-layer deformation.
Key characteristics:
- Three sibling joints sharing a common parent
- Layers share identical topology and skin-weight patterns
- Prevents self-intersection during combined deformation
- Inner/outer joints stay stationary as primary joint deforms
- Preserves independent layer control
Notes
A proper way to deform multiple layers is to apply multiply deformer, such as several skin clusters (Maya), post process lattice deforamtion etc. Those are usually not supported in game engines though.
Donate
No comments