Skinning: Definition
Skinning is the stage in 3D character preparation where each vertex of a mesh is assigned weights corresponding to one or more skeletal joints. As the rig moves, these weights determine how much each bone influences mesh deformation—crucial for realistic bending, twisting and muscle movement.
Evolution & Techniques
Originally, skinning employed rigid binding: each vertex was fully controlled by its nearest bone, leading to sharp, unnatural deformations. In the 2000s, smooth skinning algorithms—such as linear blend skinning (LBS) and dual quaternion skinning (DQS)—allowed vertices to interpolate influences from multiple bones, reducing volume loss at joints. Artists refine results via:
- Weight Painting: Manually adjusting influence maps to fix problematic deformations around shoulders, hips and elbows.
- Corrective Blend Shapes: Adding custom mesh shapes that activate at extreme poses to preserve surface detail.
- Muscle Systems: Procedural or simulation-based modules that mimic underlying anatomy for lifelike motion.
Skinning: Pipeline Integration
After rigging and skinning, characters undergo animation tests—T-poses, A-poses and range-of-motion exercises—to identify and correct skinning artifacts. Iterative feedback between riggers and modelers ensures mesh topology supports even weight distribution.
Skinning: Trivia
- Some studios automate skinning with machine-learning tools that predict optimal weight maps from scanned anatomy.
- In hand-drawn 2D CGI hybrids, “skinning” can refer to painting over motion-captured skeletons to generate clean line art frames.