A skeletal rig is the hierarchy of bones and control structures bound to a 3D model that allows it to be posed and animated. Each bone influences nearby vertices through skinning weights, so that rotating or translating a bone deforms the surrounding mesh in a controlled way. Rigs typically combine forward and inverse kinematics with control handles, enabling animators to drive complex character motion from a compact set of controls.
- A skeletal rig is the bone hierarchy and control system bound to a 3D mesh, produced during 3D Modelling to make a model posable and animatable.
- It deforms the Polygon Mesh through skinning weights and is the foundation for Character Animation and general Animation.
- Rigs combine Inverse Kinematics with control handles so animators can drive a Character Model from a small set of controls.
Definition extended
- A rig is built once and reused across many shots, separating the slow craft of setup from the iterative craft of animating.
Overview
- Rigging sits between modelling and animation in the production pipeline.
- Bones form a parent-child hierarchy; moving a parent bone carries its children with it, mirroring real anatomy.
- Skinning binds mesh vertices to bones with weights that determine how much each bone influences each vertex during deformation.
- Control objects expose the rig through intuitive handles, hiding the underlying joint chains from the animator.
- Forward kinematics rotates joints directly, while inverse kinematics solves joint angles to reach a target, which is essential for feet, hands, and ground contact.
Mechanisms
- Bone hierarchy — a tree of joints that transmits transforms from root to extremities.
- Skinning weights — per-vertex influences that blend bone transforms into smooth deformation.
- Forward and inverse kinematics — complementary ways to pose joint chains.
- Control rig — handles, constraints, and drivers layered over the raw skeleton.
- Blend shapes — corrective and expressive deformations that supplement bone-based motion.
Applications
- Character animation for games, film, and immersive experiences.
- Retargeting Motion Capture data onto digital characters.
- Procedural and physics-driven secondary motion such as cloth and hair.
- Real-time avatars in metaverse and spatial-computing contexts.