Joints

A joint constrains two rigid bodies relative to each other.

Joints are authored in ordinary project source through @react-three/rapier — the engine ships the PhysicsAdapter observation protocol, not a second physics authoring format. A component holds refs to the two bodies and calls the appropriate joint hook.

The five joint types.

Types

Hook	Constraint
useFixedJoint	Welds two bodies rigidly together.
useRevoluteJoint	A hinge around one axis.
usePrismaticJoint	A slider along one axis.
useSphericalJoint	A ball-and-socket.
useRopeJoint	Limits the bodies to a maximum separation.
useSpringJoint	A soft constraint with rest length, stiffness, and damping.

Each hook takes refs to two RigidBody instances plus the native tuple documented by @react-three/rapier: local anchors, and then the joint-specific frames, axis, limits, length, stiffness, or damping. The returned ref is Rapier’s own impulse-joint object.

Need a motor or custom constraint?

Use the returned Rapier joint or useRapier() and call Rapier directly. vgai adds no joint schema or wrapper around it.

See also

• Rigid bodies — the bodies a joint connects.
• Worlds and roots — why the JSX is the document.