Rapier Physics in Three.js

What this builds

A production physics integration layer that couples a Rapier WASM physics world to a Three.js scene graph, with fixed-timestep simulation, rigid body/collider lifecycle management, transform sync from physics to render, debug wireframe visualization, and full cleanup on teardown. The finished system lets you tag meshes as dynamic/kinematic/fixed, attach collider shapes, and have physically-driven motion with zero per-frame allocation.

• Rapier WASM world initialized asynchronously with proper await pattern
• Fixed-timestep accumulator decoupled from render frame rate
• Rigid body + collider creation from Three.js mesh geometry
• Per-frame transform sync: physics world -> Three.js Object3D positions/rotations
• Character controller (KinematicCharacterController) for player-like movement
• Joints (revolute, prismatic, spherical, fixed) between bodies
• Debug wireframe renderer showing collider shapes
• Full disposal: bodies, colliders, joints, and the world itself