@game_engine/physics-planck

Production Planck 2D physics backend for Agent Engine.

This package implements the backend-neutral @game_engine/physics-adapter boundary used by the production headless and browser gameplay runtimes. KinematicPhysics remains available only through explicit core test/reference registries, while Rapier stays isolated as a comparison backend.

The adapter consumes plain Agent Engine physics components:

• Transform
• Velocity
• Collider
• RigidBody
• PhysicsMaterial
• PhysicsJoint

The production backend supports box collider spawn/reconfigure/despawn, layer/mask filtering, sensors, bullet CCD, distance and revolute joints, kinematic moving platforms, sorted start/stay/end collision events, grounded contact hints, and deterministic point, AABB, and raycast queries.

Use getPlanckPhysicsQueries(runtime.physics) for the public query/timing surface. The adapter retains its historical planck2d-experimental identifier for compatibility; the runtime role, rather than that stable identifier, is now production.

Do not rely on exact solver float parity across physics backends. Public traces use stable high-level fields, rounded snapshots, and deterministic ordering.

RG-05 repeats the production scene in Node headless and a real Chromium realm ten times. Performance observations use pnpm benchmark:planck; local results do not certify absolute targets until the calibrated runner is defined.