physics

Register the physics extension when creating the app with createApp({ extensions: [physics()] }), then add a collider component to make an entity solid and a Rigidbody to make it move. The simulated pose is read from entity.transform like any other node.

Add a collider with isTrigger set to true and attach a script implementing onTriggerEnter(trigger: TriggerEvent). Trigger events carry both entities, making them the documented mechanism for gameplay reactions.

Yes, the simulation runs on a null-engine scene with no GPU, and under Node the Havok WASM binary is read from the installed @babylonjs/havok package. However, MeshCollider requires a GPU app and reports IGX-0906 in headless mode.

Physics queries need at least one completed fixed step because Havok builds its broadphase during the first step. Step the app once after building the scene before calling raycast, shapeCast, or overlap.

Babylon Lite 1.27.0 reports collisions without body identities, so collision.other is null by default. Use trigger events for entity-aware reactions, or opt into the ADR-0013 waiver with physics({ collisionIdentities: "internal" }).

No, a body's entity must be a root entity because Havok writes the node's local pose directly. A parented body would be simulated in its parent's space and triggers error IGX-0907.