@rzmps/jolt

Jolt Physics collision support for @rzmps/rzmps.

@rzmps/jolt allows particles using the @rzmps/rzmps Collision module to collide with bodies in an existing Jolt physics simulation.

It integrates with @barclah/jolt-physics, a WebAssembly/JavaScript binding for Jolt Physics. The package exposes an asynchronous initializer that returns the Jolt module used to construct the simulation.

Installation

npm install @rzmps/jolt @barclah/jolt-physics

@rzmps/rzmps, three, and @barclah/jolt-physics are peer dependencies.

Usage

Initialize Jolt and create your JoltInterface normally:

import initJolt from "@barclah/jolt-physics";
import { JoltCollisionBackend } from "@rzmps/jolt";
import { Collision } from "@rzmps/rzmps";

const Jolt = await initJolt();

// Configure JoltSettings...
const physicsInterface = new Jolt.JoltInterface(settings);

const collision = new Collision({
  backend: new JoltCollisionBackend({
    Jolt,
    interface: physicsInterface,
    objectLayer: 1,
  }),
});

The Jolt module must be the same initialized module instance used to create the supplied JoltInterface.

objectLayer determines which Jolt collision-layer rules are used when querying the world. It defaults to 1.

Custom query filters can also be supplied:

new JoltCollisionBackend({
  Jolt,
  interface: physicsInterface,
  broadPhaseLayerFilter,
  objectLayerFilter,
  bodyFilter,
  shapeFilter,
});

The backend does not initialize, step, or otherwise manage the Jolt simulation itself.

Particle impulses

Particles with a non-zero mass can transfer momentum to Jolt rigid bodies when they collide:

initialValues: {
  mass: 0.1,
}

Mass defaults to 0, so particles do not affect physics bodies unless explicitly enabled.

Cleanup

Jolt uses native WebAssembly allocations which are not garbage-collected automatically. Destroy the backend before destroying the associated JoltInterface:

backend.destroy();
Jolt.destroy(physicsInterface);

Any bodies created by the application should also be removed and destroyed through Jolt's BodyInterface before destroying the interface.