# RapierPhysics

Can be used to include Rapier as a Physics engine into `three.js` apps. The API can be initialized via:

The component automatically imports Rapier from a CDN so make sure to use the component with an active Internet connection.

## Code Example

    const physics = await RapierPhysics();

## Import

RapierPhysics is an addon, and must be imported explicitly, see Installation#Addons.

    import { RapierPhysics } from 'three/addons/physics/RapierPhysics.js';

## Methods

### .addHeightfield ( mesh : Mesh, width : number, depth : number, heights : Float32Array, scale : Object ) : RigidBody

Adds a heightfield terrain to the physics simulation.

mesh | The Three.js mesh representing the terrain.
width | The number of vertices along the width (x-axis) of the heightfield.
depth | The number of vertices along the depth (z-axis) of the heightfield.
heights | Array of height values for each vertex in the heightfield.

scale

Scale factors for the heightfield dimensions.

x | Scale factor for width.
y | Scale factor for height.
z | Scale factor for depth.

Returns: The created Rapier rigid body for the heightfield.

### .addMesh ( mesh : Mesh, mass : number, restitution : number )

Adds the given mesh to this physics simulation.

mesh | The mesh to add.
mass | The mass in kg of the mesh. Default is `0`.
restitution | The restitution of the mesh, usually from 0 to 1. Represents how "bouncy" objects are when they collide with each other. Default is `0`.

### .addScene ( scene : Object3D )

Adds the given scene to this physics simulation. Only meshes with a `physics` object in their Object3D#userData field will be honored. The object can be used to store the mass and restitution of the mesh. E.g.:

    box.userData.physics = { mass: 1, restitution: 0 };

scene | The scene or any type of 3D object to add.

### .removeMesh ( mesh : Mesh )

Removes the given mesh from this physics simulation.

mesh | The mesh to remove.

### .setMeshPosition ( mesh : Mesh, position : Vector3, index : number )

Set the position of the given mesh which is part of the physics simulation. Calling this method will reset the current simulated velocity of the mesh.

mesh | The mesh to update the position for.
position | The new position.
index | If the mesh is instanced, the index represents the instanced ID. Default is `0`.

### .setMeshVelocity ( mesh : Mesh, velocity : Vector3, index : number )

Set the velocity of the given mesh which is part of the physics simulation.

mesh | The mesh to update the velocity for.
velocity | The new velocity.
index | If the mesh is instanced, the index represents the instanced ID. Default is `0`.

## Source

examples/jsm/physics/RapierPhysics.js