Getting started

Installing Rapier from NPM#

Rapier is available as the @dimforge/rapier2d and @dimforge/rapier3d NPM packages. You may add the following to your package.json:

"dependencies": {
"@dimforge/rapier2d": "*", // Replace the * by the latest version number.
}

Because Rapier is actually a WebAssembly module, it has to be loaded asynchronously. The following shows a basic example with a dynamic rigid-body falling on the ground.

import('@dimforge/rapier2d').then(RAPIER => {
// Use the RAPIER module here.
let gravity = { x: 0.0, y: -9.81 };
let world = new RAPIER.World(gravity);
// Create the ground
let groundColliderDesc = RAPIER.ColliderDesc.cuboid(10.0, 0.1);
world.createCollider(groundColliderDesc);
// Create a dynamic rigid-body.
let rigidBodyDesc = RAPIER.RigidBodyDesc.newDynamic()
.setTranslation(0.0, 1.0);
let rigidBody = world.createRigidBody(rigidBodyDesc);
// Create a cuboid collider attached to the dynamic rigidBody.
let colliderDesc = RAPIER.ColliderDesc.cuboid(0.5, 0.5);
let collider = world.createCollider(colliderDesc, rigidBody.handle);
// Game loop. Replace by your own game loop system.
let gameLoop = () => {
// Ste the simulation forward.
world.step();
// Get and print the rigid-body's position.
let position = rigidBody.translation();
console.log("Rigid-body position: ", position.x, position.y);
setTimeout(gameLoop, 16);
};
gameLoop();
})

See the testbed3d/src/demos and testbed2d/src/demos folders for examples on how to initialize a Rapier physics world using these bindings.

Using Rapier without a bundler#

If you are attempting to use Rapier without a bundler, or if you are using a bundler that doesn't support WASM files properly, the previous solution will be difficult to get working. The alternative is to use our compatibility UMD packages @dimforge/rapier2d-compat or @dimforge/rapier3d-compat. These packages embed the WASM file (encoded in base64) into the main JS file. This results in a slightly different initialization process:

import RAPIER from 'https://cdn.skypack.dev/@dimforge/rapier2d-compat';
RAPIER.init().then(() => {
// Run the simulation.
});
// OR using the await syntax:
async function run_simulation() {
await RAPIER.init();
// Run the simulation.
}

A complete example can be found on codepen.