cannon.js
Lightweight 3D physics for the web
Inspired by three.js and ammo.js, and driven by the fact that the web lacks a physics engine, here comes cannon.js.
The rigid body physics engine includes simple collision detection, various body shapes, contacts, friction and constraints.
Demos - Documentation - Rendering hints - NPM package - CDN
Browser install
Just include cannon.js or cannon.min.js in your html and you're done:
<script src="cannon.min.js"></script>
Node.js install
Install the cannon package via NPM:
npm install --save cannon
Alternatively, point to the Github repo directly to get the very latest version:
npm install --save schteppe/cannon.js
Example
The sample code below creates a sphere on a plane, steps the simulation, and prints the sphere simulation to the console. Note that Cannon.js uses SI units (metre, kilogram, second, etc.).
// Setup our world
var world = new CANNON.World();
world.gravity.set(0, 0, -9.82); // m/s²
// Create a sphere
var radius = 1; // m
var sphereBody = new CANNON.Body({
mass: 5, // kg
position: new CANNON.Vec3(0, 0, 10), // m
shape: new CANNON.Sphere(radius)
});
world.addBody(sphereBody);
// Create a plane
var groundBody = new CANNON.Body({
mass: 0 // mass == 0 makes the body static
});
var groundShape = new CANNON.Plane();
groundBody.addShape(groundShape);
world.addBody(groundBody);
var fixedTimeStep = 1.0 / 60.0; // seconds
var maxSubSteps = 3;
// Start the simulation loop
var lastTime;
(function simloop(time){
requestAnimationFrame(simloop);
if(lastTime !== undefined){
var dt = (time - lastTime) / 1000;
world.step(fixedTimeStep, dt, maxSubSteps);
}
console.log("Sphere z position: " + sphereBody.position.z);
lastTime = time;
})();
If you want to know how to use cannon.js with a rendering engine, for example Three.js, see the Examples.
Features
- Rigid body dynamics
- Discrete collision detection
- Contacts, friction and restitution
- Constraints
- PointToPoint (a.k.a. ball/socket joint)
- Distance
- Hinge (with optional motor)
- Lock
- ConeTwist
- Gauss-Seidel constraint solver and an island split algorithm
- Collision filters
- Body sleeping
- Experimental SPH / fluid support
- Various shapes and collision algorithms (see table below), Sphere, Plane, Box, Convex, Particle, Heightfield, Trimesh, :-----------, :------:, :-----:, :---:, :------:, :--------:, :-----------:, :-------:, Sphere, Yes, Yes, Yes, Yes, Yes, Yes, Yes, Plane, -, -, Yes, Yes, Yes, -, Yes, Box, -, -, Yes, Yes, Yes, Yes, (todo), Cylinder, -, -, Yes, Yes, Yes, Yes, (todo), Convex, -, -, -, Yes, Yes, Yes, (todo), Particle, -, -, -, -, -, (todo), (todo), Heightfield, -, -, -, -, -, -, (todo), Trimesh, -, -, -, -, -, -, -, ### Todo
The simpler todos are marked with@todoin the code. Github Issues can and should also be used for todos.
Help
Create an issue if you need help.