cannon-es-control
Version:
A lightweight 3D physics engine written in JavaScript with control system tools
153 lines (124 loc) • 5 kB
HTML
<html lang="en">
<head>
<meta charset="utf-8" />
<title>cannon.js - sleep demo</title>
<link rel="stylesheet" href="css/style.css" type="text/css" />
<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0" />
</head>
<body>
<script type="module">
import * as CANNON from '../dist/cannon-es-control.js'
import { Demo } from './js/Demo.js'
/**
* When a body sleeps, it does not move until it gets touched by another body.
* Why is this handy? Well, it can help you get a more stable simulation, and increase performance. No collision detection is made between sleeping bodies (and static ones).
*/
const demo = new Demo()
// Sleep demo
demo.addScene('Sleep', () => {
const world = setupWorld(demo)
// Create sphere
const size = 1
const sphere = new CANNON.Sphere(size)
const sphereBody = new CANNON.Body({ mass: 1 })
sphereBody.addShape(sphere)
sphereBody.position.set(0, size * 6, 0)
world.addBody(sphereBody)
demo.addVisual(sphereBody)
// Allow sleeping
world.allowSleep = true
sphereBody.allowSleep = true
// Sleep parameters
sphereBody.sleepSpeedLimit = 0.1 // Body will feel sleepy if speed<1 (speed == norm of velocity)
sphereBody.sleepTimeLimit = 1 // Body falls asleep after 1s of sleepiness
sphereBody.addEventListener('sleepy', (event) => {
console.log('The sphere is feeling sleepy...')
})
sphereBody.addEventListener('sleep', (event) => {
console.log('The sphere fell asleep!')
})
})
// Wake up demo
demo.addScene('Wake up when hit', () => {
const world = setupWorld(demo)
// Create sphere
const size = 2
const sphere = new CANNON.Sphere(size)
const sphereBody1 = new CANNON.Body({ mass: 1 })
sphereBody1.addShape(sphere)
sphereBody1.position.set(0, size, 0)
world.addBody(sphereBody1)
demo.addVisual(sphereBody1)
// Force it to sleep
sphereBody1.sleep()
// Create sphere that will wake up the first one
const sphereBody2 = new CANNON.Body({ mass: 1 })
sphereBody2.addShape(sphere)
sphereBody2.position.set(-size * 10, size, 0)
sphereBody2.velocity.set(10, 0, 0)
sphereBody2.angularDamping = 0.0
sphereBody2.linearDamping = 0.0
world.addBody(sphereBody2)
demo.addVisual(sphereBody2)
// Allow sleeping
world.allowSleep = true
sphereBody1.allowSleep = true
sphereBody2.allowSleep = true
// Sleep parameters
sphereBody1.sleepSpeedLimit = 0.5
sphereBody1.sleepTimeLimit = 1
// The body wakes up when it gets a new contact
sphereBody1.addEventListener('wakeup', (event) => {
console.log('The sphere woke up!')
})
})
// Wake up demo
demo.addScene('Wake up with impulse', () => {
const world = setupWorld(demo)
// Create sphere
const size = 2
const sphere = new CANNON.Sphere(size)
const sphereBody = new CANNON.Body({ mass: 1 })
sphereBody.addShape(sphere)
sphereBody.position.set(0, size, 0)
world.addBody(sphereBody)
demo.addVisual(sphereBody)
// Force it to sleep
sphereBody.sleep()
// Allow sleeping
world.allowSleep = true
sphereBody.allowSleep = true
// Sleep parameters
sphereBody.sleepSpeedLimit = 0.5
sphereBody.sleepTimeLimit = 1
// Apply an impulse after a bit
setTimeout(() => {
sphereBody.applyLocalImpulse(new CANNON.Vec3(5, 0, 0), new CANNON.Vec3())
}, 1000)
// The body wakes up when it gets a new contact
sphereBody.addEventListener('wakeup', (event) => {
console.log('The sphere woke up!')
})
})
demo.start()
function setupWorld(demo) {
const world = demo.getWorld()
world.gravity.set(0, -10, 0)
// Tweak contact properties.
// Contact stiffness - use to make softer/harder contacts
world.defaultContactMaterial.contactEquationStiffness = 1e7
// Stabilization time in number of timesteps
world.defaultContactMaterial.contactEquationRelaxation = 5
// Static ground plane
const groundShape = new CANNON.Plane()
const groundBody = new CANNON.Body({ mass: 0 })
groundBody.addShape(groundShape)
groundBody.quaternion.setFromEuler(-Math.PI / 2, 0, 0)
world.addBody(groundBody)
demo.addVisual(groundBody)
return world
}
</script>
</body>
</html>