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Animation Loop

Tip

This course was updated in 2024. For the newer content, please visit Animation Loop

Video Lecture

Animation Loop

Description

The window.requestAnimationFrame() method tells the browser that you wish to perform an animation and requests that the browser calls a specified function to update an animation before the next repaint. The method takes a callback as an argument to be invoked before the repaint.

Note

The callback routine must itself call requestAnimationFrame() if you want to animate another frame at the next repaint.

The number of callbacks is usually 60 times per second, but will generally match the display refresh rate in most web browsers as per W3C recommendation. requestAnimationFrame() calls are paused in most browsers when running in background tabs or hidden <iframe>s in order to improve performance and battery life.

Start Scripts

Lets put the scripts back to the way the where before the previous lesson.

./dist/client/index.html

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<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <title>Three.js TypeScript Tutorials by Sean Bradley : https://sbcode.net/threejs</title>
    <style>
      body {
        overflow: hidden;
        margin: 0px;
      }
    </style>
  </head>

  <body>
    <script type="module" src="bundle.js"></script>
  </body>
</html>

./src/client/client.ts

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import * as THREE from 'three'
import { OrbitControls } from 'three/examples/jsm/controls/OrbitControls'

const scene = new THREE.Scene()

const camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000)
camera.position.z = 2

const renderer = new THREE.WebGLRenderer()
renderer.setSize(window.innerWidth, window.innerHeight)
document.body.appendChild(renderer.domElement)

new OrbitControls(camera, renderer.domElement)

const geometry = new THREE.BoxGeometry()
const material = new THREE.MeshBasicMaterial({
  color: 0x00ff00,
  wireframe: true,
})

const cube = new THREE.Mesh(geometry, material)
scene.add(cube)

window.addEventListener('resize', onWindowResize, false)
function onWindowResize() {
  camera.aspect = window.innerWidth / window.innerHeight
  camera.updateProjectionMatrix()
  renderer.setSize(window.innerWidth, window.innerHeight)
  render()
}

function animate() {
  requestAnimationFrame(animate)

  cube.rotation.x += 0.01
  cube.rotation.y += 0.01

  render()
}

function render() {
  renderer.render(scene, camera)
}

animate()

Final Script

The final client.ts script at the end of the video

./src/client/client.ts

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import * as THREE from 'three'
import { OrbitControls } from 'three/examples/jsm/controls/OrbitControls'

const scene = new THREE.Scene()

const camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000)
camera.position.z = 2

const renderer = new THREE.WebGLRenderer()
renderer.setSize(window.innerWidth, window.innerHeight)
document.body.appendChild(renderer.domElement)

const controls = new OrbitControls(camera, renderer.domElement)
controls.addEventListener('change', render) //this line is unnecessary if you are re-rendering within the animation loop

const geometry = new THREE.BoxGeometry()
const material = new THREE.MeshBasicMaterial({
  color: 0x00ff00,
  wireframe: true,
})

const cube = new THREE.Mesh(geometry, material)
scene.add(cube)

window.addEventListener('resize', onWindowResize, false)
function onWindowResize() {
  camera.aspect = window.innerWidth / window.innerHeight
  camera.updateProjectionMatrix()
  renderer.setSize(window.innerWidth, window.innerHeight)
  render()
}

// function animate() {
//     requestAnimationFrame(animate)

//     cube.rotation.x += 0.01
//     cube.rotation.y += 0.01

//     render()
// }

function render() {
  renderer.render(scene, camera)
}

//animate()
render()

MDN Window.requestAnimationFrame()

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