Object3D

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This course was updated in 2024. For the newer content, please visit Object3D

Video Lecture

Description

Object3D is the base class for many objects in Three.js provides methods and properties for manipulating objects in 3D space.

Most common examples are Meshes, Lights, Cameras and Groups of Object3Ds.

The full list of methods and properties can be found in the Three.js documentation at THREE.Object3D

In this video I will demonstrate the most common things you will do with an Object3D and that is change,

• Rotation
• Position
• Scale
• Visibility

A list of Three.js objects that derive from the Object3D base class are,

• Scene
• Mesh
  • InstancedMesh
  • SkinnedMesh
• Camera
  • OrthographicCamera
  • PerspectiveCamera
• CubeCamera
• Group
• Sprite
• LOD
• Bone
• Line
  • LineLoop
  • LineSegments
• Points
• Light
  • AmbientLight
  • DirectionalLight
  • HemisphereLight
  • PointLight
  • RectAreaLight
  • SpotLight
• AudioListener
• Audio
  • PositionalAudio
• SpotLightHelper
• HemisphereLightHelper
• DirectionalLightHelper
• ArrowHelper

Some of the above classes are also derived from parent classes that derive from the Object3D.

Final Script

./src/client/client.ts

import * as THREE from 'three'
import { OrbitControls } from 'three/examples/jsm/controls/OrbitControls'
import Stats from 'three/examples/jsm/libs/stats.module'
import { GUI } from 'dat.gui'

const scene = new THREE.Scene()
scene.add(new THREE.AxesHelper(5))

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)

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()
}

const stats = new Stats()
document.body.appendChild(stats.dom)

const gui = new GUI()
const cubeFolder = gui.addFolder('Cube')
const cubeRotationFolder = cubeFolder.addFolder('Rotation')
cubeRotationFolder.add(cube.rotation, 'x', 0, Math.PI * 2)
cubeRotationFolder.add(cube.rotation, 'y', 0, Math.PI * 2)
cubeRotationFolder.add(cube.rotation, 'z', 0, Math.PI * 2)
cubeFolder.open()
cubeRotationFolder.open()
const cubePositionFolder = cubeFolder.addFolder('Position')
cubePositionFolder.add(cube.position, 'x', -10, 10, 2)
cubePositionFolder.add(cube.position, 'y', -10, 10, 2)
cubePositionFolder.add(cube.position, 'z', -10, 10, 2)
cubeFolder.open()
cubePositionFolder.open()
const cubeScaleFolder = cubeFolder.addFolder('Scale')
cubeScaleFolder.add(cube.scale, 'x', -5, 5)
cubeScaleFolder.add(cube.scale, 'y', -5, 5)
cubeScaleFolder.add(cube.scale, 'z', -5, 5)
cubeFolder.add(cube, 'visible')
cubeFolder.open()
cubeScaleFolder.open()

function animate() {
  requestAnimationFrame(animate)

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

  render()

  stats.update()
}

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

animate()
//render()

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