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Directional Light Shadow

Video Lecture

Directional Light Shadow

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Description

Note

Since Three r155, the default of WebGLRenderer.useLegacyLights was changed from true to false and will also be deprecated in r165. This means that intensity may need to be changed when using various types of lights if you want them to match your previous versions of Threejs. In simplest terms, the intensities for ambient, hemisphere, directional, spot lights and light maps can be restored by multiplying PI with the existing light intensity values.

E.g., if your intensity was 2, use

new THREE.DirectionalLight(0xffffff, Math.PI * 2)

The Directional Light Shadow uses an OrthographicCamera to calculate the shadows, rather than a PerspectiveCamera. This is because the light rays from the DirectionalLight are parallel.

The OrthographicCamera default frustum dimensions are

Direction Value
left -5
bottom -5
right 5
top 5
near 0.5
far 500
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Lesson Script

./src/client/client.ts

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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 light = new THREE.DirectionalLight(0xffffff, Math.PI)
light.castShadow = true
light.shadow.mapSize.width = 512
light.shadow.mapSize.height = 512
light.shadow.camera.near = 0.5
light.shadow.camera.far = 100
scene.add(light)

//const helper = new THREE.DirectionalLightHelper(light);
const helper = new THREE.CameraHelper(light.shadow.camera)
scene.add(helper)

const camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000)
camera.position.z = 7

const renderer = new THREE.WebGLRenderer()
renderer.setSize(window.innerWidth, window.innerHeight)
renderer.shadowMap.enabled = true
renderer.shadowMap.type = THREE.PCFSoftShadowMap
//renderer.shadowMap.type = THREE.BasicShadowMap
//renderer.shadowMap.type = THREE.PCFShadowMap
//renderer.shadowMap.type = THREE.VSMShadowMap
document.body.appendChild(renderer.domElement)

new OrbitControls(camera, renderer.domElement)

const planeGeometry = new THREE.PlaneGeometry(100, 20)
const plane = new THREE.Mesh(planeGeometry, new THREE.MeshPhongMaterial())
plane.rotateX(-Math.PI / 2)
plane.position.y = -1.75
plane.receiveShadow = true
scene.add(plane)

const torusGeometry = [new THREE.TorusGeometry(), new THREE.TorusGeometry(), new THREE.TorusGeometry(), new THREE.TorusGeometry(), new THREE.TorusGeometry()]

const material = [new THREE.MeshBasicMaterial(), new THREE.MeshLambertMaterial(), new THREE.MeshPhongMaterial(), new THREE.MeshPhysicalMaterial({}), new THREE.MeshToonMaterial()]

const torus = [
  new THREE.Mesh(torusGeometry[0], material[0]),
  new THREE.Mesh(torusGeometry[1], material[1]),
  new THREE.Mesh(torusGeometry[2], material[2]),
  new THREE.Mesh(torusGeometry[3], material[3]),
  new THREE.Mesh(torusGeometry[4], material[4]),
]

const texture = new THREE.TextureLoader().load('img/grid.png')
material[0].map = texture
material[1].map = texture
material[2].map = texture
material[3].map = texture
material[4].map = texture

torus[0].position.x = -8
torus[1].position.x = -4
torus[2].position.x = 0
torus[3].position.x = 4
torus[4].position.x = 8

torus[0].castShadow = true
torus[1].castShadow = true
torus[2].castShadow = true
torus[3].castShadow = true
torus[4].castShadow = true

torus[0].receiveShadow = true
torus[1].receiveShadow = true
torus[2].receiveShadow = true
torus[3].receiveShadow = true
torus[4].receiveShadow = true

scene.add(torus[0])
scene.add(torus[1])
scene.add(torus[2])
scene.add(torus[3])
scene.add(torus[4])

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 data = {
  color: light.color.getHex(),
  mapsEnabled: true,
  shadowMapSizeWidth: 512,
  shadowMapSizeHeight: 512,
}

const gui = new GUI()
const lightFolder = gui.addFolder('THREE.Light')
lightFolder.addColor(data, 'color').onChange(() => {
  light.color.setHex(Number(data.color.toString().replace('#', '0x')))
})
lightFolder.add(light, 'intensity', 0, Math.PI * 2, 0.01)

const directionalLightFolder = gui.addFolder('THREE.DirectionalLight')
directionalLightFolder.add(light.shadow.camera, 'left', -10, -1, 0.1).onChange(() => light.shadow.camera.updateProjectionMatrix())
directionalLightFolder.add(light.shadow.camera, 'right', 1, 10, 0.1).onChange(() => light.shadow.camera.updateProjectionMatrix())
directionalLightFolder.add(light.shadow.camera, 'top', 1, 10, 0.1).onChange(() => light.shadow.camera.updateProjectionMatrix())
directionalLightFolder.add(light.shadow.camera, 'bottom', -10, -1, 0.1).onChange(() => light.shadow.camera.updateProjectionMatrix())
directionalLightFolder.add(light.shadow.camera, 'near', 0.1, 100).onChange(() => light.shadow.camera.updateProjectionMatrix())
directionalLightFolder.add(light.shadow.camera, 'far', 0.1, 100).onChange(() => light.shadow.camera.updateProjectionMatrix())
directionalLightFolder.add(data, 'shadowMapSizeWidth', [256, 512, 1024, 2048, 4096]).onChange(() => updateShadowMapSize())
directionalLightFolder.add(data, 'shadowMapSizeHeight', [256, 512, 1024, 2048, 4096]).onChange(() => updateShadowMapSize())
directionalLightFolder.add(light.position, 'x', -50, 50, 0.01)
directionalLightFolder.add(light.position, 'y', -50, 50, 0.01)
directionalLightFolder.add(light.position, 'z', -50, 50, 0.01)
directionalLightFolder.open()

function updateShadowMapSize() {
  light.shadow.mapSize.width = data.shadowMapSizeWidth
  light.shadow.mapSize.height = data.shadowMapSizeHeight
  ;(light.shadow.map as any) = null
}

const meshesFolder = gui.addFolder('Meshes')
meshesFolder.add(data, 'mapsEnabled').onChange(() => {
  material.forEach((m) => {
    if (data.mapsEnabled) {
      m.map = texture
    } else {
      m.map = null
    }
    m.needsUpdate = true
  })
})

function animate() {
  requestAnimationFrame(animate)

  helper.update()

  torus.forEach((t) => {
    t.rotation.y += 0.01
  })

  render()

  stats.update()
}

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

animate()