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NormalMap

Video Lecture

Normalmap Normalmap Normalmap

Description

Even more impressive than the bumpmap is the normalMap.

The normalMap uses the rgb values of the image to affect the the lighting.

It also simulates perceived depth in relation to the lights but uses a different algorithm to indicate how much to alter the lighting in the up/down and left/right directions.

Use the normalScale property to alter the perceived depth. The normalScale requires a THREE.Vector2. Typically the x,y values of the normalScale would be between 0 and 1.0. I have values as high as 10 in my example to make it more extreme.

Below is the image used as the normal map.

Earth Normalmap

Resources

The image files used in this lesson can be downloaded from the file named material-textures-3.zip. Extract the material-textures-3.zip contents into the ./dist/client/img/ folder.

material-textures-3.zip

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 'three/examples/jsm/libs/dat.gui.module'

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

const light = new THREE.PointLight(0xffffff, 2)
light.position.set(0, 2, 5)
scene.add(light)

const camera = new THREE.PerspectiveCamera(
    75,
    window.innerWidth / window.innerHeight,
    0.1,
    1000
)
camera.position.z = 1

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

const controls = new OrbitControls(camera, renderer.domElement)
controls.enableDamping = true

const planeGeometry = new THREE.PlaneGeometry(3.6, 1.8)

const material = new THREE.MeshPhongMaterial()

const texture = new THREE.TextureLoader().load('img/worldColour.5400x2700.jpg')
material.map = texture

const normalTexture = new THREE.TextureLoader().load(
    'img/earth_normalmap_8192x4096.jpg'
)
material.normalMap = normalTexture
material.normalScale.set(2, 2)

const plane = new THREE.Mesh(planeGeometry, material)
scene.add(plane)

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

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

const gui = new GUI()
gui.add(material.normalScale, 'x', 0, 10, 0.01)
gui.add(material.normalScale, 'y', 0, 10, 0.01)
gui.add(light.position, 'x', -20, 20).name('Light Pos X')

function animate() {
    requestAnimationFrame(animate)

    controls.update()

    render()

    stats.update()
}

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

animate()