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180 | 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()
const camera = new THREE.PerspectiveCamera(
75,
window.innerWidth / window.innerHeight,
0.1,
1000
)
camera.position.set(0, 0.75, 0.25)
const light = new THREE.DirectionalLight()
light.position.set(1, 1, 1)
scene.add(light)
const renderer = new THREE.WebGLRenderer()
renderer.setSize(window.innerWidth, window.innerHeight)
document.body.appendChild(renderer.domElement)
const controls = new OrbitControls(camera, renderer.domElement)
controls.enablePan = false
controls.enableDamping = true
const canvasD = document.getElementById('canvasD') as HTMLCanvasElement
const contextD = canvasD.getContext('2d') as CanvasRenderingContext2D
const canvasN = document.getElementById('canvasN') as HTMLCanvasElement
const contextN = canvasN.getContext('2d') as CanvasRenderingContext2D
contextN.fillStyle = '#7f7fff'
contextN.fillRect(0, 0, 128, 128)
const displacementMap = new THREE.CanvasTexture(canvasD)
const normalMap = new THREE.CanvasTexture(canvasN)
const geometry = new THREE.PlaneGeometry(1, 1, 128, 128)
const material = new THREE.MeshStandardMaterial({
displacementMap: displacementMap,
displacementScale: 0.1,
normalMap: normalMap,
})
const plane = new THREE.Mesh(geometry, material)
plane.rotation.x = -Math.PI / 2
scene.add(plane)
const raycaster = new THREE.Raycaster()
let intersects: THREE.Intersection[]
const mouse = new THREE.Vector2()
let ctrlDown = false
let ptrDown = false
// height2normal - based on www.mrdoob.com/lab/javascript/height2normal/
function height2normal(
context: CanvasRenderingContext2D,
contextN: CanvasRenderingContext2D
) {
var width = 128
var height = 128
var src = context.getImageData(0, 0, width, height)
var dst = contextN.createImageData(width, height)
for (var i = 0, l = width * height * 4; i < l; i += 4) {
var x1, x2, y1, y2
if (i % (width * 4) == 0) {
// left edge
x1 = src.data[i]
x2 = src.data[i + 4]
} else if (i % (width * 4) == (width - 1) * 4) {
// right edge
x1 = src.data[i - 4]
x2 = src.data[i]
} else {
x1 = src.data[i - 4]
x2 = src.data[i + 4]
}
if (i < width * 4) {
// top edge
y1 = src.data[i]
y2 = src.data[i + width * 4]
} else if (i > width * (height - 1) * 4) {
// bottom edge
y1 = src.data[i - width * 4]
y2 = src.data[i]
} else {
y1 = src.data[i - width * 4]
y2 = src.data[i + width * 4]
}
dst.data[i] = x1 - x2 + 127
dst.data[i + 1] = y1 - y2 + 127
dst.data[i + 2] = 255
dst.data[i + 3] = 255
}
contextN.putImageData(dst, 0, 0)
}
function draw(uv: THREE.Vector2) {
contextD.fillStyle = '#FFFFFF'
contextD.fillRect(uv.x * 128, 128 - uv.y * 128, 2, 2)
material.needsUpdate = true
;(material.displacementMap as THREE.Texture).needsUpdate = true
height2normal(contextD, contextN)
;(material.normalMap as THREE.Texture).needsUpdate = true
}
function raycast() {
raycaster.setFromCamera(mouse, camera)
intersects = raycaster.intersectObject(plane, false)
if (intersects.length > 0) {
draw(intersects[0].uv as THREE.Vector2)
}
}
document.addEventListener('mousemove', function (event) {
mouse.x = (event.clientX / window.innerWidth) * 2 - 1
mouse.y = -(event.clientY / window.innerHeight) * 2 + 1
if (ctrlDown && ptrDown) raycast()
})
renderer.domElement.addEventListener('pointerdown', function () {
ptrDown = true
if (ctrlDown) raycast()
})
renderer.domElement.addEventListener('pointerup', function () {
ptrDown = false
})
window.addEventListener('keydown', function (event) {
if (event.key === 'Control') {
renderer.domElement.style.cursor = 'crosshair'
controls.enabled = false
ctrlDown = true
}
})
window.addEventListener('keyup', function (event) {
if (event.key === 'Control') {
renderer.domElement.style.cursor = 'pointer'
controls.enabled = true
ctrlDown = false
}
})
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()
gui.add(material, 'displacementScale', 0, 0.2, 0.01)
function animate() {
requestAnimationFrame(animate)
controls.update()
render()
stats.update()
}
function render() {
renderer.render(scene, camera)
}
animate()
|