使用three.js 实现蜡烛效果

import * as THREE from "three"
import { OrbitControls } from "three/examples/jsm/controls/OrbitControls.js"var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(60, window.innerWidth / window.innerHeight, 1, 1000);
camera.position.set(3, 5, 8).setLength(15);
var renderer = new THREE.WebGLRenderer({ antialias: true });
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.setClearColor(0x101005);
renderer.shadowMap.enabled = true;
renderer.shadowMap.type = THREE.PCFSoftShadowMap;
document.body.appendChild(renderer.domElement);
window.addEventListener("resize", event => {camera.aspect = innerWidth / innerHeight;camera.updateProjectionMatrix()renderer.setSize(innerWidth, innerHeight);
})var controls = new OrbitControls(camera, renderer.domElement);
controls.enablePan = false;
controls.minPolarAngle = THREE.MathUtils.degToRad(60);
controls.maxPolarAngle = THREE.MathUtils.degToRad(95);
controls.minDistance = 4;
controls.maxDistance = 20;
controls.autoRotate = true;
controls.autoRotateSpeed = 1;
controls.target.set(0, 2, 0);
controls.update();var light = new THREE.DirectionalLight(0xffffff, 0.025);
light.position.setScalar(10);
scene.add(light);
scene.add(new THREE.AmbientLight(0xffffff, 0.0625));var casePath = new THREE.Path();
casePath.moveTo(0, 0);
casePath.lineTo(0, 0);
casePath.absarc(1.5, 0.5, 0.5, Math.PI * 1.5, Math.PI * 2);
casePath.lineTo(2, 1.5);
casePath.lineTo(1.99, 1.5);
casePath.lineTo(1.9, 0.5);
var caseGeo = new THREE.LatheGeometry(casePath.getPoints(), 64);
var caseMat = new THREE.MeshStandardMaterial({ color: "silver" });
var caseMesh = new THREE.Mesh(caseGeo, caseMat);
caseMesh.castShadow = true;var paraffinPath = new THREE.Path();
paraffinPath.moveTo(0, -.25);
paraffinPath.lineTo(0, -.25);
paraffinPath.absarc(1, 0, 0.25, Math.PI * 1.5, Math.PI * 2);
paraffinPath.lineTo(1.25, 0);
paraffinPath.absarc(1.89, 0.1, 0.1, Math.PI * 1.5, Math.PI * 2);
var paraffinGeo = new THREE.LatheGeometry(paraffinPath.getPoints(), 64);
paraffinGeo.translate(0, 1.25, 0);
var paraffinMat = new THREE.MeshStandardMaterial({ color: 0xffff99, side: THREE.BackSide, metalness: 0, roughness: 0.75 });
var paraffinMesh = new THREE.Mesh(paraffinGeo, paraffinMat);
caseMesh.add(paraffinMesh);var candlewickProfile = new THREE.Shape();
candlewickProfile.absarc(0, 0, 0.0625, 0, Math.PI * 2);var candlewickCurve = new THREE.CatmullRomCurve3([new THREE.Vector3(0, 0, 0),new THREE.Vector3(0, 0.5, -0.0625),new THREE.Vector3(0.25, 0.5, 0.125)
]);var candlewickGeo = new THREE.ExtrudeGeometry(candlewickProfile, {steps: 8,bevelEnabled: false,extrudePath: candlewickCurve
});var colors = [];
var color1 = new THREE.Color("black");
var color2 = new THREE.Color(0x994411);
var color3 = new THREE.Color(0xffff44);
for (let i = 0; i < candlewickGeo.attributes.position.count; i++) {if (candlewickGeo.attributes.position.getY(i) < 0.4) {color1.toArray(colors, i * 3);}else {color2.toArray(colors, i * 3);};if (candlewickGeo.attributes.position.getY(i) < 0.15) color3.toArray(colors, i * 3);
}
candlewickGeo.setAttribute('color', new THREE.BufferAttribute(new Float32Array(colors), 3));
candlewickGeo.translate(0, 0.95, 0);
var candlewickMat = new THREE.MeshBasicMaterial({ vertexColors: true });var candlewickMesh = new THREE.Mesh(candlewickGeo, candlewickMat);
caseMesh.add(candlewickMesh);// candle light
var candleLight = new THREE.PointLight(0xffaa33, 1, 5, 2);
candleLight.position.set(0, 3, 0);
candleLight.castShadow = true;
caseMesh.add(candleLight);
var candleLight2 = new THREE.PointLight(0xffaa33, 1, 10, 2);
candleLight2.position.set(0, 4, 0);
candleLight2.castShadow = true;
caseMesh.add(candleLight2);var flameMaterials = [];
function flame(isFrontSide) {let flameGeo = new THREE.SphereGeometry(0.5, 32, 32);flameGeo.translate(0, 0.5, 0);let flameMat = getFlameMaterial(true);flameMaterials.push(flameMat);let flame = new THREE.Mesh(flameGeo, flameMat);flame.position.set(0.06, 1.2, 0.06);flame.rotation.y = THREE.MathUtils.degToRad(-45);caseMesh.add(flame);
}flame(false);
flame(true);// table
var tableGeo = new THREE.CylinderGeometry(14, 14, 0.5, 64);
tableGeo.translate(0, -0.25, 0);
var tableMat = new THREE.MeshStandardMaterial({ map: new THREE.TextureLoader().load("https://threejs.org/examples/textures/hardwood2_diffuse.jpg"), metalness: 0, roughness: 0.75 });
var tableMesh = new THREE.Mesh(tableGeo, tableMat);
tableMesh.receiveShadow = true;tableMesh.add(caseMesh);
scene.add(tableMesh);var clock = new THREE.Clock();
var time = 0;render();
function render() {requestAnimationFrame(render);time += clock.getDelta();flameMaterials[0].uniforms.time.value = time;flameMaterials[1].uniforms.time.value = time;candleLight2.position.x = Math.sin(time * Math.PI) * 0.25;candleLight2.position.z = Math.cos(time * Math.PI * 0.75) * 0.25;candleLight2.intensity = 2 + Math.sin(time * Math.PI * 2) * Math.cos(time * Math.PI * 1.5) * 0.25;controls.update();renderer.render(scene, camera);
}function getFlameMaterial(isFrontSide) {let side = isFrontSide ? THREE.FrontSide : THREE.BackSide;return new THREE.ShaderMaterial({uniforms: {time: { value: 0 }},vertexShader: `uniform float time;varying vec2 vUv;varying float hValue;float random (in vec2 st) {return fract(sin(dot(st.xy,vec2(12.9898,78.233)))* 43758.5453123);}float noise (in vec2 st) {vec2 i = floor(st);vec2 f = fract(st);// Four corners in 2D of a tilefloat a = random(i);float b = random(i + vec2(1.0, 0.0));float c = random(i + vec2(0.0, 1.0));float d = random(i + vec2(1.0, 1.0));// Smooth Interpolation// Cubic Hermine Curve.  Same as SmoothStep()vec2 u = f*f*(3.0-2.0*f);// u = smoothstep(0.,1.,f);// Mix 4 coorners percentagesreturn mix(a, b, u.x) +(c - a)* u.y * (1.0 - u.x) +(d - b) * u.x * u.y;}void main() {vUv = uv;vec3 pos = position;pos *= vec3(0.8, 2, 0.725);hValue = position.y;//float sinT = sin(time * 2.) * 0.5 + 0.5;float posXZlen = length(position.xz);pos.y *= 1. + (cos((posXZlen + 0.25) * 3.1415926) * 0.25 + noise(vec2(0, time)) * 0.125 + noise(vec2(position.x + time, position.z + time)) * 0.5) * position.y; // flame heightpos.x += noise(vec2(time * 2., (position.y - time) * 4.0)) * hValue * 0.0312; // flame tremblingpos.z += noise(vec2((position.y - time) * 4.0, time * 2.)) * hValue * 0.0312; // flame tremblinggl_Position = projectionMatrix * modelViewMatrix * vec4(pos,1.0);}`,fragmentShader: `varying float hValue;varying vec2 vUv;// honestly stolen from https://www.shadertoy.com/view/4dsSzrvec3 heatmapGradient(float t) {return clamp((pow(t, 1.5) * 0.8 + 0.2) * vec3(smoothstep(0.0, 0.35, t) + t * 0.5, smoothstep(0.5, 1.0, t), max(1.0 - t * 1.7, t * 7.0 - 6.0)), 0.0, 1.0);}void main() {float v = abs(smoothstep(0.0, 0.4, hValue) - 1.);float alpha = (1. - v) * 0.99; // bottom transparencyalpha -= 1. - smoothstep(1.0, 0.97, hValue); // tip transparencygl_FragColor = vec4(heatmapGradient(smoothstep(0.0, 0.3, hValue)) * vec3(0.95,0.95,0.4), alpha) ;gl_FragColor.rgb = mix(vec3(0,0,1), gl_FragColor.rgb, smoothstep(0.0, 0.3, hValue)); // blueish for bottomgl_FragColor.rgb += vec3(1, 0.9, 0.5) * (1.25 - vUv.y); // make the midst brightergl_FragColor.rgb = mix(gl_FragColor.rgb, vec3(0.66, 0.32, 0.03), smoothstep(0.95, 1., hValue)); // tip}`,transparent: true,side: side})}/*** 名称: 蜡烛* 作者: 优雅永不过时 https://github.com/z2586300277
*/