时间轴动画 · Gsap TimeLine · ▶ 在线运行案例

时间轴动画

你将学到什么

  • OrbitControls 相机轨道交互
  • GSAP 时间轴与补间动画
  • requestAnimationFrame 渲染循环与 resize 自适应

效果说明

本案例演示 时间轴动画 效果：基于 WebGL 实现「时间轴动画」可视化效果，附完整可运行源码；核心用到 OrbitControls、GSAP。建议先打开文首在线案例查看动态画面，再对照下方源码逐步理解。

核心概念

  • Scene / Camera / WebGLRenderer 构成最小渲染闭环；大场景可开 logarithmicDepthBuffer 缓解 Z-fighting。
  • OrbitControls 提供轨道旋转/缩放；开启 enableDamping 后需在 animate 中 controls.update()。
  • 阅读下方完整源码时，建议从 init / load / animate 三条主线入手，再深入 shader 与工具函数。

实现步骤

  1. 搭建 Scene、PerspectiveCamera、WebGLRenderer，挂载 canvas 并处理 resize
  2. 创建 OrbitControls（及 Raycaster 等交互控件，若源码包含）
  3. 在定时器或 GSAP 时间轴中更新 uniform / 变换，驱动特效播放
  4. 在 requestAnimationFrame 循环中更新状态并 render（Cesium 为 viewer.render 或自动渲染）

代码要点

import * as THREE from 'three'
import { OrbitControls } from 'three/examples/jsm/controls/OrbitControls.js'
import gsap from 'gsap'

const box = document.getElementById('box')
const scene = new THREE.Scene()
const camera = new THREE.PerspectiveCamera(75, box.clientWidth / box.clientHeight, 0.1, 100000)
camera.position.set(0, 10, 20)

const renderer = new THREE.WebGLRenderer({ antialias: true, alpha: true })
renderer.setSize(box.clientWidth, box.clientHeight)
renderer.shadowMap.enabled = true
box.appendChild(renderer.domElement)

new OrbitControls(camera, renderer.domElement)

// 场景设置
scene.background = new THREE.Color(0x87ceeb)
scene.add(new THREE.AmbientLight(0xffffff, 0.6))
const light = new THREE.DirectionalLight(0xffffff, 2)
light.position.set(10, 20, 5)
light.castShadow = true
scene.add(light)

const ground = new THREE.Mesh( new THREE.PlaneGeometry(30, 30),new THREE.MeshLambertMaterial({ color: 0x228b22 }))
ground.rotation.x = -Math.PI / 2
ground.receiveShadow = true
scene.add(ground)

// 花朵
const flower = new THREE.Group()
const stem = new THREE.Mesh(
    new THREE.CylinderGeometry(0.1, 0.1, 3),
    new THREE.MeshPhongMaterial({ color: 0x228b22 })
)
stem.position.y = 1.5
stem.castShadow = true

const petals = new THREE.Mesh(
    new THREE.SphereGeometry(1.2, 12, 12),
    new THREE.MeshPhongMaterial({ color: 0xff69b4, shininess: 100 })
)
petals.position.y = 3
petals.scale.set(1, 0.5, 1)
petals.castShadow = true

flower.add(stem, petals)
scene.add(flower)

// 蝴蝶
const butterfly = new THREE.Group()
const body = new THREE.Mesh(
    new THREE.CylinderGeometry(0.05, 0.05, 1),
    new THREE.MeshPhongMaterial({ color: 0x8b4513 })
)
const wing1 = new THREE.Mesh(
    new THREE.SphereGeometry(0.4, 8, 8),
    new THREE.MeshPhongMaterial({ color: 0xff6347, transparent: true, opacity: 0.8 })
)
wing1.scale.set(1.5, 0.1, 1)
wing1.position.set(0.3, 0, 0)

const wing2 = wing1.clone()
wing2.position.set(-0.3, 0, 0)

butterfly.add(body, wing1, wing2)
butterfly.position.set(5, 4, 0)
scene.add(butterfly)

// 简洁花园动画
const tl = gsap.timeline({ repeat: -1, yoyo: true }) // repeat: -1 无限循环, yoyo: true 往返动画

tl.from(flower.scale, { x: 0, y: 0, z: 0, duration: 2, ease: "back.out(1.7)" })
  .to(petals.material.color, { r: 1, g: 0.8, b: 0.2, duration: 1 }, "-=0.5") // -=0.5 表示与前一个动画同时开始
  .to(butterfly.position, { x: 0, y: 5, z: 2, duration: 3, ease: "power1.inOut" })
  .to(butterfly.rotation, { z: Math.PI / 4, duration: 0.5 }, "-=1") // -=1 表示与前一个动画同时开始
  .to(petals.scale, { x: 1.3, y: 0.6, z: 1.3, duration: 1 })
  .to(butterfly.position, { x: -3, y: 3, z: -2, duration: 2 })

animate()

function animate() {
    requestAnimationFrame(animate)
    
    // 蝴蝶翅膀扇动
    wing1.rotation.z = Math.sin(Date.now() * 0.02) * 0.3
    wing2.rotation.z = -Math.sin(Date.now() * 0.02) * 0.3
    
    // 花朵轻微摆动
    petals.rotation.y += 0.005
    
    renderer.render(scene, camera)
}

window.onresize = () => {
    renderer.setSize(box.clientWidth, box.clientHeight)
    camera.aspect = box.clientWidth / box.clientHeight
    camera.updateProjectionMatrix()
}

完整源码：GitHub

小结