打造Github首页的动态飞线效果

一、导语

Github首页的地球动态飞线，大家都比较熟悉吧

二、分析

由大量随机的3点构造出贝塞尔曲线，然后开始从起点到终点的飞行后，然后再从起点到终点的消失，就此完成整个过程

三、基础代码

createCurve(startPoint, endPoint) {
    // 创建一个贝塞尔曲线
    startPoint = new THREE.Vector3(startPoint.x, 4, startPoint.z)
    const endPoints = new THREE.Vector3(endPoint.x, 4, endPoint.z)
    const center = new THREE.Vector3()
    center.lerpVectors(startPoint, endPoints, 0.5)
    console.log('center: ', center)
    center.y += 3.0
    const curve = new THREE.QuadraticBezierCurve3(startPoint, center, endPoints)
    // 获取数组点
    this.points = curve.getPoints(100)
    this.curveGeometry = new LineGeometry()
    // 设置起始点
    this.curveGeometry.setPositions([startPoint.x, startPoint.y, this.startPoint.z])
    this.lineMaterial = new LineMaterial({
      color: new THREE.Color('#993399'),
      linewidth: 2,
      dashed: false
    })
    this.lineMaterial.resolution.set(window.innerWidth, window.innerHeight)
    this.curveObject = new Line2(this.curveGeometry, this.lineMaterial)
    this.scene.add(this.curveObject)
  }