Three特效-扩散波

@TOC

概述

使用Three.js来创建智慧城市场景中的扩散波动画，主要原理是使用控制mesh的缩放，效果图：

贴图素材：

代码

1. 创建圆柱几何体 CylinderGeometry(radiusTop : Float, radiusBottom : Float, height : Float, radialSegments : Integer, heightSegments : Integer, openEnded : Boolean, thetaStart : Float, thetaLength : Float) radiusTop — 圆柱的顶部半径，默认值是1。 radiusBottom — 圆柱的底部半径，默认值是1。 height — 圆柱的高度，默认值是1。 radialSegments — 圆柱侧面周围的分段数，默认为8。 heightSegments — 圆柱侧面沿着其高度的分段数，默认值为1。 openEnded — 一个Boolean值，指明该圆锥的底面是开放的还是封顶的。默认值为false，即其底面默认是封顶的。 thetaStart — 第一个分段的起始角度，默认为0。（three o'clock position） thetaLength — 圆柱底面圆扇区的中心角，通常被称为“θ”（西塔）。默认值是2*Pi，这使其成为一个完整的圆柱。

let geometry = new THREE.CylinderGeometry(4, 4, 2, 64);

2. 创建多材质并生成mesh

let texture = new THREE.TextureLoader().load("zhu.png")
  texture.wrapS = texture.wrapT = THREE.RepeatWrapping; //每个都重复
  texture.repeat.set(1, 1)
  texture.needsUpdate = true

let materials = [
    new THREE.MeshBasicMaterial({
      map: texture,
      side: THREE.DoubleSide,
      transparent: true
    }),
    new THREE.MeshBasicMaterial({
      transparent: true,
      opacity: 0,
      side: THREE.DoubleSide
    }),
    new THREE.MeshBasicMaterial({
      transparent: true,
      opacity: 0,
      side: THREE.DoubleSide
    })
  ]
 
 let mesh = new THREE.Mesh(geometry, materials)

 scene.add(mesh)
  

完整代码

let texture = new THREE.TextureLoader().load("ball.png")
  texture.wrapS = texture.wrapT = THREE.RepeatWrapping; //每个都重复
  texture.repeat.set(1, 1)
  texture.needsUpdate = true


  let geometry = new THREE.CylinderGeometry(4, 4, 2, 64);
  let materials = [
    new THREE.MeshBasicMaterial({
      map: texture,
      side: THREE.DoubleSide,
      transparent: true
    }),
    new THREE.MeshBasicMaterial({
      transparent: true,
      opacity: 0,
      side: THREE.DoubleSide
    }),
    new THREE.MeshBasicMaterial({
      transparent: true,
      opacity: 0,
      side: THREE.DoubleSide
    })
  ]
  let mesh = new THREE.Mesh(geometry, materials)

  scene.add(mesh)

  let s = 0;
  let p = 1;
  function animate() {
	// 一定要在此函数中调用
    s += 0.01;
    p -= 0.005;
    if (s > 2) {
      s = 0;
      p = 1;
    }
    mesh.scale.set(1 + s, 1, 1 + s);
    mesh.material[0].opacity = p;
    
    requestAnimationFrame(animate)
  }

  animate()