烟花

var SimpleParticle = function()

{

this.particles = [];

this.explode = function (x, y, idx) {

  if (!this.particles[idx]) {

      var colors = [0x00B6F1, 0x1800FF, 0xFF0000, 0xFEFF00, 0x00FF00, 0xf25346, 0xd8d0d1, 0x59332e, 0x23190f, 0xF5986E, 0xf4ce93, 0x68c3c0];

      this.materials = [];

      var geometry = new THREE.PlaneGeometry(0.2, 0.2);

      for (var i = 0; i < colors.length; ++i) {

          this.materials.push(new THREE.MeshBasicMaterial({ color: colors[i], transparent: true }));

      }

      this.particles[idx] = [];

      for (var i = 0; i < 64; ++i) {

          var particle = new THREE.Mesh(geometry, this.materials[i % colors.length]);

          particle.position.set(0, 0, -9.9);

          camera.add(particle);

          this.particles[idx].push(particle);

      }

  }

  var t1 = 1000;

  var t2 = 1000;

  for (var i = 0; i < this.particles[idx].length; ++i) {

      var x0 = x,

          y0 = y;

      this.particles[idx][i].position.set(x0, y0, -9.9);

      this.particles[idx][i].rotation.z =  Math.random() * Math.PI/2;

      // 快速 随机左右散开，占 2/3

      var x1 = (1 - 2 * Math.random()) * 5 + x0;

      var y1 = (1 - 2 * Math.random()) * 5 + y0;

      var x11 = x0 + (x1 - x0) * 0.95;

      var y11 = y0 + (y1 - y0) * 0.95;

      var tn1 = new TWEEN.Tween(this.particles[idx][i].position).to({

        x: x11,

        y: y11

      }, t1)

      var tn2 = new TWEEN.Tween(this.particles[idx][i].position).to({

        x: x1,

        y: y1

      }, t2)

      tn1.chain(tn2)

      tn1.start()

      new TWEEN.Tween(this.particles[idx][i].rotation).to({

        z: "+3"

      }, t1).start()     

  }

  for (var i = 0; i < this.materials.length; ++i) {

    this.materials[i].opacity = 1;

    new TWEEN.Tween(this.materials[i]).to({ opacity: 0}, t2).delay(t1).start()

  }

}

}