cesium粒子爆炸效果

效果：

//添加爆炸模型
    window.swpecesium.addEntity.addModel({
      id: "model",
      position: {
        lon: 116.34516786934411,
        lat: 39.99753297677145,
      },
      config: {
        url: "./model/baozha/scene.gltf",
        minSize: 200,
        maxSize: 300,
      },
    });

  var scene = viewer.scene;
  scene.debugShowFramesPerSecond = true;
  //粒子系统的起点，发射源
  var staticPosition = Cesium.Cartesian3.fromDegrees(
    116.34516786934411,
    39.99753297677145,
    3.614538127977399
  );
  var entity44 = viewer.entities.add({
    position: staticPosition,
    distanceDisplayCondition: new Cesium.DistanceDisplayCondition(50, 30000), //相机与与物体的最大最小可见距离
    disableDepthTestDistance: 10000, //相机的深度遮挡
  });
  function computeModelMatrix(entity, time) {
    var position = Cesium.Property.getValueOrUndefined(entity.position, time);
    let modelMatrix = Cesium.Transforms.eastNorthUpToFixedFrame(position);

    return modelMatrix;
  }

  function computeEmitterModelMatrix() {
    let hpr = Cesium.HeadingPitchRoll.fromDegrees(0, 0, 0);
    let trs = new Cesium.TranslationRotationScale();
    trs.translation = Cesium.Cartesian3.fromElements(2.5, 4, 1);
    trs.rotation = Cesium.Quaternion.fromHeadingPitchRoll(hpr);
    let result = Cesium.Matrix4.fromTranslationRotationScale(trs);
    return result;
  }
  // 创建粒子
  viewer.scene.primitives.add(
    new Cesium.ParticleSystem({
      image: "./imgs/fire3.png", //1 (2) fire3 粒子图像
      imageSize: new Cesium.Cartesian2(10.0, 10.0), //粒子图像尺寸（以像素为单位）的minimumImageSize和maximumImageSize
      startColor: Cesium.Color.RED.withAlpha(0.7), //粒子在其生命初期的颜色
      endColor: Cesium.Color.YELLOW.withAlpha(0.3), //粒子在其生命结束的颜色
      minimumSpeed: 1, //最小速度
      maximumSpeed: 2, //最大速度
      startScale: 10, //粒子图像的初始比例
      endScale: 40, //粒子图像的结束比例
      minimumParticleLife: 1, //粒子生命的可能持续时间的最小范围
      maximumParticleLife: 6, //粒子生命的可能持续时间的最大范围
      emissionRate: 4, //每秒要发射的粒子数
      //粒子系统生命周期内，按照指定周期，爆发一定数量的粒子。三个参数（time，minimum，maximum）
      bursts: [
        // 爆炸出的粒子的密度
        new Cesium.ParticleBurst({
          time: 5.0,
          minimum: 10,
          maximum: 100,
        }),
        new Cesium.ParticleBurst({
          time: 10.0,
          minimum: 50,
          maximum: 100,
        }),
        new Cesium.ParticleBurst({
          time: 15.0,
          minimum: 200,
          maximum: 300,
        }),
      ],
      lifetime: 10.0, //发射粒子的时间
      emitter: new Cesium.CircleEmitter(5.0), //粒子发射器 BoxEmitter:盒形发射器;CircleEmitter:圆形发射器;ConeEmitter:锥形发射器;SphereEmitter:球形发射器
      // 粒子发射器一般都会都会相对于某一个entity或primitive进行定位，用到的就是modelMatrix
      modelMatrix: computeModelMatrix(entity44, Cesium.JulianDate.now()), //从模型转换为世界坐标的4x4转换矩阵
      emitterModelMatrix: computeEmitterModelMatrix(), // 粒子发射器模型矩阵，在粒子系统的局部坐标系内变换粒子发射器。
    })
  );

  viewer.camera.setView({
    destination: Cesium.Cartesian3.fromDegrees(
      116.34485552299206,
      39.99754814959118,
      500.0
    ),
  });