Cesium entity闪烁（点、面以及billboard）

entity的闪烁主要是通过回调函数​​CallbackProperty​​，控制样式改变或是否显示

1. 点的闪烁

function f2(){
   
     
     
  var x=1;
  var flog=true;
  viewer.entities.add({
   
     
     
    name:"圆点point闪烁",
    position:Cesium.Cartesian3.fromDegrees(116.20+0.03,39.53+0.03,0),
    point : {
   
     
     
      show : true, // default
      color :new Cesium.CallbackProperty(function () {
   
     
     
        if(flog){
   
     
     
          x=x-0.05;
          if(x<=0){
   
     
     
            flog=false;
          }
          }else{
   
     
     
            x=x+0.05;
            if(x>=1){
   
     
     
            flog=true;
            }
          }
          return Cesium.Color.RED.withAlpha(x);
        },false),
      pixelSize : 10, // default: 1
      outlineWidth :0
    }
  });
}

2. 面的闪烁

function f1() {
   
     
     
    var x = 1;
    var flog = true;
    viewer.entities.add({
   
     
     
        name: "圆形区域闪烁",
        position: Cesium.Cartesian3.fromDegrees(116.20, 39.53, 0),
        ellipse: {
   
     
     
            semiMinorAxis: 2000.0,
            semiMajorAxis: 2000.0,
            height: 0,
            material: new Cesium.ColorMaterialProperty(new Cesium.CallbackProperty(function () {
   
     
     
                if (flog) {
   
     
     
                    x = x - 0.05;
                    if (x <= 0) {
   
     
     
                        flog = false;
                    }
                } else {
   
     
     
                    x = x + 0.05;
                    if (x >= 1) {
   
     
     
                        flog = true;
                    }
                }
                console.log(x)
                return Cesium.Color.RED.withAlpha(x);
            }, false))
        }
    });
}

3. billboard图片的闪烁

function f1() {
   
     
     
var x = 1;
    var flog = true;
    viewer.entities.add({
   
     
     
        name: 'singleWarning',
        position: Cesium.Cartesian3.fromDegrees(116.20, 39.53),
        billboard: {
   
     
     
            image: '预警定位.png',
            name: 'singleWarning',
            show: new Cesium.CallbackProperty(function () {
   
     
     
                if (flog) {
   
     
     
                    x = x - 0.05;
                    if (x <= 0) {
   
     
     
                        flog = false;
                    }
                } else {
   
     
     
                    x = x + 0.05;
                    if (x >= 1) {
   
     
     
                        flog = true;
                    }
                }
                return x >= 0.5;
            },false),
            width: 100,
            height: 100,
            distanceDisplayCondition: new Cesium.DistanceDisplayCondition(0, 6.8e10)
        },
    })
}

这里的方法其实就是通过CallbackProperty控制show为true或者false，如果x>=0.5，就是true，反之为false