cesium add point, move point

The specific effects are as follows:

The main code is as follows:

// Add modeladdPic(longitude, latitude, altitude) {// When there are other entities on the earth, clear and addif (viewer.entities.values.length >= 1) {var existedId = viewer.entities.getById(viewer.entities.values[0].id);viewer.entities.remove(existedId);}this.paramForm.longitude = longitude;this.paramForm.latitude = latitude;this.paramForm.altitude = altitude;// add pointviewer.entities.add({// the position of the pointposition : Cesium.Cartesian3.fromDegrees(longitude, latitude, altitude),//pointpoint : {pixelSize : 10,//The size of the pointcolor : Cesium.Color.RED,//The color of the pointoutlineColor:Cesium.Color.YELLOW,//Outer circle coloroutlineWidth:5,//Outer circle size}});},

I mainly control the change of latitude and longitude through the input box

The following event is triggered when the latitude and longitude height changes

angleChange(flag, val) {let num = parseInt(val);if (flag == "lng") {// when longitude changesthis.addPic(num, this.paramForm.latitude, this.paramForm.altitude);} else if (flag == "lat") {// when the latitude changesthis.addPic(this.paramForm.longitude, num, this.paramForm.altitude);} else if (flag == "alt") {// when the height (range) changesthis.addPic(this.paramForm.longitude, this.paramForm.latitude, num);}},