Click cesium to obtain three-dimensional coordinates (longitude, latitude and elevation)

The following code applies to Get the terrain surface Three dimensional coordinates .

Be careful ：

1. It is applicable to picking points with terrain elevation
2. Not applicable to model 、 Tilt photography and other surface heights （ Please read my other article ）
3. Depth detection needs to be turned on depthTestAgainstTerrain = true.

//  Open depth detection 
viewer.scene.globe.depthTestAgainstTerrain = true

var handler = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);
handler.setInputAction(function (evt) {
    
  //  Return to one ray And an intersection of the earth's surface Cartesian3 coordinate .
  let ray = viewer.camera.getPickRay(evt.position);
  let cartesian = viewer.scene.globe.pick(ray, viewer.scene);
  // //  Space coordinates to world coordinates ( radian )
  let cartographic = Cesium.Cartographic.fromCartesian(cartesian);
  //  Radian to angle （ Longitude and latitude ）
  let lon = Cesium.Math.toDegrees(cartographic.longitude);  // Longitude value 
  let lat = Cesium.Math.toDegrees(cartographic.latitude); // Latitude value 
  //  Terrain height ( Just choose one of the following two )
  let height = cartographic.height;
  let height2 = viewer.scene.globe.getHeight(cartographic)
  console.log(' The longitude and latitude elevation is ：', {
     x: lon, y: lat, height: height, height2: height2 })
}, Cesium.ScreenSpaceEventType.LEFT_CLICK);

Cancel the left click event

handler = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);
handler.removeInputAction(Cesium.ScreenSpaceEventType.LEFT_CLICK)

Elevation part ：
cartographic.height and viewer.scene.globe.getHeight(cartographic) These two are elevations , You can see from the above figure that , There are some subtle differences , But it doesn't matter , You can use either of these two .