怎么把3dtiles加载到准确的位置啊

案例下来看看 https://cesiumjs.org/Cesium/Build/Apps/Sandcastle/

我就选了一个顶点

//鼠标点击监听，获取屏幕坐标-弧度制-经纬度
 	handler.setInputAction(function(click){
 	    var screenX=click.position.x;
        var screenY=click.position.y;
       // console.log("像素:"+screenX+"："+ screenY)
        var cartesianPosition = viewer.camera.pickEllipsoid (new Cesium. Cartesian2 ( screenX,screenY));
var cartographicPosition = Cesium.Ellipsoid.WGS84. cartesianToCartographic (cartesianPosition);  //结果是弧度制
var longitudeString = Cesium.Math.toDegrees(cartographicPosition.longitude);
var latitudeString = Cesium.Math.toDegrees(cartographicPosition.latitude);
//	console.log(longitudeString)
//	console.log(latitudeString);
 	},Cesium.ScreenSpaceEventType.LEFT_CLICK);

@admin #1楼 这代码不行啊兄弟，模型直接找不到了