Cesium-鼠标拾取椭球、地形、模型坐标点详解

var handler = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);  

handler.setInputAction(function(evt) { 

    var cartesian = viewer.camera.pickEllipsoid(evt.position, viewer.scene.globe.ellipsoid);  

    var cartographic = Cesium.Cartographic.fromCartesian(cartesian);  

    var lng = Cesium.Math.toDegrees(cartographic.longitude); // 经度值  

    var lat = Cesium.Math.toDegrees(cartographic.latitude); // 纬度值  

    var mapPosition = {

        x: lng, 

        y: lat,

        z: cartographic.height //cartographic.height 的值始终为零

    };

}, Cesium.ScreenSpaceEventType.LEFT_CLICK);

// 获取相机的高度

height = Math.ceil(viewer.camera.positionCartographic.height);

var handler = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);

// 设置鼠标移动事件的处理函数，这里负责监听 x, y 坐标值变化

handler.setInputAction(function(evt) {

    // 得到当前三维场景的椭球体，即地球

    var ellipsoid = scene.globe.ellipsoid;

    // 通过指定的椭球或者地图对应的坐标系，将鼠标的二维坐标转换为对应椭球体三维坐标

    cartesian = viewer.camera.pickEllipsoid(evt.endPosition, ellipsoid);

    // 将笛卡尔坐标转换为地理坐标

    var cartographic = ellipsoid.cartesianToCartographic(cartesian);

    // 将弧度转换为度的十进制表示

    lng = Cesium.Math.toDegrees(cartographic.longitude);

    lat = Cesium.Math.toDegrees(cartographic.latitude);

}, Cesium.ScreenSpaceEventType.MOUSE_MOVE)

var handler = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);  

handler.setInputAction(function(evt) {  

    var ray = viewer.camera.getPickRay(evt.position);  

    var cartesian = viewer.scene.globe.pick(ray, viewer.scene); 

    var cartographic = Cesium.Cartographic.fromCartesian(cartesian); 

    var lng = Cesium.Math.toDegrees(cartographic.longitude); // 经度值  

    var lat = Cesium.Math.toDegrees(cartographic.latitude); // 纬度值  

    var mapPosition = {

        x: lng,

        y: lat,

        z: cartographic.height //cartographic.height 的值为地形高度 

    }; 

}, Cesium.ScreenSpaceEventType.LEFT_CLICK);

var handler = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);  

handler.setInputAction(function(evt) {  

    var ray = viewer.camera.getPickRay(evt.position);  

    var cartesian = viewer.scene.globe.pick(ray, viewer.scene);  

    var cartographic = Cesium.Cartographic.fromCartesian(cartesian);  

    var lng = Cesium.Math.toDegrees(cartographic.longitude); // 经度值  

    var lat = Cesium.Math.toDegrees(cartographic.latitude); // 纬度值  

    //height 结果与 cartographic.height 相差无几，注意：cartographic.height 可以为 0，也就是说，可以根据经纬度计算出高程。  

    var height = viewer.scene.globe.getHeight(cartographic);  

    var mapPosition = {

        x: lng,

        y: lat,

        z: height.height //height 的值为地形高度

    };

}, Cesium.ScreenSpaceEventType.LEFT_CLICK);

var handler = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);  

handler.setInputAction(function(evt) {  

    var scene = viewer.scene;  

    if (scene.mode !== Cesium.SceneMode.MORPHING) {  

        var pickedObject = scene.pick(evt.position);  

        if (scene.pickPositionSupported && Cesium.defined(pickedObject) && pickedObject.node) {  

            var cartesian = viewer.scene.pickPosition(evt.position);  

            if (Cesium.defined(cartesian)) {  

                var cartographic = Cesium.Cartographic.fromCartesian(cartesian);  

                var lng = Cesium.Math.toDegrees(cartographic.longitude);  

                var lat = Cesium.Math.toDegrees(cartographic.latitude);  

                var height = cartographic.height; // 模型高度  

                mapPosition = {

                    x: lng,

                    y: lat,

                    z: height

                } 

            }  

        }  

    }  

}, Cesium.ScreenSpaceEventType.LEFT_CLICK);