Cesium测量距离和面积、位置坐标

Cesium测量距离和面积

直接上代码，下面两个函数已经封装好，可以直接调用；有疑问请加群讨论：1047907561

//线长度测量
function measureLine(viewer) {
    var handler = new Cesium.ScreenSpaceEventHandler(viewer.scene._imageryLayerCollection);
    var positions = [];
    var poly = null;
    var distance = 0;
    var cartesian = null;
    var floatingPoint;
    var labelPt;
    handler.setInputAction(function (movement) {
        let ray = viewer.camera.getPickRay(movement.endPosition);
        cartesian = viewer.scene.globe.pick(ray, viewer.scene);
        if (!Cesium.defined(cartesian)) //跳出地球时异常
            return;
        if (positions.length >= 2) {
            if (!Cesium.defined(poly)) {
                poly = new PolyLinePrimitive(positions);
            } else {
                positions.pop();
                positions.push(cartesian);
            }
        }
    }, Cesium.ScreenSpaceEventType.MOUSE_MOVE);

    handler.setInputAction(function (movement) {
        let ray = viewer.camera.getPickRay(movement.position);
        cartesian = viewer.scene.globe.pick(ray, viewer.scene);
        if (!Cesium.defined(cartesian)) //跳出地球时异常
            return;
        if (positions.length == 0) {
            positions.push(cartesian.clone());
        }
        positions.push(cartesian);
        //记录鼠标单击时的节点位置，异步计算贴地距离
        labelPt = positions[positions.length - 1];
        if (positions.length > 2) {
            getSpaceDistance(positions);
        } else if (positions.length == 2) {
            //在三维场景中添加Label
            floatingPoint = viewer.entities.add({
                name: '空间距离',
                position: labelPt,
                point: {
                    pixelSize: 5,
                    color: Cesium.Color.RED,
                    outlineColor: Cesium.Color.WHITE,
                    outlineWidth: 2,
                }
            });
        }
    }, Cesium.ScreenSpaceEventType.LEFT_CLICK);

    handler.setInputAction(function (movement) {
        handler.destroy(); //关闭事件句柄
        handler = undefined;
        positions.pop(); //最后一个点无效
        if (positions.length == 1)
            viewer.entities.remove(floatingPoint);

    }, Cesium.ScreenSpaceEventType.RIGHT_CLICK);

    var PolyLinePrimitive = (function () {
        function _(positions) {
            this.options = {
                name: '直线',
                polyline: {
                    show: true,
                    positions: [],
                    material: Cesium.Color.CHARTREUSE,
                     5,
                    clampToGround: true
                }
            };
            this.positions = positions;
            this._init();
        }

        _.prototype._init = function () {
            var _self = this;
            var _update = function () {
                return _self.positions;
            };
            //实时更新polyline.positions
            this.options.polyline.positions = new Cesium.CallbackProperty(_update, false);
            var addedEntity = viewer.entities.add(this.options);
        };

        return _;
    })();

    //空间两点距离计算函数
    function getSpaceDistance(positions) {
        console.log(22)
        //只计算最后一截，与前面累加
        //因move和鼠标左击事件，最后两个点坐标重复
        var i = positions.length - 3;
        var point1cartographic = Cesium.Cartographic.fromCartesian(positions[i]);
        var point2cartographic = Cesium.Cartographic.fromCartesian(positions[i + 1]);
        getTerrainDistance(point1cartographic, point2cartographic);
    }

    function getTerrainDistance(point1cartographic, point2cartographic) {
        var geodesic = new Cesium.EllipsoidGeodesic();
        geodesic.setEndPoints(point1cartographic, point2cartographic);
        var s = geodesic.surfaceDistance;
        var cartoPts = [point1cartographic];
        for (var jj = 1000; jj < s; jj += 1000) {　　//分段采样计算距离
            var cartoPt = geodesic.interpolateUsingSurfaceDistance(jj);
            cartoPts.push(cartoPt);
        }
        cartoPts.push(point2cartographic);
        //返回两点之间的距离
        var promise = Cesium.sampleTerrain(viewer.terrainProvider, 8, cartoPts);
        Cesium.when(promise, function (updatedPositions) {
            for (var jj = 0; jj < updatedPositions.length - 1; jj++) {
                var geoD = new Cesium.EllipsoidGeodesic();
                geoD.setEndPoints(updatedPositions[jj], updatedPositions[jj + 1]);
                var innerS = geoD.surfaceDistance;
                innerS = Math.sqrt(Math.pow(innerS, 2) + Math.pow(updatedPositions[jj + 1].height - updatedPositions[jj].height, 2));
                distance += innerS;
            }
            //在三维场景中添加Label
            var lon1 = viewer.scene.globe.ellipsoid.cartesianToCartographic(labelPt).longitude;
            var lat1 = viewer.scene.globe.ellipsoid.cartesianToCartographic(labelPt).latitude;
            var lonLat = "(" + Cesium.Math.toDegrees(lon1).toFixed(2) + "," + Cesium.Math.toDegrees(lat1).toFixed(2) + ")";
            var textDisance = distance.toFixed(2) + "米";
            if (distance > 10000)
                textDisance = (distance / 1000.0).toFixed(2) + "千米";
            floatingPoint = viewer.entities.add({
                name: '贴地距离',
                position: labelPt,
                point: {
                    pixelSize: 5,
                    color: Cesium.Color.RED,
                    outlineColor: Cesium.Color.WHITE,
                    outlineWidth: 2,
                },
                label: {
                    text: lonLat + textDisance,
                    font: '18px sans-serif',
                    fillColor: Cesium.Color.GOLD,
                    style: Cesium.LabelStyle.FILL_AND_OUTLINE,
                    outlineWidth: 2,
                    verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
                    pixelOffset: new Cesium.Cartesian2(20, -20),
                }
            });
        });
    }
}

//面积测量
function measurePolygn(viewer) {
    // 鼠标事件
    var handler = new Cesium.ScreenSpaceEventHandler(viewer.scene._imageryLayerCollection);
    var positions = [];
    var tempPoints = [];
    var polygon = null;
    var cartesian = null;
    var floatingPoint;//浮动点
    handler.setInputAction(function (movement) {
        let ray = viewer.camera.getPickRay(movement.endPosition);
        cartesian = viewer.scene.globe.pick(ray, viewer.scene);
        positions.pop();//移除最后一个
        positions.push(cartesian);
        if (positions.length >= 2) {
            var dynamicPositions = new Cesium.CallbackProperty(function () {
                return new Cesium.PolygonHierarchy(positions);
                return positions;
            }, false);
            polygon = PolygonPrimitive(dynamicPositions);
        }
    }, Cesium.ScreenSpaceEventType.MOUSE_MOVE);

    handler.setInputAction(function (movement) {
        let ray = viewer.camera.getPickRay(movement.position);
        cartesian = viewer.scene.globe.pick(ray, viewer.scene);
        if (positions.length == 0) {
            positions.push(cartesian.clone());
        }
        positions.push(cartesian);
        //在三维场景中添加点
        var cartographic = Cesium.Cartographic.fromCartesian(positions[positions.length - 1]);
        var longitudeString = Cesium.Math.toDegrees(cartographic.longitude);
        var latitudeString = Cesium.Math.toDegrees(cartographic.latitude);
        var heightString = cartographic.height;
        var labelText = "(" + longitudeString.toFixed(2) + "," + latitudeString.toFixed(2) + ")";
        tempPoints.push({ lon: longitudeString, lat: latitudeString, hei: heightString });
        floatingPoint = viewer.entities.add({
            name: '多边形面积',
            position: positions[positions.length - 1],
            point: {
                pixelSize: 5,
                color: Cesium.Color.RED,
                outlineColor: Cesium.Color.WHITE,
                outlineWidth: 2,
                heightReference: Cesium.HeightReference.CLAMP_TO_GROUND
            },
            label: {
                text: labelText,
                font: '18px sans-serif',
                fillColor: Cesium.Color.GOLD,
                style: Cesium.LabelStyle.FILL_AND_OUTLINE,
                outlineWidth: 2,
                verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
                pixelOffset: new Cesium.Cartesian2(20, -20),
            }
        });
    }, Cesium.ScreenSpaceEventType.LEFT_CLICK);
    handler.setInputAction(function (movement) {
        handler.destroy();
        positions.pop();
        var textArea = getArea(tempPoints) + "平方公里";
        viewer.entities.add({
            name: '多边形面积',
            position: positions[positions.length - 1],
            label: {
                text: textArea,
                font: '18px sans-serif',
                fillColor: Cesium.Color.GOLD,
                style: Cesium.LabelStyle.FILL_AND_OUTLINE,
                outlineWidth: 2,
                verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
                pixelOffset: new Cesium.Cartesian2(20, -40),
                heightReference: Cesium.HeightReference.CLAMP_TO_GROUND
            }
        });
    }, Cesium.ScreenSpaceEventType.RIGHT_CLICK);
    var radiansPerDegree = Math.PI / 180.0;//角度转化为弧度(rad)
    var degreesPerRadian = 180.0 / Math.PI;//弧度转化为角度
    //计算多边形面积
    function getArea(points) {
        var res = 0;
        //拆分三角曲面
        for (var i = 0; i < points.length - 2; i++) {
            var j = (i + 1) % points.length;
            var k = (i + 2) % points.length;
            var totalAngle = Angle(points[i], points[j], points[k]);
            var dis_temp1 = distance(positions[i], positions[j]);
            var dis_temp2 = distance(positions[j], positions[k]);
            res += dis_temp1 * dis_temp2 * Math.abs(Math.sin(totalAngle));
        }
        return (res / 1000000.0).toFixed(4);
    }

    /*角度*/
    function Angle(p1, p2, p3) {
        var bearing21 = Bearing(p2, p1);
        var bearing23 = Bearing(p2, p3);
        var angle = bearing21 - bearing23;
        if (angle < 0) {
            angle += 360;
        }
        return angle;
    }
    /*方向*/
    function Bearing(from, to) {
        var lat1 = from.lat * radiansPerDegree;
        var lon1 = from.lon * radiansPerDegree;
        var lat2 = to.lat * radiansPerDegree;
        var lon2 = to.lon * radiansPerDegree;
        var angle = -Math.atan2(Math.sin(lon1 - lon2) * Math.cos(lat2), Math.cos(lat1) * Math.sin(lat2) - Math.sin(lat1) * Math.cos(lat2) * Math.cos(lon1 - lon2));
        if (angle < 0) {
            angle += Math.PI * 2.0;
        }
        angle = angle * degreesPerRadian;//角度
        return angle;
    }

    function PolygonPrimitive(positions) {
        polygon = viewer.entities.add({
            polygon: {
                hierarchy: positions,
                material: Cesium.Color.GREEN.withAlpha(0.1),
            }
        });

    }

    function distance(point1, point2) {
        var point1cartographic = Cesium.Cartographic.fromCartesian(point1);
        var point2cartographic = Cesium.Cartographic.fromCartesian(point2);
        /**根据经纬度计算出距离**/
        var geodesic = new Cesium.EllipsoidGeodesic();
        geodesic.setEndPoints(point1cartographic, point2cartographic);
        var s = geodesic.surfaceDistance;
        //返回两点之间的距离
        s = Math.sqrt(Math.pow(s, 2) + Math.pow(point2cartographic.height - point1cartographic.height, 2));
        return s;
    }
}

measureLine(viewer)
measurePolygn(viewer) 

//获取坐标点

// handler.setInputAction(function (event) {

//     viewer.scene.globe.depthTestAgainstTerrain = true;

//     var earthPosition = viewer.scene.pickPosition(event.position);

//     console.log(earthPosition)

//     //3.地标坐标：获取点击处地球表面的世界坐标，不包括模型、倾斜摄影表面

//     var ray = viewer.camera.getPickRay(event.position);

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

//     if (Cesium.defined(earthPosition)) {

//         console.log(earthPosition);

//     }

// }, Cesium.ScreenSpaceEventType.LEFT_CLICK);

/*

    vue中整理好

*/

    // //距离计算

    // measureLine(viewer) {

    //     var handler = new Cesium.ScreenSpaceEventHandler(

    //       this.viewer.scene._imageryLayerCollection

    //     );

    //     var positions = [];

    //     var poly = null;

    //     var distance = 0;

    //     var cartesian = null;

    //     var floatingPoint;

    //     var labelPt;

    //     var that = this;

    //     handler.setInputAction(function(movement) {

    //       let ray = that.viewer.camera.getPickRay(movement.endPosition);

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

    //       if (!Cesium.defined(cartesian))

    //         //跳出地球时异常

    //         return;

    //       if (positions.length >= 2) {

    //         if (!Cesium.defined(poly)) {

    //           poly = new PolyLinePrimitive(positions);

    //         } else {

    //           positions.pop();

    //           positions.push(cartesian);

    //         }

    //       }

    //     }, Cesium.ScreenSpaceEventType.MOUSE_MOVE);

  

    //     handler.setInputAction(function(movement) {

    //       let ray = that.viewer.camera.getPickRay(movement.position);

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

    //       if (!that.Cesium.defined(cartesian))

    //         //跳出地球时异常

    //         return;

    //       if (positions.length == 0) {

    //         positions.push(cartesian.clone());

    //       }

    //       positions.push(cartesian);

    //       //记录鼠标单击时的节点位置，异步计算贴地距离

    //       labelPt = positions[positions.length - 1];

    //       if (positions.length > 2) {

    //         getSpaceDistance(positions);

    //       } else if (positions.length == 2) {

    //         //在三维场景中添加Label

    //         floatingPoint = that.viewer.entities.add({

    //           name: "空间距离",

    //           position: labelPt,

    //           point: {

    //             pixelSize: 5,

    //             color: Cesium.Color.RED,

    //             outlineColor: Cesium.Color.WHITE,

    //             outlineWidth: 2

    //           }

    //         });

    //       }

    //     }, Cesium.ScreenSpaceEventType.LEFT_CLICK);

  

    //     handler.setInputAction(function(movement) {

    //       handler.destroy(); //关闭事件句柄

    //       handler = undefined;

    //       positions.pop(); //最后一个点无效

    //       if (positions.length == 1) that.viewer.entities.remove(floatingPoint);

    //     }, Cesium.ScreenSpaceEventType.RIGHT_CLICK);

  

    //     var PolyLinePrimitive = (function() {

    //       function _(positions) {

    //         this.options = {

    //           name: "直线",

    //           polyline: {

    //             show: true,

    //             positions: [],

    //             material: Cesium.Color.CHARTREUSE,

    //              5,

    //             clampToGround: true

    //           }

    //         };

    //         this.positions = positions;

    //         this._init();

    //       }

  

    //       _.prototype._init = function() {

    //         var _self = this;

    //         var _update = function() {

    //           return _self.positions;

    //         };

    //         //实时更新polyline.positions

    //         this.options.polyline.positions = new Cesium.CallbackProperty(

    //           _update,

    //           false

    //         );

    //         var addedEntity = that.viewer.entities.add(this.options);

    //       };

  

    //       return _;

    //     })();

  

    //     //空间两点距离计算函数

    //     function getSpaceDistance(positions) {

    //       //只计算最后一截，与前面累加

    //       //因move和鼠标左击事件，最后两个点坐标重复

    //       var i = positions.length - 3;

    //       var point1cartographic = that.Cesium.Cartographic.fromCartesian(

    //         positions[i]

    //       );

    //       var point2cartographic = that.Cesium.Cartographic.fromCartesian(

    //         positions[i + 1]

    //       );

    //       getTerrainDistance(point1cartographic, point2cartographic);

    //     }

  

    //     function getTerrainDistance(point1cartographic, point2cartographic) {

    //       var geodesic = new Cesium.EllipsoidGeodesic();

    //       geodesic.setEndPoints(point1cartographic, point2cartographic);

    //       var s = geodesic.surfaceDistance;

    //       var cartoPts = [point1cartographic];

    //       for (var jj = 1000; jj < s; jj += 1000) {

    //         //分段采样计算距离

    //         var cartoPt = geodesic.interpolateUsingSurfaceDistance(jj);

    //         cartoPts.push(cartoPt);

    //       }

    //       cartoPts.push(point2cartographic);

    //       //返回两点之间的距离

    //       var promise = that.Cesium.sampleTerrain(

    //         that.viewer.terrainProvider,

    //         8,

    //         cartoPts

    //       );

    //       Cesium.when(promise, function(updatedPositions) {

    //         for (var jj = 0; jj < updatedPositions.length - 1; jj++) {

    //           var geoD = new Cesium.EllipsoidGeodesic();

    //           geoD.setEndPoints(updatedPositions[jj], updatedPositions[jj + 1]);

    //           var innerS = geoD.surfaceDistance;

    //           innerS = Math.sqrt(

    //             Math.pow(innerS, 2) +

    //               Math.pow(

    //                 updatedPositions[jj + 1].height - updatedPositions[jj].height,

    //                 2

    //               )

    //           );

    //           distance += innerS;

    //         }

    //         //在三维场景中添加Label

    //         var lon1 = that.viewer.scene.globe.ellipsoid.cartesianToCartographic(

    //           labelPt

    //         ).longitude;

    //         var lat1 = that.viewer.scene.globe.ellipsoid.cartesianToCartographic(

    //           labelPt

    //         ).latitude;

    //         var lonLat =

    //           "(" +

    //           Cesium.Math.toDegrees(lon1).toFixed(2) +

    //           "," +

    //           Cesium.Math.toDegrees(lat1).toFixed(2) +

    //           ")";

    //         var textDisance = distance.toFixed(2) + "米";

    //         if (distance > 10000)

    //           textDisance = (distance / 1000.0).toFixed(2) + "千米";

    //         floatingPoint = that.viewer.entities.add({

    //           name: "贴地距离",

    //           position: labelPt,

    //           point: {

    //             pixelSize: 5,

    //             color: Cesium.Color.RED,

    //             outlineColor: Cesium.Color.WHITE,

    //             outlineWidth: 2

    //           },

    //           label: {

    //             text: lonLat + textDisance,

    //             font: "18px sans-serif",

    //             fillColor: Cesium.Color.GOLD,

    //             style: Cesium.LabelStyle.FILL_AND_OUTLINE,

    //             outlineWidth: 2,

    //             verticalOrigin: Cesium.VerticalOrigin.BOTTOM,

    //             pixelOffset: new Cesium.Cartesian2(20, -20)

    //           }

    //         });

    //       });

    //     }

    //   },

  

    //   //面积计算

    //   measurePolygn(viewer) {

    //     // 鼠标事件

    //     var handler = new Cesium.ScreenSpaceEventHandler(

    //       viewer.scene._imageryLayerCollection

    //     );

    //     var positions = [];

    //     var tempPoints = [];

    //     var polygon = null;

    //     var cartesian = null;

    //     var floatingPoint; //浮动点

    //     var that = this;

    //     handler.setInputAction(function(movement) {

    //       let ray = that.viewer.camera.getPickRay(movement.endPosition);

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

    //       positions.pop(); //移除最后一个

    //       positions.push(cartesian);

    //       if (positions.length >= 2) {

    //         var dynamicPositions = new Cesium.CallbackProperty(function() {

    //           return new Cesium.PolygonHierarchy(positions);

    //           return positions;

    //         }, false);

    //         polygon = PolygonPrimitive(dynamicPositions);

    //       }

    //     }, Cesium.ScreenSpaceEventType.MOUSE_MOVE);

  

    //     handler.setInputAction(function(movement) {

    //       let ray = that.viewer.camera.getPickRay(movement.position);

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

    //       if (positions.length == 0) {

    //         positions.push(cartesian.clone());

    //       }

    //       positions.push(cartesian);

    //       //在三维场景中添加点

    //       var cartographic = that.Cesium.Cartographic.fromCartesian(

    //         positions[positions.length - 1]

    //       );

    //       var longitudeString = that.Cesium.Math.toDegrees(

    //         cartographic.longitude

    //       );

    //       var latitudeString = that.Cesium.Math.toDegrees(cartographic.latitude);

    //       var heightString = cartographic.height;

    //       var labelText =

    //         "(" +

    //         longitudeString.toFixed(2) +

    //         "," +

    //         latitudeString.toFixed(2) +

    //         ")";

    //       tempPoints.push({

    //         lon: longitudeString,

    //         lat: latitudeString,

    //         hei: heightString

    //       });

    //       floatingPoint = that.viewer.entities.add({

    //         name: "多边形面积",

    //         position: positions[positions.length - 1],

    //         point: {

    //           pixelSize: 5,

    //           color: Cesium.Color.RED,

    //           outlineColor: Cesium.Color.WHITE,

    //           outlineWidth: 2,

    //           heightReference: Cesium.HeightReference.CLAMP_TO_GROUND

    //         },

    //         label: {

    //           text: labelText,

    //           font: "18px sans-serif",

    //           fillColor: Cesium.Color.GOLD,

    //           style: Cesium.LabelStyle.FILL_AND_OUTLINE,

    //           outlineWidth: 2,

    //           verticalOrigin: Cesium.VerticalOrigin.BOTTOM,

    //           pixelOffset: new Cesium.Cartesian2(20, -20)

    //         }

    //       });

    //     }, Cesium.ScreenSpaceEventType.LEFT_CLICK);

    //     handler.setInputAction(function(movement) {

    //       handler.destroy();

    //       positions.pop();

    //       var textArea = getArea(tempPoints) + "平方公里";

    //       that.viewer.entities.add({

    //         name: "多边形面积",

    //         position: positions[positions.length - 1],

    //         label: {

    //           text: textArea,

    //           font: "18px sans-serif",

    //           fillColor: Cesium.Color.GOLD,

    //           style: Cesium.LabelStyle.FILL_AND_OUTLINE,

    //           outlineWidth: 2,

    //           verticalOrigin: Cesium.VerticalOrigin.BOTTOM,

    //           pixelOffset: new Cesium.Cartesian2(20, -40),

    //           heightReference: Cesium.HeightReference.CLAMP_TO_GROUND

    //         }

    //       });

    //     }, Cesium.ScreenSpaceEventType.RIGHT_CLICK);

    //     var radiansPerDegree = Math.PI / 180.0; //角度转化为弧度(rad)

    //     var degreesPerRadian = 180.0 / Math.PI; //弧度转化为角度

    //     //计算多边形面积

    //     function getArea(points) {

    //       var res = 0;

    //       //拆分三角曲面

    //       for (var i = 0; i < points.length - 2; i++) {

    //         var j = (i + 1) % points.length;

    //         var k = (i + 2) % points.length;

    //         var totalAngle = Angle(points[i], points[j], points[k]);

    //         var dis_temp1 = distance(positions[i], positions[j]);

    //         var dis_temp2 = distance(positions[j], positions[k]);

    //         res += dis_temp1 * dis_temp2 * Math.abs(Math.sin(totalAngle));

    //       }

    //       return (res / 1000000.0).toFixed(4);

    //     }

  

    //     /*角度*/

    //     function Angle(p1, p2, p3) {

    //       var bearing21 = Bearing(p2, p1);

    //       var bearing23 = Bearing(p2, p3);

    //       var angle = bearing21 - bearing23;

    //       if (angle < 0) {

    //         angle += 360;

    //       }

    //       return angle;

    //     }

    //     /*方向*/

    //     function Bearing(from, to) {

    //       var lat1 = from.lat * radiansPerDegree;

    //       var lon1 = from.lon * radiansPerDegree;

    //       var lat2 = to.lat * radiansPerDegree;

    //       var lon2 = to.lon * radiansPerDegree;

    //       var angle = -Math.atan2(

    //         Math.sin(lon1 - lon2) * Math.cos(lat2),

    //         Math.cos(lat1) * Math.sin(lat2) -

    //           Math.sin(lat1) * Math.cos(lat2) * Math.cos(lon1 - lon2)

    //       );

    //       if (angle < 0) {

    //         angle += Math.PI * 2.0;

    //       }

    //       angle = angle * degreesPerRadian; //角度

    //       return angle;

    //     }

  

    //     function PolygonPrimitive(positions) {

    //       polygon = that.viewer.entities.add({

    //         polygon: {

    //           hierarchy: positions,

    //           material: Cesium.Color.GREEN.withAlpha(0.1)

    //         }

    //       });

    //     }

  

    //     function distance(point1, point2) {

    //       var point1cartographic = that.Cesium.Cartographic.fromCartesian(point1);

    //       var point2cartographic = that.Cesium.Cartographic.fromCartesian(point2);

    //       /**根据经纬度计算出距离**/

    //       var geodesic = new Cesium.EllipsoidGeodesic();

    //       geodesic.setEndPoints(point1cartographic, point2cartographic);

    //       var s = geodesic.surfaceDistance;

    //       //返回两点之间的距离

    //       s = Math.sqrt(

    //         Math.pow(s, 2) +

    //           Math.pow(point2cartographic.height - point1cartographic.height, 2)

    //       );

    //       return s;

    //     }

    //   }