开源三维地球GIS引擎Cesium常用功能的开发

    Cesium是一个非常优秀的三维地球GIS引擎（开源且免费）。能够加载各种符合标准的地图图层，瓦片图、矢量图等都支持。支持3DMax等建模软件生成的obj文件，支持通用的GIS计算；支持DEM高程图。测试中的3D-Tiles分支还支持倾斜摄影生成的城市三维建筑群。国内许多三维GIS产品都基于Cesium进行封装（包括一些大厂）。因为工作关系，我对Cesium的一些基本GIS功能进行了研究，特此记录下来。

     (源码： https://github.com/thanksqq/CesiumExample 请注意现在最新的cesium版本API可能有些不同)

 

    如上图，这是一个给市政GIS\BIM管理平台做的原型，GIS部分使用Cesium，BIM部分使用第三方商业引擎。GIS控制宏观、BIM支持微观（现在还没有什么好的引擎能做到GIS\BIM的无缝切换）。

常用功能介绍：

• 卫星\矢量地图切换

     

 

    我这里使用的是天地图提供的服务，卫星地图和矢量地图分别调用不同的接口，卫星地图显示效果如上图，矢量地图显示如下图：

 

• 道路及基本标注

    点“道路及基本标注”后，将路名等显示并加载在原先的图层上

 

 

• 加标记点

首先在地图上点击需要加点的位置，然后在弹出框内选取颜色，设置提示文字和显示内容，点击保存；可以添加多个标记。

 

 

• 绘制线段

连续点击地图两次就可以绘制线段（可绘制折线）

 

• 绘制圆形

支持绘制多个圆形，每个圆形随机颜色，能够显示园的半径、面积等

 

• 绘制多边形

 

    连续点击地图上的点，再右键闭合，就可以绘制多边形，能够计算多边形每一边的边长、总面积等

 

• 保存视角、跳转视角

保存当前的视角；输入经纬度，跳转到指定位置

 

• 隐藏、加载模型

可以动态加载、隐藏三维模型（为了便于演示，所有的模型均放大了几百倍）；地图上的绘制功能对所有模型都有效，包含在范围内的模型会自动高亮并显示；点选模型能自动居中并提示是否跳转到BIM模型显示（BIM模型也是基于三维WebGL的）

 

• 搜索

可以根据输入的关键词进行搜索，使用百度或者高德的API，或者使用天地图的API，搜索后进行定位，只是百度、高德、天地图等用的是不同的坐标系，转换非常麻烦。

 

• 清除绘制

清除所有绘制的部分

 

以上功能只要再完善下，封装下就可以成为一个很不错的三维GIS项目基础平台了，附我们公司做的GIS+BIM的产品截图，使用了3D-Tiles：）

 

附：示例程序的js部分代码

    var bimEngine; var msgControl; var toolbar; var fileControl; var spaceControl; var domainControl; var propertyControl; var searchControl; var markControl;
    var storeyControl; var roamingControl; var bimevent;
    
    var viewer = new Cesium.Viewer("cesiumContainer", {
        animation: false, //是否显示动画控件
        baseLayerPicker: false, //是否显示图层选择控件
        geocoder: true, //是否显示地名查找控件
        timeline: false, //是否显示时间线控件
        sceneModePicker: true, //是否显示投影方式控件
        navigationHelpButton: false, //是否显示帮助信息控件
        infoBox: true, //是否显示点击要素之后显示的信息
        imageryProvider: new Cesium.WebMapTileServiceImageryProvider({
            url: "http://t0.tianditu.com/img_w/wmts?service=wmts&request=GetTile&version=1.0.0&LAYER=img&tileMatrixSet=w&TileMatrix={TileMatrix}&TileRow={TileRow}&TileCol={TileCol}&style=default&format=tiles",
            layer: "tdtBasicLayer",
            style: "default",
            format: "image/jpeg",
            tileMatrixSetID: "GoogleMapsCompatible",
            show: false
        })
    });
    var scene = viewer.scene;
    var pinBuilder = new Cesium.PinBuilder();

    var vecLayer = null, roadLayer = null, electricLayers = null;
    
    var getEnumPropertyNames = function(obj) {
        var props = [];
        for (prop in obj) {
            props.push(prop + ': ' + obj[prop]);
        }
        return props;
    }

    var models = new Array();
    models[0] = { id: 'house1', name: 'house1', url: '../SampleData/house/house1.gltf', lon: 121.41, lat: 31.22, height: 0, pid: '4e027d42-f033-4bab-87f1-e34c8860b90e' };
    models[1] = { id: 'house2', name: 'house2', url: '../SampleData/house/house2.gltf', lon: 121.42, lat: 31.21, height: 0, pid: '918dcfaa-4568-4468-ba03-e379deaa99b7' };
    models[2] = { id: 'house3', name: 'house3', url: '../SampleData/house/house3.gltf', lon: 121.43, lat: 31.20, height: 0, pid: '2071736b-0054-4041-ad34-34f2e7a975e5' };
    models[3] = { id: 'house4', name: 'house4', url: '../SampleData/house/house4.gltf', lon: 121.44, lat: 31.22, height: 0, pid: '4e027d42-f033-4bab-87f1-e34c8860b90e' };
    models[4] = { id: 'house5', name: 'house5', url: '../SampleData/house/house5.gltf', lon: 121.41, lat: 31.21, height: 0, pid: '918dcfaa-4568-4468-ba03-e379deaa99b7' };
    models[5] = { id: 'house6', name: 'house6', url: '../SampleData/house/house6.gltf', lon: 121.42, lat: 31.20, height: 0, pid: '2071736b-0054-4041-ad34-34f2e7a975e5' };
    models[6] = { id: 'house7', name: 'house7', url: '../SampleData/house/house7.gltf', lon: 121.43, lat: 31.22, height: 0, pid: '4e027d42-f033-4bab-87f1-e34c8860b90e' };
    models[7] = { id: 'house8', name: 'house8', url: '../SampleData/house/house8.gltf', lon: 121.44, lat: 31.21, height: 0, pid: '918dcfaa-4568-4468-ba03-e379deaa99b7' };
    models[8] = { id: 'house9', name: 'house9', url: '../SampleData/house/house9.gltf', lon: 121.45, lat: 31.20, height: 0, pid: '2071736b-0054-4041-ad34-34f2e7a975e5' };
    models[9] = { id: 'house10', name: 'house10', url: '../SampleData/house/house10.gltf', lon: 121.46, lat: 31.21, height: 0, pid: '918dcfaa-4568-4468-ba03-e379deaa99b7' };
    models[10] = { id: 'house11', name: 'house11', url: '../SampleData/house/house11.gltf', lon: 121.40, lat: 31.20, height: 0, pid: '4e027d42-f033-4bab-87f1-e34c8860b90e' };
    models[11] = { id: 'villa', name: 'villa', url: '../SampleData/house3/house3.gltf', lon: 121.45, lat: 31.22, height: 0, pid: '2071736b-0054-4041-ad34-34f2e7a975e5' };

    var loadedModels = [];

    var shapes = new Array();
    shapes[0] = { layer: '测试层', author: 'liu', date: '2017-06-18', ploy: [
        { name: 'A区', type: 'ploy', points: [] }
    ]};

    var tempPoints = [];
    var tempEntities = [];
    var tempPinEntities = [];
    var tempPinLon, tempPinLat;

    var handler = null;

    $(function() {

        /**初始化**/
        $("input[name='optionsRadios']").click(function() {
            if ($("input[name='optionsRadios']:eq(1)").prop("checked")) {
                //viewer.imageryLayers.addImageryProvider(vecLayer);
                vecLayer = viewer.imageryLayers.addImageryProvider(new Cesium.WebMapTileServiceImageryProvider({
                    url: "http://t0.tianditu.com/vec_w/wmts?service=wmts&request=GetTile&version=1.0.0&LAYER=vec&tileMatrixSet=w&TileMatrix={TileMatrix}&TileRow={TileRow}&TileCol={TileCol}&style=default&format=tiles",
                    layer: "tdtVecBasicLayer",
                    style: "default",
                    format: "image/jpeg",
                    tileMatrixSetID: "GoogleMapsCompatible",
                    show: false
                }));
            } else if ($("input[name='optionsRadios']:eq(0)").prop("checked")) {
                if (viewer.imageryLayers.contains(vecLayer)) {
                    viewer.imageryLayers.remove(vecLayer);
                }
            }
        });
        //标记层
        $("#cbxPinLayer").change(function() {
            if ($("#cbxPinLayer").prop("checked")) {
                for (var i = 0; i < tempPinEntities.length; i++) {
                    viewer.entities.add(tempPinEntities[i]);
                }

            } else {
                for (var i = 0; i < tempPinEntities.length; i ++) {
                    viewer.entities.remove(tempPinEntities[i]);
                }
            }
        });
        $("#pinColor").change(function() {
            $(this).css("background-color", $(this).val());
        });

        $("#cbxRoad").click(function() {
            if ($(this).prop("checked")) {
                roadLayer = viewer.imageryLayers.addImageryProvider(new Cesium.WebMapTileServiceImageryProvider({
                    url: "http://t0.tianditu.com/cia_w/wmts?service=wmts&request=GetTile&version=1.0.0&LAYER=cia&tileMatrixSet=w&TileMatrix={TileMatrix}&TileRow={TileRow}&TileCol={TileCol}&style=default&format=tiles",
                    layer: "tdtImgAnnoLayer",
                    style: "default",
                    format: "image/jpeg",
                    tileMatrixSetID: "GoogleMapsCompatible",
                    show: false
                }));
            } else {
                viewer.imageryLayers.remove(roadLayer);
            }
        });
        $("#cbxTestArc").click(function() {
            if ($(this).prop("checked")) {
                electricLayers = viewer.imageryLayers.addImageryProvider(new Cesium.ArcGisMapServerImageryProvider({
                    url: 'https://nationalmap.gov.au/proxy/http://services.ga.gov.au/site_3/rest/services/Electricity_Infrastructure/MapServer'
                }));
                viewer.camera.flyTo({
                    destination: Cesium.Rectangle.fromDegrees(114.591, -45.837, 148.970, -5.730)
                });
            } else {
                viewer.imageryLayers.remove(electricLayers);
            }
        });
        $("#opts .btn").click(function () {
            window.setTimeout(function() {
                if ($("input[name='opt']:eq(0)").prop("checked")) {
                    clearEffects();
                    setTips("");
                }
                else if ($("input[name='opt']:eq(1)").prop("checked")) {
                    clearEffects();
                    SetMode("addPin");
                    setTips("首先在地图上点击需要加点的位置，然后在弹出框内选取颜色，设置提示文字和显示内容，点击保存");
                }
                else if ($("input[name='opt']:eq(2)").prop("checked")) {
                    tempPoints = [];
                    for (var i = 0; i < tempEntities.length; i++) {
                        viewer.entities.remove(tempEntities[i]);
                    }
                    for (var i = 0; i < loadedModels.length; i++) {
                        if (loadedModels[i].color == Cesium.Color.SPRINGGREEN) {
                            loadedModels[i].color = {red:1,green:1, blue:1, alpha:1};
                        }
                    }
                    clearEffects();
                    setTips("绘制的图形被清除，点选页面标记可以删除标记");
                    SetMode("erase");
                }
                else if ($("input[name='opt']:eq(3)").prop("checked")) {
                    clearEffects();
                    SetMode("drawLine");
                    setTips("在地图上分别点击，即可绘制多个线段，点右键结束绘制");
                }
                else if ($("input[name='opt']:eq(4)").prop("checked")) {
                    clearEffects();
                    SetMode("drawCircle");
                    setTips("第一次点击绘制圆心，第二次点击根据和圆心的位置绘制半径");
                }
                else if ($("input[name='opt']:eq(5)").prop("checked")) {
                    clearEffects();
                    SetMode("drawSquare");
                    setTips("第一、二次点击绘制长方形的一个边，再次点击根据点和边的距离绘制方形");
                }
                else if ($("input[name='opt']:eq(6)").prop("checked")) {
                    clearEffects();
                    SetMode("drawPloy");
                    setTips("如果需要绘制多边形，在地图上使用左键逐个点选地点，右击闭合多边形");
                }
                else if ($("input[name='opt']:eq(7)").prop("checked")) {
                    clearEffects();
                    SetMode("pickBuilding");
                    setTips("点选建筑查看详细的三维模型");
                }
            },100);
        });

        var homeView = {
            destination: new Cesium.Cartesian3(-2852877.756667368, 4655857.919027944, 3288673.682311567),
            orientation: {
                direction: new Cesium.Cartesian3(0.5437275903005284, -0.8386290220423197, -0.03258329225728158),
                up: new Cesium.Cartesian3(0.05520718287689969, -0.00299987805272847, 0.9984704140286108)
            },
            complete: function() { LoadModel(); },
        };
        
        setTimeout(
            function() {
                // scene.primitives.removeAll();
                //reset();
                viewer.camera.flyTo(homeView);
                
                //viewer.zoomTo(wyoming);
            }, 3000);

        //var modelMatrix = Cesium.Transforms.eastNorthUpToFixedFrame(
        //Cesium.Cartesian3.fromDegrees(121.49, 31.22, 0.0));
        //var model = scene.primitives.add(Cesium.Model.fromGltf({
        //    url: '../SampleData/house/house1.gltf',
        //    modelMatrix: modelMatrix,
        //    scale: 20.0,
        //    name: 'SampleHouse',
        //    color: getColor('Red', 1)
        //}));

        $("#poly-show").click(function () {
            LoadModel();
        });

        $("#poly-hide").click(function () {
            HideModel();
        });

        //alert(getEnumPropertyNames(model).join('\r'));

    });

    function LoadModel() {
        for (var i = 0; i < models.length; i++) {
            var hasLoaded = false;
            for (var j = 0; j < loadedModels.length; j ++) {
                if (models[i].id == loadedModels[j].id) {
                    hasLoaded = true;
                }
            }
            if (!hasLoaded) {
                var modelMatrix = Cesium.Transforms.eastNorthUpToFixedFrame(
                    Cesium.Cartesian3.fromDegrees(models[i].lon, models[i].lat, models[i].height));

                var model = scene.primitives.add(
                    Cesium.Model.fromGltf({
                        url: models[i].url,
                        modelMatrix: modelMatrix,
                        scale: 20.0,
                        name: models[i].name,
                        id: models[i].id
                    }));
                loadedModels.push(model);
            }
        }
        //var cartesian = viewer.camera.pickEllipsoid(loadedModels[0].modelMatrix, scene.globe.ellipsoid);
        //alert(getEnumPropertyNames(cartesian).join('\r'));
        
    }

    function HideModel() {
        for (var i = 0; i < loadedModels.length; i++) {
            scene.primitives.remove(loadedModels[i]);
        }
        loadedModels = [];
    }

    function setTips(message, close) {
        if ("" == message) {
            $("#message").fadeOut();
        } else {
            if (close != undefined && close == true) {
                $("#message").html(message).fadeOut();
            } else {
                $("#message").html(message).fadeIn();
            }
        }
    }

    function clearEffects() {
        if (handler != null) {
            handler.destroy();
        }
    }

    //设置各种操作模式
    function SetMode(mode) {
        if (mode == "drawPloy")
        {
            tempPoints = [];
            handler = new Cesium.ScreenSpaceEventHandler(scene.canvas);
            handler.setInputAction(function (click) {
                var cartesian = viewer.camera.pickEllipsoid(click.position, scene.globe.ellipsoid);
                if (cartesian) {
                    var cartographic = Cesium.Cartographic.fromCartesian(cartesian);
                    var longitudeString = Cesium.Math.toDegrees(cartographic.longitude);
                    var latitudeString = Cesium.Math.toDegrees(cartographic.latitude);
                    tempPoints.push({ lon: longitudeString, lat: latitudeString });
                    var tempLength = tempPoints.length;
                    drawPoint(tempPoints[tempPoints.length-1]);
                    if (tempLength > 1) {
                        drawLine(tempPoints[tempPoints.length - 2], tempPoints[tempPoints.length - 1], true);
                    }
                } 
            }, Cesium.ScreenSpaceEventType.LEFT_CLICK);

            handler.setInputAction(function (click) {
                var cartesian = viewer.camera.pickEllipsoid(click.position, scene.globe.ellipsoid);
                if (cartesian) {
                    var tempLength = tempPoints.length;
                    if (tempLength < 3) {
                        alert('请选择3个以上的点再执行闭合操作命令');
                    } else {
                        drawLine(tempPoints[0], tempPoints[tempPoints.length - 1], true);
                        drawPoly(tempPoints);
                        highLightAssetsInArea(tempPoints);
                        alert('多边形面积' + SphericalPolygonAreaMeters(tempPoints) + '平方米');
                        tempPoints = [];
                    }

                }
            }, Cesium.ScreenSpaceEventType.RIGHT_CLICK);
        }
        else if (mode == "pickBuilding")
        {
            handler = new Cesium.ScreenSpaceEventHandler(scene.canvas);
            handler.setInputAction(function(click) {
                var pick = scene.pick(click.position);
                if (Cesium.defined(pick) && Cesium.defined(pick.node) && Cesium.defined(pick.mesh)) {
                    for (var i = 0; i < models.length; i ++) {
                        if (models[i].id == pick.node._model.id) {
                            var modelName = models[i].name;
                            var modelId = models[i].id;
                            var modelBimId = models[i].pid;
                            highLigthModel(modelId);
                            viewer.camera.flyTo({
                                destination: Cesium.Cartesian3.fromDegrees(models[i].lon, parseFloat(models[i].lat) - 0.01, 2000.0),
                                orientation: {
                                    direction: new Cesium.Cartesian3(0.5437275903005284, -0.8386290220423197, -0.03258329225728158),
                                    up: new Cesium.Cartesian3(0.05520718287689969, -0.00299987805272847, 0.9984704140286108)
                                },
                                complete: function() {
                                    if (confirm("你选择的是" + modelName + "，是否查看详细模型？")) {
                                        LoadBim(modelBimId);
                                    }
                                    unHighLightModel(modelId);
                                },
                            });
                        }
                    }
                }
            }, Cesium.ScreenSpaceEventType.LEFT_CLICK);
        }
        else if ("addPin" == mode)
        {
            handler = new Cesium.ScreenSpaceEventHandler(scene.canvas);
            handler.setInputAction(function (click) {
                var cartesian = viewer.camera.pickEllipsoid(click.position, scene.globe.ellipsoid);
                if (cartesian) {
                    var cartographic = Cesium.Cartographic.fromCartesian(cartesian);
                    tempPinLon = Cesium.Math.toDegrees(cartographic.longitude);
                    tempPinLat = Cesium.Math.toDegrees(cartographic.latitude);
                    $('#addPinModal').modal('show');
                }
            }, Cesium.ScreenSpaceEventType.LEFT_CLICK);
        }
        else if ("erase" == mode)
        {
            handler = new Cesium.ScreenSpaceEventHandler(scene.canvas);
            handler.setInputAction(function (click) {
                var pick = scene.pick(click.position);
                if (Cesium.defined(pick) && Cesium.defined(pick.id) && Cesium.defined(pick.id._id)) {
                    for (var i = 0; i < models.length; i++) {
                        if ( pick.id != undefined && tempPinEntities[i].id == pick.id._id) {
                            removePoint(tempPinEntities[i]);
                            tempPinEntities.splice(i, 1);
                        }
                    }
                }
            }, Cesium.ScreenSpaceEventType.LEFT_CLICK);
        }
        else if ("drawLine" == mode)
        {
            tempPoints = [];
            handler = new Cesium.ScreenSpaceEventHandler(scene.canvas);
            handler.setInputAction(function (click) {
                var cartesian = viewer.camera.pickEllipsoid(click.position, scene.globe.ellipsoid);
                if (cartesian) {
                    var cartographic = Cesium.Cartographic.fromCartesian(cartesian);
                    var longitudeString = Cesium.Math.toDegrees(cartographic.longitude);
                    var latitudeString = Cesium.Math.toDegrees(cartographic.latitude);
                    tempPoints.push({ lon: longitudeString, lat: latitudeString });
                    var tempLength = tempPoints.length;
                    drawPoint(tempPoints[tempPoints.length - 1]);
                    if (tempLength > 1) {
                        drawLine(tempPoints[tempPoints.length - 2], tempPoints[tempPoints.length - 1], true);
                    }
                }
            }, Cesium.ScreenSpaceEventType.LEFT_CLICK);
            handler.setInputAction(function (click) {
                tempPoints = [];
            }, Cesium.ScreenSpaceEventType.RIGHT_CLICK);
        }
        else if ("drawCircle" == mode)
        {
            tempPoints = [];
            handler = new Cesium.ScreenSpaceEventHandler(scene.canvas);
            handler.setInputAction(function (click) {
                var cartesian = viewer.camera.pickEllipsoid(click.position, scene.globe.ellipsoid);
                if (cartesian) {
                    var cartographic = Cesium.Cartographic.fromCartesian(cartesian);
                    var longitudeString = Cesium.Math.toDegrees(cartographic.longitude);
                    var latitudeString = Cesium.Math.toDegrees(cartographic.latitude);
                    tempPoints.push({ lon: longitudeString, lat: latitudeString });
                    var tempLength = tempPoints.length;
                    if (tempLength == 1) {
                        drawPoint(tempPoints[0]);
                    }
                    else if (tempLength == 2) {
                        drawPoint(tempPoints[1]);
                        drawLine(tempPoints[0], tempPoints[1], true);
                        //算两点间距离
                        var distance = getFlatternDistance(tempPoints[0].lat, tempPoints[0].lon, tempPoints[1].lat, tempPoints[1].lon);

                        var entity =
                        viewer.
                        entities.add({
                            position: Cesium.Cartesian3.fromDegrees(tempPoints[0].lon, tempPoints[0].lat),
                            ellipse: {
                                semiMinorAxis: distance,
                                semiMajorAxis: distance,
                                height: 0,
                                material: Cesium.Color.fromRandom({ alpha: 0.8 })
                            }
                        });
                        tempEntities.push(entity);

                        //高亮圈内模型
                        for (var i = 0; i < loadedModels.length; i++) {
                            for (var j = 0; j < models.length; j++) {
                                if (loadedModels[i].id == models[j].id && getFlatternDistance(models[j].lat, models[j].lon, tempPoints[0].lat, tempPoints[0].lon) <= distance) {
                                    loadedModels[i].color = Cesium.Color.SPRINGGREEN;
                                }
                            }
                        }

                        //面积
                        setTimeout(function () { alert("面积是 " + Math.PI * distance * distance + "平方米") },500);

                        tempPoints = [];
                    }
                }
            }, Cesium.ScreenSpaceEventType.LEFT_CLICK);
        }
        else if ("drawSquare" == mode) {
            tempPoints = [];
            handler = new Cesium.ScreenSpaceEventHandler(scene.canvas);
            handler.setInputAction(function (click) {
                var cartesian = viewer.camera.pickEllipsoid(click.position, scene.globe.ellipsoid);
                if (cartesian) {
                    var cartographic = Cesium.Cartographic.fromCartesian(cartesian);
                    var longitudeString = Cesium.Math.toDegrees(cartographic.longitude);
                    var latitudeString = Cesium.Math.toDegrees(cartographic.latitude);
                    tempPoints.push({ lon: longitudeString, lat: latitudeString });
                    var tempLength = tempPoints.length;
                    if (tempLength == 1) {
                        drawPoint(tempPoints[0]);
                    }
                    else if (tempLength == 2) {
                        //算两点间距离
                        var distance = getFlatternDistance(tempPoints[0].lat, tempPoints[0].lon, tempPoints[1].lat, tempPoints[1].lon);

                        var entity =
                        viewer.
                        entities.add({
                            position: Cesium.Cartesian3.fromDegrees(tempPoints[0].lon, tempPoints[0].lat),
                            ellipse: {
                                semiMinorAxis: distance,
                                semiMajorAxis: distance,
                                height: 0,
                                material: Cesium.Color.fromRandom({ alpha: 0.8 })
                            }
                        });
                        tempEntities.push(entity);

                        //高亮圈内模型
                        for (var i = 0; i < loadedModels.length; i++) {
                            for (var j = 0; j < models.length; j++) {
                                if (loadedModels[i].id == models[j].id && getFlatternDistance(models[j].lat, models[j].lon, tempPoints[0].lat, tempPoints[0].lon) <= distance) {
                                    loadedModels[i].color = Cesium.Color.SPRINGGREEN;
                                }
                            }
                        }

                        tempPoints = [];
                    }
                }
            }, Cesium.ScreenSpaceEventType.LEFT_CLICK);
        }
    }

    function drawPoint(point) {
        var entity = 
        viewer.entities.add({
            position: Cesium.Cartesian3.fromDegrees(point.lon, point.lat),
            point: {
                pixelSize: 10,
                color: Cesium.Color.CHARTREUSE
            }
        });
        tempEntities.push(entity);
    }

    function removePoint(entity) {
        viewer.entities.remove(entity);
    }

    function drawLine(point1, point2, showDistance) {
        var entity =
        viewer.entities.add({
            polyline: {
                positions: [Cesium.Cartesian3.fromDegrees(point1.lon, point1.lat), Cesium.Cartesian3.fromDegrees(point2.lon, point2.lat)],
                width: 10.0,
                material: new Cesium.PolylineGlowMaterialProperty({
                    color: Cesium.Color.CHARTREUSE.withAlpha(.5)
                })
            }
        });
        tempEntities.push(entity);
        if (showDistance) {
            var w = Math.abs(point1.lon - point2.lon);
            var h = Math.abs(point1.lat - point2.lat);
            var offsetV = w >= h ? 0.0005 : 0;
            var offsetH = w < h ? 0.001 : 0;
            var distance = getFlatternDistance(point1.lat, point1.lon, point2.lat, point2.lon);
            entity =
                viewer.entities.add({
                    position: Cesium.Cartesian3.fromDegrees(((point1.lon + point2.lon) / 2) + offsetH,
                    ((point1.lat + point2.lat) / 2) + offsetV),
                    label: {
                        text: distance.toFixed(1) + 'm',
                        font: '22px Helvetica',
                        fillColor: Cesium.Color.WHITE
                    }
                });
            tempEntities.push(entity);
        }
    }

    function drawPoly(points) {
        var pArray = [];
        for (var i = 0; i < points.length; i ++) {
            pArray.push(points[i].lon);
            pArray.push(points[i].lat);
        }
        var entity =
        viewer.entities.add({
            polygon: {
                hierarchy: new Cesium.PolygonHierarchy(Cesium.Cartesian3.fromDegreesArray(pArray)),
                material: Cesium.Color.CHARTREUSE.withAlpha(.5)
            }
        });
        tempEntities.push(entity);
    }

    function getColor(colorName, alpha) {
        var color = Cesium.Color[colorName.toUpperCase()];
        return Cesium.Color.fromAlpha(color, parseFloat(alpha));
    }

    //判断点是否在多边形内
    function PointInPoly(point, polyPoints) {
        for (var c = false, i = -1, l = polyPoints.length, j = l - 1; ++i < l; j = i)
            ((polyPoints[i].lat <= point.lat && point.lat < polyPoints[j].lat) || (polyPoints[j].lat <= point.lat && point.lat < polyPoints[i].lat))
            && (point.lon < (polyPoints[j].lon - polyPoints[i].lon) * (point.lat - polyPoints[i].lat) / (polyPoints[j].lat - polyPoints[i].lat) + polyPoints[i].lon)
            && (c = !c);
        return c;
    }

    //选区内模型高亮
    function highLightAssetsInArea(points) {
        
        for (var i = 0; i < loadedModels.length; i++) {
            for (var j = 0; j < models.length; j ++) {
                if (loadedModels[i].id == models[j].id && PointInPoly(models[j], points)) {
                    loadedModels[i].color = Cesium.Color.SPRINGGREEN;
                }
            }
        }
    }

    //高亮模型
    function highLigthModel(modelId) {
        for (var i = 0; i < loadedModels.length; i ++) {
            if (loadedModels[i].id == modelId) {
                loadedModels[i].color = Cesium.Color.SPRINGGREEN;
            }
        }
    }

    //取消高亮模型
    function unHighLightModel(modelId) {
        for (var i = 0; i < loadedModels.length; i++) {
            if (loadedModels[i].id == modelId) {
                loadedModels[i].color = {
                    red: 1,
                    green: 1,
                    blue: 1,
                    alpha: 1
                };
            }
        }
    }

    //定位
    function goLocation() {
        $('#flyToModal').modal('hide');
        $('#flyToModal').on('hidden.bs.modal', function(e) {
            viewer.camera.flyTo({
                destination: Cesium.Cartesian3.fromDegrees($("#jumpLon").val(), $("#jumpLat").val(), 1000.0)
            });
        });
    }

    //加点
    function addPin() {
        $('#addPinModal').modal('hide');
        var pin = viewer.entities.add({
            name: $("#pinContent").val(),
            position: Cesium.Cartesian3.fromDegrees(tempPinLon, tempPinLat),
            billboard: {
                image: $("#pinLabel").val() == "" ? pinBuilder.fromColor(Cesium.Color[$("#pinColor").val().toUpperCase()], 48).toDataURL() :
            pinBuilder.fromText($("#pinLabel").val(), Cesium.Color[$("#pinColor").val().toUpperCase()], 64).toDataURL(),
                verticalOrigin: Cesium.VerticalOrigin.BOTTOM
            }
        });
        tempPinEntities.push(pin);
        $("#pinLabel").val("");
        $("#pinContent").val("");
    }

    //计算两点间距离
    function getFlatternDistance(lat1, lng1, lat2, lng2) {
        var EARTH_RADIUS = 6378137.0;    //单位M
        var PI = Math.PI;

        function getRad(d) {
            return d * PI / 180.0;
        }
        var f = getRad((lat1 + lat2) / 2);
        var g = getRad((lat1 - lat2) / 2);
        var l = getRad((lng1 - lng2) / 2);

        var sg = Math.sin(g);
        var sl = Math.sin(l);
        var sf = Math.sin(f);

        var s, c, w, r, d, h1, h2;
        var a = EARTH_RADIUS;
        var fl = 1 / 298.257;

        sg = sg * sg;
        sl = sl * sl;
        sf = sf * sf;

        s = sg * (1 - sl) + (1 - sf) * sl;
        c = (1 - sg) * (1 - sl) + sf * sl;

        w = Math.atan(Math.sqrt(s / c));
        r = Math.sqrt(s * c) / w;
        d = 2 * w * a;
        h1 = (3 * r - 1) / 2 / c;
        h2 = (3 * r + 1) / 2 / s;

        return d * (1 + fl * (h1 * sf * (1 - sg) - h2 * (1 - sf) * sg));
    }

    //计算多边形面积
    var earthRadiusMeters = 6371000.0;
    var metersPerDegree = 2.0 * Math.PI * earthRadiusMeters / 360.0;
    var radiansPerDegree = Math.PI / 180.0;
    var degreesPerRadian = 180.0 / Math.PI;
    var pointArr;
    function SphericalPolygonAreaMeters(points) {
        var totalAngle = 0;
        for (var i = 0; i < points.length; i++) {
            var j = (i + 1) % points.length;
            var k = (i + 2) % points.length;
            totalAngle += Angle(points[i], points[j], points[k]);
        }
        var planarTotalAngle = (points.length - 2) * 180.0;
        var sphericalExcess = totalAngle - planarTotalAngle;
        if (sphericalExcess > 420.0) {
            totalAngle = points.length * 360.0 - totalAngle;
            sphericalExcess = totalAngle - planarTotalAngle;
        } else if (sphericalExcess > 300.0 && sphericalExcess < 420.0) {
            sphericalExcess = Math.abs(360.0 - sphericalExcess);
        }
        return sphericalExcess * radiansPerDegree * earthRadiusMeters * earthRadiusMeters;
    }

    /*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;
        return angle;
    }

    function LoadBim(projId) {
        //加载模型
        $('#myTabs li:eq(1) a').tab('show');
        
    }