Cesium入门-3-官方完整实例

实例核心代码

//资源访问令牌 Cesium token
Cesium.Ion.defaultAccessToken='eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJqdGkiOiI4MWI5NTY0Mi1iOGE3LTQ3ZTMtOGQ4OC03NThiN2VkZGI4NTYiLCJpZCI6NzY2Niwic2NvcGVzIjpbImFzbCIsImFzciIsImFzdyIsImdjIl0sImlhdCI6MTU1MDIyNTM5OX0.2Abc9p46PA9kJ3E-BaKMXiyb0rvgo7AFUR1nR78VF7c'

//创建Cesium 场景
var viewer=new Cesium.Viewer('cesiumContainer',{
    scene3DOnly:true,
    selectionIndicator:true,
    baseLayerPicker:true,
    timeline:true,//时间轴
    animation:true,//动画轴
});

//增加地图图片资源提供者（CesiumIon） Cesium官方
viewer.imageryLayers.remove(0);   //图片层级管理 移除默认的基础层级提供者
viewer.imageryLayers.addImageryProvider(new Cesium.IonImageryProvider({assetId:3954}));

//设置地形
viewer.terrainProvider=Cesium.createWorldTerrain({
    requestWaterMask:true,//水渲染需求
    requestVertexNormals:true//顶点法线渲染需求
});

viewer.scene.globe.depthTestAgainstTerrain=true;//深度显示（用于湖泊河流 水深对周围景观的影响）
viewer.scene.globe.enableLighting=true;//全局日照（受太阳，月亮的位置而影响光照信息）

//创建初始化摄像机视图
var initialPosition=new Cesium.Cartesian3.fromDegrees(-73.998114468289017509, 40.674512895646692812, 2631.082799425431);//摄像机位置 ，经度，纬度，高度
var initialOrientation=new Cesium.HeadingPitchRoll.fromDegrees(7.1077496389876024807, -31.987223091598949054, 0.025883251314954971306);//飞行 专用的  表示旋转角度之类的东西： 飞行中飞机机体轴相对于地面的角位置
var homeCameraView={
    destination:initialPosition,
    orientation:{
        heading:initialOrientation.heading, //偏航角
        pitch:initialOrientation.pitch,     //俯仰角
        roll:initialOrientation.roll    //滚转角
    }
};
viewer.scene.camera.setView(homeCameraView);

//飞行时，相机的动画属性设置
homeCameraView.dutaion=2.0;
homeCameraView.maximumHeight=2000;
homeCameraView.pitchAdjustHeight=2000;
homeCameraView.endTransform=Cesium.Matrix4.IDENTITY;

// //覆盖初始相机视图
viewer.homeButton.viewModel.command.beforeExecute.addEventListener(function(e){
    e.canvel=true;
    viewer.scene.camera.flyTo(homeCameraView)   //貌似没效果 -.-
})

//设置时间轴
viewer.clock.shouldAnimate=true;//右下角圆盘指针控制的时钟动画
viewer.clock.startTime = Cesium.JulianDate.fromIso8601("2017-07-11T16:00:00Z"); //开始时间 使用iso8601国际标准
viewer.clock.stopTime = Cesium.JulianDate.fromIso8601("2017-07-11T16:20:00Z");  //停止时间
viewer.clock.currentTime = Cesium.JulianDate.fromIso8601("2017-07-11T16:00:00Z");//当前时间
viewer.clock.multiple=2; //时间流逝 速率
viewer.clock.clockStep=Cesium.ClockStep.SYSTEM_CLOCK_MULTIPLIER;//时钟的 步长
viewer.clock.clockRange=Cesium.ClockRange.LOOP_STOP;//循环
viewer.timeline.zoomTo(viewer.clock.startTime,viewer.clock.stopTime);//设置时间轴可见趋近

/**加载KML数据--添加地理标记  从KML文件中获取数据 由Cesium.KmlDataSource数据加载器加载--**/
var kmlOptions = {
    camera : viewer.scene.camera,
    canvas : viewer.scene.canvas,
    clampToGround : true
};
// 从KML 文件中加载地理标记点 geocache
//KML全称：Keyhole Markup Language，是基于XML（eXtensible Markup Language,可扩展标记语言）语法标准的一种标记语言（markup language）,由Google（谷歌）旗下的Keyhole公司发展并维护，用来表达地理标记
var geocachePromise = Cesium.KmlDataSource.load('https://gist.githubusercontent.com/rahwang/bf8aa3a46da5197a4c3445c5f5309613/raw/04e17770dd552fd2694e2597986fd480b18b5014/sampleGeocacheLocations.kml', kmlOptions);

// 从geocachePromise中解析标记点 并转化为  Cesium中的 实体对象（entity)
geocachePromise.then(function(dataSource) {
    //数据源添加到实际场景viewer 中的dataSources数据源中
    viewer.dataSources.add(dataSource);

    // Get the array of entities
    var geocacheEntities = dataSource.entities.values;

    for (var i = 0; i < geocacheEntities.length; i++) {
        var entity = geocacheEntities[i];
        if (Cesium.defined(entity.billboard)) {
            // Adjust the vertical origin so pins sit on terrain
            entity.billboard.verticalOrigin = Cesium.VerticalOrigin.BOTTOM;
            // Disable the labels to reduce clutter
            entity.label = "KML billboard 兴趣点"+i;
            // Add distance display condition  满足的距离条件时，显示兴趣点
            entity.billboard.distanceDisplayCondition = new Cesium.DistanceDisplayCondition(10.0, 20000.0);
            // Compute latitude and longitude in degrees 位置和角度
            var cartographicPosition = Cesium.Cartographic.fromCartesian(entity.position.getValue(Cesium.JulianDate.now()));
            //转化成经纬度
            var latitude = Cesium.Math.toDegrees(cartographicPosition.latitude);
            var longitude = Cesium.Math.toDegrees(cartographicPosition.longitude);
            // Modify description  兴趣点属性 描述
            var description = '<table class="cesium-infoBox-defaultTable cesium-infoBox-defaultTable-lighter"><tbody>';
            description += '<tr><th>' + "Latitude" + '</th><td>' + latitude + '</td></tr>';
            description += '<tr><th>' + "Longitude" + '</th><td>' + longitude + '</td></tr>';
            description += '</tbody></table>';
            entity.description = description;
        }
    }
});

/**加载GeoJson数据 ，添加邻近区图形  从GeoJson文件中获取数据 由GeoJsonDataSource数据加载器加载**/
var geojsonOptions = {
    clampToGround : true
};
// 从Geojson文件中获取 多边形 边界信息数据
var neighborhoodsPromise = Cesium.GeoJsonDataSource.load('https://gist.githubusercontent.com/rahwang/2c421916bb955ca722a4dbc8ab079c76/raw/ae8a1c5680fbd2fc6940dd3a8f941ad397bdc085/sampleNeighborhoods.geojson', geojsonOptions);

//从neighborhoodsPromise 数据源转化为Cesium中的数据实体entity
var neighborhoods;
neighborhoodsPromise.then(function(dataSource) {
    // 数据源添加到实际场景viewer 中的dataSources数据源中
    viewer.dataSources.add(dataSource);
    neighborhoods = dataSource.entities;

    // 获取总的数据实体 数组
    var neighborhoodEntities = dataSource.entities.values;
    for (var i = 0; i < neighborhoodEntities.length; i++) {
        var entity = neighborhoodEntities[i];

        if (Cesium.defined(entity.polygon)) {
            // Use kml neighborhood value as entity name
            entity.name = entity.properties.neighborhood;
            // 设置多边形 的材质 和透明
            entity.polygon.material = Cesium.Color.fromRandom({
                red : 0.1,
                maximumGreen : 0.5,
                minimumBlue : 0.5,
                alpha : 0.6
            });
            // Tells the polygon to color the terrain. ClassificationType.CESIUM_3D_TILE will color the 3D tileset, and ClassificationType.BOTH will color both the 3d tiles and terrain (BOTH is the default)
            entity.polygon.classificationType = Cesium.ClassificationType.TERRAIN;
            // 计算生成polygon的中心位置
            var polyPositions = entity.polygon.hierarchy.getValue(Cesium.JulianDate.now()).positions;
            var polyCenter = Cesium.BoundingSphere.fromPoints(polyPositions).center;
            polyCenter = Cesium.Ellipsoid.WGS84.scaleToGeodeticSurface(polyCenter);
            entity.position = polyCenter;
            // 实体标签 显示的信息设置
            entity.label = {
                text : entity.name,//文字
                showBackground : false,//背景
                scale : 0.6,//标签缩放大小
                horizontalOrigin : Cesium.HorizontalOrigin.CENTER,
                verticalOrigin : Cesium.VerticalOrigin.BOTTOM,
                distanceDisplayCondition : new Cesium.DistanceDisplayCondition(10.0, 8000.0),
                disableDepthTestDistance : Number.POSITIVE_INFINITY
            };
        }
    }
});

/**加载Czml数据 ，从czml文件中 由Cesium.CzmlDataSource 数据加载器加载飞行路径信息**/
// 从czml文件中加载数据
var dronePromise = Cesium.CzmlDataSource.load('https://gist.githubusercontent.com/rahwang/0d1afa6f9e5aa342cb699d26851d97df/raw/5fec1c0cebc097661579143096e796a097c9b629/sampleFlight.czml');
// Save a new drone model entity
var drone;
dronePromise.then(function(dataSource) {

    viewer.dataSources.add(dataSource);
    drone = dataSource.entities.values[0];
    // 加载一个gtlf格式的3D模型
    drone.model = {
        uri : 'https://gist.githubusercontent.com/rahwang/9843cb77fc1c6d07c287566ed4e08ee3/raw/dc3a9ff6fc73b784519ac9371c0e2cbd3ab3dc47/CesiumDrone.gltf',
        minimumPixelSize : 128,
        maximumScale : 2000
    };
    // 实时计算飞行时，模型的巡航角度
    drone.orientation = new Cesium.VelocityOrientationProperty(drone.position);

    // 圆滑路径，使路径相对平滑过渡 插值过渡
    drone.position.setInterpolationOptions({
        interpolationAlgorithm : Cesium.HermitePolynomialApproximation, //插值算法
        interpolationDegree : 2
    });
    //3D笛卡尔坐标点
    drone.viewFrom = new Cesium.Cartesian3(-30, 0, 0);
});

/**加载3dTile 数据集 瓦片数据  ，其实就是景观建筑群数据**/
var city = viewer.scene.primitives.add(new Cesium.Cesium3DTileset({ url: Cesium.IonResource.fromAssetId(3839) }));//我账号没有该地理资源。。。

// Adjust the tileset height so it's not floating above terrain
var heightOffset = -32;
city.readyPromise.then(function(tileset) {
    //3D瓦片的position 位置
    var boundingSphere = tileset.boundingSphere;
    var cartographic = Cesium.Cartographic.fromCartesian(boundingSphere.center);
    var surfacePosition = Cesium.Cartesian3.fromRadians(cartographic.longitude, cartographic.latitude, 0.0);
    var offsetPosition = Cesium.Cartesian3.fromRadians(cartographic.longitude, cartographic.latitude, heightOffset);
    var translation = Cesium.Cartesian3.subtract(offsetPosition, surfacePosition, new Cesium.Cartesian3());
    tileset.modelMatrix = Cesium.Matrix4.fromTranslation(translation);
});

//定义Tile样式
// Define a white, opaque building style
var defaultStyle = new Cesium.Cesium3DTileStyle({
    color : "color('white')",
    show : true
});

// Define a white, transparent building style
var transparentStyle = new Cesium.Cesium3DTileStyle({
    color : "color('white', 0.3)",
    show : true
});

// Define a style in which buildings are colored by height 针对不同高度给与不同的样式
var heightStyle = new Cesium.Cesium3DTileStyle({
    color : {
        conditions : [
            ["${height} >= 300", "rgba(45, 0, 75, 0.5)"],
            ["${height} >= 200", "rgb(102, 71, 151)"],
            ["${height} >= 100", "rgb(170, 162, 204)"],
            ["${height} >= 50", "rgb(224, 226, 238)"],
            ["${height} >= 25", "rgb(252, 230, 200)"],
            ["${height} >= 10", "rgb(248, 176, 87)"],
            ["${height} >= 5", "rgb(198, 106, 11)"],
            ["true", "rgb(127, 59, 8)"]
        ]
    }
});

// Set the tileset style to default 最终设置给tile的样式
city.style = defaultStyle;

//鼠标事件互动
var previousPickedEntity;
var handler=viewer.screenSpaceEventHandler;//在屏幕空间发生的事件柄
handler.setInputAction(function(movement){
    var pickedPrimitive=viewer.scene.pick(movement.endPosition);//拾取对象
    var pickedEntity=Cesium.defined(pickedPrimitive)?pickedPrimitive.id:undefined;
    //高亮挑选的实体对象
    if(Cesium.defined(previousPickedEntity)){
        previousPickedEntity.billboard.scale=1.0;
        previousPickedEntity.billboard.color=Cesium.Color.WHITE;
    }
    // //高亮当前拾取的Entity对象
    if (Cesium.defined(pickedEntity) && Cesium.defined(pickedEntity.billboard)) {
        pickedEntity.billboard.scale = 2.0;
        pickedEntity.billboard.color = Cesium.Color.ORANGERED;
        previousPickedEntity = pickedEntity;
    }

},Cesium.ScreenSpaceEventType.MOUSE_MOVE);//鼠标移动事件

//切换相机
var freeModeElement=document.getElementById('freeMode');//获取dom元素
var droneModeElement=document.getElementById('droneMode');
freeModeElement.addEventListener('change',setViewMode);
droneModeElement.addEventListener('change',setViewMode);
function setViewMode(){
    if(droneModeElement.checked){
        viewer.trackedEntity=drone//相机跟踪实体对象
    }else{
        viewer.trackedEntity=undefined;
        viewer.scene.camera.flyTo(homeCameraView);
    }
}

//用户双击实体是，会自动跟踪实体，可以添加一些处理Ui的逻辑
viewer.trackedEntityChanged.addEventListener(function(){
    if (viewer.trackedEntity === drone) {
        freeModeElement.checked = false;
        droneModeElement.checked = true;
    }
} )

//同理设置一些显示
var shadowsElement = document.getElementById('shadows');
var neighborhoodsElement =  document.getElementById('neighborhoods');
shadowsElement.addEventListener('change', function (e) {
    viewer.shadows = e.target.checked;//场景是否阴影
});

neighborhoodsElement.addEventListener('change', function (e) {
    neighborhoods.show = e.target.checked;//polygon 邻近区图形是否显示
});

//加载城市建筑群数据完成，关掉遮罩层，我账号无此资源，直接注释
// // Finally, wait for the initial city to be ready before removing the loading indicator.
// var loadingIndicator = document.getElementById('loadingIndicator');
// loadingIndicator.style.display = 'block';
// city.readyPromise.then(function () {
//     loadingIndicator.style.display = 'none';//
// });

重要知识点

创建场景

创建地形

• Cesium.CesiumTerrainProvider 地形提供者

 let viewer=new Cesium.Viewer('cesiumContainer',{//世界地形
          terrainProvider:new Cesium.CesiumTerrainProvider({
              url:Cesium.IonResource.fromAssetId(1),
              requestWaterMask:true,//水效果
              requestVertexNormals: true//顶点法线效果
          })
      })

添加图片层级（图片资源提供者xxxImageryProvider）

创建初始化摄像机视图

加载数据

• KML数据加载

    var geocachePromise = Cesium.KmlDataSource.load(“URL”）
  

• 加载GeoJson数据 ，添加邻近区图形

    var neighborhoodsPromise = Cesium.GeoJsonDataSource.load("URL")
  

• CZML数据加载

    var dronePromise = Cesium.CzmlDataSource.load("URL")
  

• 3DTile 瓦片数据加载 (景观，建筑群，)

    var city = viewer.scene.primitives.add(new Cesium.Cesium3DTileset({ url: Cesium.IonResource.fromAssetId(3839) }));
  

3DTile样式定义

•   var defaultStyle = new Cesium.Cesium3DTileStyle({
          color : "color('white')",
          show : true
    });
  

• // Define a style in which buildings are colored by height 针对不同高度给与不同的样式var heightStyle = new Cesium.Cesium3DTileStyle({
  color : {
      conditions : [
          ["${height} >= 300", "rgba(45, 0, 75, 0.5)"],
          ["${height} >= 200", "rgb(102, 71, 151)"],
          ["${height} >= 100", "rgb(170, 162, 204)"],
          ["${height} >= 50", "rgb(224, 226, 238)"],
          ["${height} >= 25", "rgb(252, 230, 200)"],
          ["${height} >= 10", "rgb(248, 176, 87)"],
          ["${height} >= 5", "rgb(198, 106, 11)"],
          ["true", "rgb(127, 59, 8)"]
      ]
  }});
  

•   // Set the tileset style to default 最终设置给tile的样式
    city.style = defaultStyle;
  

事件互动

• 获取事件柄

    var handler=viewer.screenSpaceEventHandler;//在屏幕空间发生的事件柄
  

• 事件处理
  

  handler.setInputAction(处理函数,具体事件)

        handler.setInputAction(function(movement){
    var pickedPrimitive=viewer.scene.pick(movement.endPosition);//拾取对象
    var pickedEntity=Cesium.defined(pickedPrimitive)?pickedPrimitive.id:undefined;
    //高亮挑选的实体对象
    if(Cesium.defined(previousPickedEntity)){
        previousPickedEntity.billboard.scale=1.0;
        previousPickedEntity.billboard.color=Cesium.Color.WHITE;
    }
    // //高亮当前拾取的Entity对象
    if (Cesium.defined(pickedEntity) && Cesium.defined(pickedEntity.billboard)) {
        pickedEntity.billboard.scale = 2.0;
        pickedEntity.billboard.color = Cesium.Color.ORANGERED;
        previousPickedEntity = pickedEntity;
    }

},Cesium.ScreenSpaceEventType.MOUSE_MOVE);//鼠标移动事件

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最后编辑时间为: 2019/02/20 20:19