cesium实现底图和地形动态切换及supermap三维服务加载（官网demo）

//*******加载三维城市模型**********//
function show3dCity(){
//加载高精度三维模型
var scene = viewer.scene;
var widget = viewer.cesiumWidget;
//加载倾斜摄影测量数据
try{
//添加S3M图层服务
var promise = scene.addS3MTilesLayerByScp('https://www.supermapol.com/realspace/services/3D-jinjiang/rest/realspace/datas/jinjiang/config', { name :'sl'});
Cesium.when(promise,function(layer){
//设置相机视角
scene.camera.setView({
destination : new Cesium.Cartesian3.fromDegrees(118.5486,24.8027,80),
orientation : {
heading : 5.295661577745349,
pitch : -0.18831704619320822,
roll : 0
}
});
},function(e){
if (widget._showRenderLoopErrors) {
var title = '渲染时发生错误，已停止渲染。';
widget.showErrorPanel(title, undefined, e);
}
}).then(function(){
//加载kml文件
viewer.dataSources.add(Cesium.KmlDataSource.load('./SampleData/kml/model.kml',{
camera : scene.camera,
canvas : scene.canvas