Cesium 基于MapBox底图加载3DTiles 模型

3DTiles 模型采用   CATIA V5 R22 --->3dxml --->GLB--->B3DM

var extent = Cesium.Rectangle.fromDegrees(75, 60.808406, 135.313421, 10);
Cesium.Camera.DEFAULT_VIEW_RECTANGLE = extent;
Cesium.Camera.DEFAULT_VIEW_FACTOR = 0;
Cesium.Ion.defaultAccessToken = "你的Token";
Cesium.CreditDisplay.cesiumCredit = "测试";
var viewer = new Cesium.Viewer('cesiumContainer', {
    animation: false,//是否创建动画小器件，左下角仪表
    baseLayerPicker: false,//是否显示图层选择器
    fullscreenButton: true,//是否显示全屏按钮
    geocoder: true,//是否显示geocoder小器件，右上角查询按钮
    homeButton: true,//是否显示Home按钮
    infoBox: false,//是否显示信息框
    sceneModePicker: true,//是否显示3D/2D选择器
    selectionIndicator: false,//是否显示选取指示器组件
    timeline: false,//是否显示时间轴
    navigationHelpButton: false,//是否显示右上角的帮助按钮
    scene3DOnly: true,//如果设置为true，则所有几何图形以3D模式绘制以节约GPU资源
    clock: new Cesium.Clock(),//用于控制当前时间的时钟对象
    selectedImageryProviderViewModel: undefined,//当前图像图层的显示模型，仅baseLayerPicker设为true有意义
    //imageryProviderViewModels: Cesium.createDefaultImageryProviderViewModels(),//可供BaseLayerPicker选择的图像图层ProviderViewModel数组
    selectedTerrainProviderViewModel: undefined,//当前地形图层的显示模型，仅baseLayerPicker设为true有意义
    terrainProviderViewModels: Cesium.createDefaultTerrainProviderViewModels(),//可供BaseLayerPicker选择的地形图层ProviderViewModel数组
    skyBox: new Cesium.SkyBox({
        sources: {
            positiveX: '/Build/Cesium/Assets/Textures/SkyBox/tycho2t3_80_px.jpg',
            negativeX: '/Build/Cesium/Assets/Textures/SkyBox/tycho2t3_80_mx.jpg',
            positiveY: '/Build/Cesium/Assets/Textures/SkyBox/tycho2t3_80_py.jpg',
            negativeY: '/Build/Cesium/Assets/Textures/SkyBox/tycho2t3_80_my.jpg',
            positiveZ: '/Build/Cesium/Assets/Textures/SkyBox/tycho2t3_80_pz.jpg',
            negativeZ: '/Build/Cesium/Assets/Textures/SkyBox/tycho2t3_80_mz.jpg'
        }
    }),//用于渲染星空的SkyBox对象
    fullscreenElement: document.body,//全屏时渲染的HTML元素,
    useDefaultRenderLoop: true,//如果需要控制渲染循环，则设为true
    targetFrameRate: undefined,//使用默认render loop时的帧率
    showRenderLoopErrors: false,//如果设为true，将在一个HTML面板中显示错误信息
    automaticallyTrackDataSourceClocks: true,//自动追踪最近添加的数据源的时钟设置
    contextOptions: undefined,//传递给Scene对象的上下文参数（scene.options）
    sceneMode: Cesium.SceneMode.SCENE3D //初始场景模式
});

var mapbox = new Cesium.MapboxImageryProvider({
    mapId: 'mapbox.satellite',
    accessToken: '你的Token'
});
viewer.imageryLayers.addImageryProvider(mapbox);

var tileset = viewer.scene.primitives.add(new Cesium.Cesium3DTileset({ url: '/files/test/tileset.json' }));
viewer.scene.primitives.add(tileset);

tileset.readyPromise.then(function (tileset) {
    viewer.scene.primitives.add(tileset);
    viewer.zoomTo(tileset, new Cesium.HeadingPitchRange(0.5, -0.2, tileset.boundingSphere.radius * 1.0));
}).otherwise(function (error) {
    console.log(error);
});

Cesium.CreditDisplay.cesiumCredit = null;
// 创建DIV标签
var bubbleDiv = document.createElement('div');
viewer.container.appendChild(bubbleDiv);
bubbleDiv.className = 'bubble';
bubbleDiv.style.display = 'none';
bubbleDiv.style.position = 'absolute';
bubbleDiv.style.bottom = '0';
bubbleDiv.style.left = '0';
bubbleDiv.style['pointer-events'] = 'none';
bubbleDiv.style.padding = '4px';
bubbleDiv.style.zIndex = 100;

// 有关当前选定功能的信息
var selected = {
    feature: undefined,
    originalColor: new Cesium.Color()
};
var selectedEntity = new Cesium.Entity();
// 获取默认的鼠标左键处理程序
var clickHandler = viewer.screenSpaceEventHandler.getInputAction(Cesium.ScreenSpaceEventType.LEFT_CLICK);
// 如果不支持轮廓，请在鼠标悬停时将特征颜色更改为黄色，在单击鼠标时将特征颜色更改为绿色。
if (Cesium.PostProcessStageLibrary.isSilhouetteSupported(viewer.scene)) {
    //支持剪影
    var silhouetteBlue = Cesium.PostProcessStageLibrary.createEdgeDetectionStage();
    silhouetteBlue.uniforms.color = Cesium.Color.BLUE;
    silhouetteBlue.uniforms.length = 0.01;
    silhouetteBlue.selected = [];

    var silhouetteGreen = Cesium.PostProcessStageLibrary.createEdgeDetectionStage();
    silhouetteGreen.uniforms.color = Cesium.Color.LIME;
    silhouetteGreen.uniforms.length = 0.01;
    silhouetteGreen.selected = [];

    viewer.scene.postProcessStages.add(Cesium.PostProcessStageLibrary.createSilhouetteStage([silhouetteBlue, silhouetteGreen]));

          viewer.screenSpaceEventHandler.setInputAction(function onLeftClick(movement) {
            // 如果先前选择了功能，请撤消突出显示
            silhouetteGreen.selected = [];

            // P选择一个新功能
            var pickedFeature = viewer.scene.pick(movement.position);
            if (!Cesium.defined(pickedFeature)) {
                clickHandler(movement);
                return;
            }

            //选择功能（如果尚未选择）
            if (silhouetteGreen.selected[0] === pickedFeature) {
                return;
            }
            // 保存所选功能的原始颜色
            var highlightedFeature = silhouetteBlue.selected[0];
            if (pickedFeature === highlightedFeature) {
                silhouetteBlue.selected = [];
            }
            //突出显示新选择的功能
            silhouetteGreen.selected = [pickedFeature];
        }, Cesium.ScreenSpaceEventType.LEFT_CLICK);
 var highlighted = {
        feature: undefined,
        originalColor: new Cesium.Color()
    };

    //将特征悬停上色为黄色。
    viewer.screenSpaceEventHandler.setInputAction(function onMouseMove(movement) {
        //如果以前突出显示某个功能，请撤消突出显示
        if (Cesium.defined(highlighted.feature)) {
            highlighted.feature.color = highlighted.originalColor;
            highlighted.feature = undefined;
        }
        // 选择一个新功能
        var pickedFeature = viewer.scene.pick(movement.endPosition);
        if (!Cesium.defined(pickedFeature)) {
            bubbleDiv.style.display = 'none';
            return;
        }
        // 选择了某项功能，因此请显示其叠加内容
        bubbleDiv.style.display = 'block';
        bubbleDiv.style.bottom = viewer.canvas.clientHeight - movement.endPosition.y + 'px';
        bubbleDiv.style.left = movement.endPosition.x + 'px';
        var name = pickedFeature.getProperty('name');
        if (!Cesium.defined(name)) {
            name = pickedFeature.getProperty('id');
        }
        bubbleDiv.textContent = name;
        // 突出显示该功能（如果尚未选择）
        if (pickedFeature !== selected.feature) {
            highlighted.feature = pickedFeature;
            Cesium.Color.clone(pickedFeature.color, highlighted.originalColor);
            pickedFeature.color = Cesium.Color.YELLOW;
        }
    }, Cesium.ScreenSpaceEventType.MOUSE_MOVE);
}

结果发现Mapbox 地图加载也太慢了，不知道是我们单位的网不好，还是本身就慢。