一、创建地图时添加

     let imageryLayer2 = Cesium.ImageryLayer.fromProviderAsync(new Cesium.UrlTemplateImageryProvider({url:"data/Assets/Textures/NaturalEarthII" + "/{z}/{x}/{reverseY}.jpg",tilingScheme: new Cesium.GeographicTilingScheme(),maximumLevel: 5,}));let imageryLayer3 = Cesium.ImageryLayer.fromProviderAsync(new Cesium.UrlTemplateImageryProvider({url: "SameUrlPath/{z}/{x}/{y}.png",layer: "imgLayer",minimumLevel: 0,maximumLevel: 8,}));this.viewer = new Cesium.Viewer(this.$refs.cesiumContainer, {selectionIndicator: false,infoBox: false,contextOptions: {msaaLevel: 8, // 硬件反走样，默认值为 1requestWebgl2: true,//requestWebgl1: true,