Cesium设置地球球体和图层透明度

• 设置球体透明度

  viewer.scene.globe.baseColor = new Cesium.Color(0.0, 0.0, 0.0, 0.0);
  viewer.scene.globe.translucency.enabled = true;
  viewer.scene.globe.undergroundColor = undefined;
  //去除地球周围白线
  viewer.scene.skyAtmosphere.show = false;

• 设置图层透明度

var _layers = viewer.imageryLayers._layers;
for (let i = 0, len = _layers.length; i < len; i++) {
    //图层透明度
    _layers[i].alpha = 0.2;
}