var cUtil = {
  cartesianToLnglat:(cartesian)=>{
    //  //笛卡尔空间坐标转WGS84弧度.
    //  const ellipsoid84 = Cesium.Ellipsoid.wgs84;
    //  const cartographicPosition = ellipsoid84.cartesianToCartographic(cartesian);
    const cartographicPosition = Cesium.Cartographic.fromCartesian(cartesian);

    return [
      Cesium.Math.toDegrees(cartographicPosition.longitude),
      Cesium.Math.toDegrees(cartographicPosition.latitude),
    ]
  }
}