// 初始化
    let viewer = new Cesium.Viewer("viewerContainer")

    // 分析参数
    var viewModel = { verticalAngle: 90, horizontalAngle: 120, distance: 10 };

    // 添加可视域
    var viewshed = new Cesium.ViewShed3D(viewer, {
        horizontalAngle: Number(viewModel.horizontalAngle),
        verticalAngle: Number(viewModel.verticalAngle),
        distance: Number(viewModel.distance),
        calback: function () {
          viewModel.distance = viewshed.distance
        }
    });

    // 清除可视域
    viewshed.destroy();