变量是：

std::vector<pcl::PointCloud<pcl::PointXYZRGB>::Ptr> clusters_k_upper
std::vector<pcl::PointCloud<pcl::PointXYZRGB>::Ptr> clusters_k_lower
std::vector<pcl::PointCloud<pcl::PointXYZRGB>::Ptr> clusters_underk_upper
std::vector<pcl::PointCloud<pcl::PointXYZRGB>::Ptr>> clusters_underk_lower

# 变量填充

1. 直接使用（非函数）

// 创建一个 PCLVisualizer 对象
                pcl::visualization::PCLVisualizer viewer("Point Cloud Visualization");
                for (size_t i = 0; i < clusters_k_upper.size(); ++i) {
                    // 创建不同的颜色处理器
                    pcl::visualization::PointCloudColorHandlerCustom<pcl::PointXYZRGB> color_handler_k_upper(clusters_k_upper[i], 255, 0, 0); // 红色
                    pcl::visualization::PointCloudColorHandlerCustom<pcl::PointXYZRGB> color_handler_k_lower(clusters_k_lower[i], 0, 255, 0); // 绿色
                    pcl::visualization::PointCloudColorHandlerCustom<pcl::PointXYZRGB> color_handler_underk_upper(clusters_underk_upper[i], 0, 0, 255); // 蓝色
                    pcl::visualization::PointCloudColorHandlerCustom<pcl::PointXYZRGB> color_handler_underk_lower(clusters_underk_lower[i], 255, 255, 0); // 黄色

                    // 为每个点云生成唯一的ID
                    std::string id_k_upper = "upper k " + std::to_string(i);
                    std::string id_k_lower = "lower k " + std::to_string(i);
                    std::string id_underk_upper = "upper underk " + std::to_string(i);
                    std::string id_underk_lower = "lower underk " + std::to_string(i);

                    // 添加点云到可视化对象
                    viewer.addPointCloud<pcl::PointXYZRGB>(clusters_k_upper[i], color_handler_k_upper, id_k_upper);
                    viewer.addPointCloud<pcl::PointXYZRGB>(clusters_k_lower[i], color_handler_k_lower, id_k_lower);
                    viewer.addPointCloud<pcl::PointXYZRGB>(clusters_underk_upper[i], color_handler_underk_upper, id_underk_upper);
                    viewer.addPointCloud<pcl::PointXYZRGB>(clusters_underk_lower[i], color_handler_underk_lower, id_underk_lower);

                    // 可以选择设置点大小
                    viewer.setPointCloudRenderingProperties(pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 1, id_k_upper);
                    viewer.setPointCloudRenderingProperties(pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 1, id_k_lower);
                    viewer.setPointCloudRenderingProperties(pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 1, id_underk_upper);
                    viewer.setPointCloudRenderingProperties(pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 1, id_underk_lower);
                }

// 设置视窗的背景颜色
                viewer.setBackgroundColor(0, 0, 0);

// 循环直到视窗关闭
                while (!viewer.wasStopped()) {
                    viewer.spinOnce();
                }