pcl读取点云txt并获得 第4个值

答：您可以使用PCL库的方法从txt文件中读取点云数据，然后使用points数组来获取第四个值。以下是示例代码：

#include <iostream>
#include <pcl/io/pcd_io.h>
#include <pcl/point_types.h>

int main()
{
  pcl::PointCloud<pcl::PointXYZ>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZ>);
  if (pcl::io::loadPCDFile<pcl::PointXYZ> ("path/to/pointcloud.txt", *cloud) == -1) //* load the file
  {
    PCL_ERROR ("Couldn't read file test_pcd.pcd \n");
    return (-1);
  }
  std::cout << "Loaded " << cloud->width * cloud->height << " data points from test_pcd.pcd with the following fields: " << std::endl;
  for (size_t i = 0; i < cloud->points.size (); ++i)
    std::cout << "    (" << cloud->points[i].x << ", "
                            << cloud->points[i].y << ", "
                            << cloud->points[i].z << ", "
                            << cloud->points[i].data[3] << ")" << std::endl; //accessing the fourth element of each point in the dataset
}

请将“path/to/pointcloud.txt”替换为您自己的点云文件路径。