pcl 打印一个点的法线

可以使用pcl::Normal类来打印一个点的法线，具体代码如下：

pcl::PointCloud<pcl::PointXYZ>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZ>);
pcl::NormalEstimation<pcl::PointXYZ, pcl::Normal> ne;
pcl::PointCloud<pcl::Normal>::Ptr normals(new pcl::PointCloud<pcl::Normal>);
pcl::search::KdTree<pcl::PointXYZ>::Ptr tree(new pcl::search::KdTree<pcl::PointXYZ>);

// 填充点云数据
cloud->width = 5;
cloud->height = 1;
cloud->points.resize(cloud->width * cloud->height);
for (size_t i = 0; i < cloud->points.size(); ++i)
{
cloud->points[i].x = 1024 * rand() / (RAND_MAX + 1.0f);
cloud->points[i].y = 1024 * rand() / (RAND_MAX + 1.0f);
cloud->points[i].z = 1024 * rand() / (RAND_MAX + 1.0f);
}

// 估计法线
ne.setInputCloud(cloud);
ne.setSearchMethod(tree);
ne.setKSearch(20);
ne.compute(*normals);

// 打印第一个点的法线
std::cout << "Normal of the first point: " << normals->points[0].normal_x << " "
<< normals->points[0].normal_y << " "
<< normals->points[0].normal_z << std::endl;