how to get h*w point cloud from laser scan not just planer

asked 2017-07-29 08:05:22 -0600

I am trying to convert a laser scan into point cloud so i can use its cartesian cordintes for computer vision purpose. But when i do it it seems like the width of point cloud converted is only 1. Before this i was using kinect sensor where both height and width were not 1. i'm getting confused to use the hokuyo sensor/multisense sensor. I am using gazbo for getting the lidar scan data. To convert lidar scan into pointcloud2 data i'm using this program:

#include <ros/ros.h>

    #include <tf/transform_listener.h>
    #include <laser_geometry/laser_geometry.h>

    class My_Filter {
        void scanCallback(const sensor_msgs::LaserScan::ConstPtr& scan);
        ros::NodeHandle node_;
        laser_geometry::LaserProjection projector_;
        tf::TransformListener tfListener_;

        ros::Publisher point_cloud_publisher_;
        ros::Subscriber scan_sub_;

        scan_sub_ = node_.subscribe<sensor_msgs::LaserScan> ("/multisense/lidar_scan", 100, 

&My_Filter::scanCallback, this);
            point_cloud_publisher_ = node_.advertise<sensor_msgs::PointCloud2> ("/my_cloud", 100, false);
void My_Filter::scanCallback(const sensor_msgs::LaserScan::ConstPtr& scan){
    sensor_msgs::PointCloud2 cloud;
    projector_.transformLaserScanToPointCloud("/head", *scan, cloud, tfListener_);

int main(int argc, char** argv)
    ros::init(argc, argv, "my_filter");

    My_Filter filter;


    return 0;

Here when i run this node, the height of point cloud is fine but width is only 1. and when i visualize the laser scan or pointcloud or pointcloud2 in rviz even when the lidar is rotating i can only see 2-d points as shown in below screenshot. Why is this happening. what should i do to convert it into 3d point cloud? Here all the point lies in single plane. image description

I need the point data like from kinect sensor which will have height and weight, and where the points will be in cartesian form.

edit retag flag offensive close merge delete


as I remember, multisense uses hokuyo which produces planar laser scans so the output in rviz will be rotating point clouds on a plane. So it's the expected output. A couple of gazebo tutorials that show the expected output of multisense lidar_scan in rviz: 1) 2)

iche033 gravatar imageiche033 ( 2017-08-01 10:58:30 -0600 )edit

before this i was uaing kinect sensor so how can i use this data like before? that time i used to have height and weidth of poont cloud and each (x,y) used to represent a point in given point cloud. now how do i do this with this hokuyo sensor?

hari1234 gravatar imagehari1234 ( 2017-08-02 08:09:59 -0600 )edit