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Convert PointCloud2ConstPtr to PointCloud2

asked 2019-07-02 04:37:37 -0600

A_YIng gravatar image

updated 2019-07-02 04:37:58 -0600


I would like to know how to convert convert PointCloud2ConstPtr to PointCloud2. I use these code:

  sensor_msgs::PointCloud2ConstPtr kinect_pointcloud_ptr;
  kinect_pointcloud_ptr = ros::topic::waitForMessage<sensor_msgs::PointCloud2> ("/voxel_output", ros::Duration (5.0));
  std::cerr << "Pointcloud points number: "<< kinect_pointcloud_ptr->width * kinect_pointcloud_ptr->height <<"";

  sensor_msgs::PointCloud2ConstPtr p_pointcloud_ptr;
  tf2_ros::Buffer tfBuffer;
  tf2_ros::TransformListener tfListener(tfBuffer);
  geometry_msgs::TransformStamped p_frame_to_kinect2_link;      
  p_frame_to_kinect2_link = tfBuffer.lookupTransform("kinect2_link", "p_frame", ros::Time::now(), ros::Duration(3.0));
  tf2::doTransform(kinect_pointcloud_ptr, p_pointcloud_ptr, p_frame_to_kinect2_link);

And I get some error:

Undefined reference to 「void tf2::doTransform<boost::shared_ptr<sensor_msgs::PointCloud2_<std::allocator<void> > const> >(boost::shared_ptr<sensor_msgs::PointCloud2_<std::allocator<void> > const> const&, boost::shared_ptr<sensor_msgs::PointCloud2_<std::allocator<void> > const>&, geometry_msgs::TransformStamped_<std::allocator<void> > const&)」

If anyone has good solution to suggest me. It will be nice. Thank!

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1 Answer

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answered 2019-07-02 06:05:02 -0600

You'll need to use the pcl_ros::transformPointCloud to transform a point cloud, as far as I know it cannot be done using the doTransform method.

You'll also need to make a non const point cloud to store the result. Whenever you see a const type in C++ it means that its value cannot be changed. So you'll need to define a variable like sensor_msgs::PointCloud2 p_output_pointcloud_ptr; for the result.

Hope this helps.

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Thank for your reply, it works for me. Here is my example code to provide to someone have the same question!

sensor_msgs::PointCloud2 pc;
sensor_msgs::PointCloud2 t_pc; 
pc = *(ros::topic::waitForMessage<sensor_msgs::PointCloud2>("/Topic_name",ros::Duration(3.0)));
pc.header.frame_id = "Source_frame";
pcl_ros::transformPointCloud("Target_frame", pc, t_pc, *tf_listener);
A_YIng gravatar image A_YIng  ( 2019-07-02 09:08:12 -0600 )edit

Great, glad you got it working.

PeteBlackerThe3rd gravatar image PeteBlackerThe3rd  ( 2019-07-02 10:41:09 -0600 )edit

But why would you need to use pcl_ros::transformPointCloud if there are no PCL types involved? That seems to make no sense. Why wouldn't you use the transform method of the tf2_ros::Buffer object?

alexe gravatar image alexe  ( 2020-03-27 19:25:24 -0600 )edit

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Asked: 2019-07-02 04:37:37 -0600

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Last updated: Jul 02 '19