Hector PointCloud Tools

Some simple packages for common pointcloud needs

hector_pointcloud_accumulator

Voxel-filtered pointcloud accumulator. You can choose if it should store a running average, the highest z or the point closest to the center for each voxel.

pointcloud_accumulator

Example:

ros2 launch hector_pointcloud_accumulator pointcloud_accumulator.launch.yaml resolution:=0.025 frame:=map publish_rate:=0.2 aggregation_mode:=average topics:=["pointcloud1","pointcloud2"] output_topic:=accumulated_pointcloud

Subscribed Topics

Topic	Type	Description
/pointcloud	sensor_msgs/msg/PointCloud2	Default input topic for pointclouds if parameter topics is not used.

Published Topics

Topic	Type	Description
/accumulated_pointcloud	sensor_msgs/msg/PointCloud2	Output topic for accumulated pointcloud

Services

Service	Type	Description
/enable_pointcloud	std_srvs/srv/SetBool	Turn pointcloud processing on or off
/reset_pointcloud	std_srvs/srv/Trigger	Clear all accumulated data

Parameters

Parameter	Type	Default	Description
resolution	double	0.025	Resolution of the voxel filter
frame	string	"map"	The frame into which all pointclouds are accumulated
publish_rate	double	0.2	Frequency at which the node publishes on /cloud_out
aggregation_mode	string	"average"	Controls how points within the same voxel are integrated. Allowed values are: "average", "highest_z", "closest_to_center"
topics	string_array	["pointcloud"]	The topics names of all topics that should be accumulated together
output_topic	string	"accumulated_pointcloud"	The topic name of the accumulated pointcloud

hector_pointcloud_io

Executables to load and publish a pointcloud from a file, and to save a pointcloud from a given topic to a file. Includes the service server node pointcloud_saver that can save pointclouds from a topic on service call.

Supported formats: ifs, pcd, ply, vtk

load_pointcloud

Continuously publishes the selected pointcloud on the selected topic.

Example:

ros2 run hector_pointcloud_io load_pointcloud /pointcloud_topic path_to_file.pcd

save_pointcloud

Stores the first pointcloud received on the selected topic.

Example:

ros2 run hector_pointcloud_io save_pointcloud /pointcloud_topic path_to_file.ply

pointcloud_saver

Subscribed Topics

Topic	Type	Description
<topic>	sensor_msgs/msg/PointCloud2	The topic from where pointclouds are saved

Services

Service	Type	Description
~/save_pointcloud	std_srvs/srv/Trigger	Saves the first pointcloud received on <topic> within <timeout_ms> milliseconds after the service call

Parameters

Parameter	Type	Description
topic	string	Topic to listen for pointclouds on
ouput_folder	string	Folder to save pointclouds to
output_format	string	Output format of pointclouds. Supported: pcd, ifs, ply, vtk
output_filename_prefix	string	Prefix for output filenames. Name will be <prefix>.<timestamp>.<output_format>
timeout_ms	int	Timeout for waiting for pointclouds in ms.

Example:

ros2 run hector_pointcloud_io pointcloud_saver --ros-args -p topic:=/pointcloud_topic -p output_folder:=/path/to/save/folder -p output_format:=vtk -p output_filename_prefix:=my-pointcloud-prefix

All these parameters can be reconfigured. When the service is called using the std_srvs::srv::Trigger, it will wait for a message on the given topic and save it to the given folder with the filename <prefix>.<timestamp>.<output_format>.

hector_pointcloud_decimator

Contains the pointcloud_decimator node.

pointcloud_decimator

This node reduces the pount count of a pointcloud and publishes them in a compressed format via point_cloud_transport. The desired ammount of points can be specified as either a fraction of the original point count or as a total number of points. There are currently two methods to decimate a pointcloud:
random picks points randomly from the pointcloud. This method should prevent noticeable patterns in the pointcloud, but will likely not match the desired point count/fraction precisely.
count picks points equally from the whole range of the pointcloud. This method should is the more performant and will match the desired point count/fraction.

Subscribed Topics

Topic	Type	Description
/pointcloud	sensor_msgs/msg/PointCloud2	Input topic for pointclouds

Published Topics

Topic	Type	Description
/pointcloud_decimated	point_cloud_transport	Output topic for decimated pointclouds

Services

None

Actions

None

Parameters

Parameter	Type	Default	Description
elimination_method	std::string	"count"	How the pointcloud is decimated (random/count)
elimination_quantifier	std::string	"fraction"	How the amount of points to be kept is quantified (fraction/count)
point_fraction	double	0.1	Fraction of points to keep (used if elimination_quantifier = "fraction")
point_count	int	1000	Number of points to keep (used if elimination_quantifier = "count")