two terminals to input two point clouds and perform two conversions

[lina11116666]

Use two terminals to input two point clouds respectively, one called /trans_cloud and the other called /camera/depth/color/points, and convert the two point clouds to lidar, and output one called scan1 and the other called scan2 respectively. The following are the modifications I made to the launch file. Do I need to make any modifications to the cpp file of the conversion node?
from launch import LaunchDescription
from launch.actions import DeclareLaunchArgument
from launch.substitutions import LaunchConfiguration
from launch_ros.actions import Node

lidar ：
def generate_launch_description():
return LaunchDescription([
DeclareLaunchArgument(
name='scanner', default_value='scanner',
description='Namespace for sample topics'
),
Node(
package='pointcloud_to_laserscan', executable='dummy_pointcloud_publisher',
remappings=[('cloud', '/trans_cloud'),('scan', '/trans_scan')],
name='cloud_publisher'
),
Node(
package='pointcloud_to_laserscan', executable='pointcloud_to_laserscan_node',
remappings=[('cloud_in', '/trans_cloud'), ('scan', '/scan1')],
parameters=[{
'target_frame': 'base_footprint',
'transform_tolerance': 0.01,
'min_height': 0.25,
'max_height': 1.0,
'angle_min': -3.14, # -M_PI/2
'angle_max': 3.14, # M_PI/2
'angle_increment': 0.0087, # M_PI/360.0
'scan_time': 0.25,
'range_min': 0.10,
'range_max': 20.0,
'use_inf': True,
'inf_epsilon': 1.0,
}],
name='pointcloud_to_laserscan'
)
])

camera：
from launch import LaunchDescription
from launch.actions import DeclareLaunchArgument
from launch.substitutions import LaunchConfiguration
from launch_ros.actions import Node

def generate_launch_description():
return LaunchDescription([
DeclareLaunchArgument(
name='scanner', default_value='scanner',
description='Namespace for sample topics'
),
Node(
package='tf2_ros',
executable='static_transform_publisher',
name='static_transform_publisher',
arguments=['0', '0', '0', '0', '0', '0', '1', 'base_footprint', 'camera_link']
),
Node(
package='pointcloud_to_laserscan', executable='pointcloud_to_laserscan_node',
remappings=[('cloud_in', '/camera/depth/color/points'), ('scan', '/scan2')],
parameters=[{
'target_frame': 'base_footprint',
'transform_tolerance': 0.01,
'min_height': 0.1,
'max_height': 1.5,
'angle_min': -3.14, # -M_PI/2
'angle_max': 3.14, # M_PI/2
'angle_increment': 0.0087, # M_PI/360.0
'scan_time': 0.25,
'range_min': 0.10,
'range_max': 5.0,
'use_inf': True,
'inf_epsilon': 1.0,
}],
name='pointcloud_to_laserscan'
)
])
I don't know how to modify the pointcloud_to_laserscan_node.cpp file. Can I just modify these two lines?
sub_.subscribe(this, "/trans_cloud",A qos.get_rmw_qos_profile());
sub_.subscribe(this, "/camera/depth/color/points", qos.get_rmw_qos_profile());

[Rayman]

You don't need to modify any of the code in the pointcloud_to_laserscan package. You can solve your problem with remapping:

• create a new launch file
• launch pointcloud_to_laserscan with a remapping from cloud_in to trans_cloud and scan to scan1
• launch pointcloud_to_laserscan with a remapping from cloud_in to camera/depth/color/points and scan to scan2

But I think these questions can be better asked on https://robotics.stackexchange.com/

[lina11116666]

Does it mean that I still keep the following content in the node cpp file like sub_.subscribe(this, "cloud_in",A qos.get_rmw_qos_profile());? Then start two launch files, do I need to modify the launch file above?

[Rayman]

Yes, just keep it at the default. But you don't need to compile this package from source. Just install ros-jazzy-pointcloud-to-laserscan with apt-get.

[lina11116666]

'Just use apt-get to install ros-jazzy-pointcloud-to-laserscan', can I ask how to do this step? Because the code I got now is directly downloaded and installed from the source code, is this method not possible?