Rosject - Mapping section rviz and map_server

Course Support ROS2 Navigation
1

Hi community,

I am working on the Mapping section of the Rosject. I found that if I use a single launch file to launch map_server and rviz2, rviz2 will not receive the map topic from map_server. I believe it is because the map_server publishes the map topic before the rviz2 has launched. Because if I call the load map service, the rviz2 can show the map correctly.

Is there any method to solve this or should I write them in separate launch files? Below is my launch file.

import os

import launch.actions
import launch_ros.actions
from ament_index_python.packages import get_package_share_directory
from launch import LaunchDescription
from launch_ros.actions import Node

def generate_launch_description():
    
    rviz_config_dir = <path-to-rviz-config>
    map_file = <path-to-my-map>

    return LaunchDescription([
        Node(
            package='nav2_map_server',
            node_executable='map_server',
            node_name='map_server',
            output='screen',
            parameters=[{'use_sim_time': True}, 
                        {'yaml_filename':map_file} 
                       ]),

        Node(
            package='rviz2',
            node_executable='rviz2',
            node_name='rviz2',
            arguments=['-d', rviz_config_dir],
            parameters=[{'use_sim_time': True}],
            output='screen'
            ),

        Node(
            package='nav2_lifecycle_manager',
            node_executable='lifecycle_manager',
            node_name='lifecycle_manager_localization',
            output='screen',
            parameters=[{'use_sim_time': True},
                        {'autostart': True},
                        {'node_names': ['map_server']}])            
        ])

Thanks,
Alan

2

Hello @alan0428a ,

Have you tried unchecking/checking again the Map Display checkbox in Rviz2? I’ve encountered similar issues with RViz2 that could be solved just by doing that.

3

Hi @albertoezquerro ,

Thanks for the reply. Unfortunately, checking/unchecking the Map Display doesn’t work for me. It does not show the map.

4

Hello @alan0428a ,

Having a look to your launch file, I can see that you didn’t specify the path to your files (rviz configuration and map):

rviz_config_dir = <path-to-rviz-config>
map_file = <path-to-my-map>

Probably here is the problem.