Building Bonxai and NavMap Maps from a Recorded ROSBag

This HowTo shows how to generate both Bonxai and NavMap representations from a recorded ROSBag containing a PointCloud2 map, typically produced by a SLAM algorithm. The input point cloud must be referenced to the world or map frame.

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Overview 

You will:

Align coordinate frames (world → map if needed).
Play a pre-recorded ROS bag containing the /map point cloud.
Launch EasyNav with both BonxaiMapsManager and NavMapMapsManager to build the two maps simultaneously.
Visualize both in RViz2.
Save the resulting maps to disk.

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1. Align the Frames (world → map)

If your ROS bag publishes a PointCloud2 in the frame world, you need to publish a static transform so that the map managers receive data in map.

In a new terminal, run:

ros2 run tf2_ros static_transform_publisher --frame-id world --child-frame-id map

Keep this terminal running for the entire session. If your point cloud is already in the map frame, skip this step.

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2. Play the ROSBag 

Next, replay the recorded ROS bag containing the point cloud map.

The example bag is about 1600 seconds long. To jump close to the end (around 1500 seconds, when the map is already dense) but still leave a few seconds to build the maps, run:

ros2 bag play rosbag_excavation_urjc_map_tf_only --clock --start-offset 1500

This will replay the point cloud topic /map and the TF tree needed by the map managers.

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3. Launch EasyNav with Bonxai and NavMap Maps Managers 

In a new terminal, launch EasyNav System with both map managers active.

ros2 run easynav_system system_main \
  --ros-args \
  --params-file /absolute/path/to/bonxai-navmap.dummy.params.yaml \
  -r /maps_manager_node/navmap/incoming_pc2_map:=/map \
  -r /maps_manager_node/bonxai/incoming_pc2_map:=/map

This setup assumes:

The input cloud topic is /map.
The QoS settings are standard (reliable, transient local).
Both managers will build their respective maps automatically.

The file bonxai-navmap.dummy.params.yaml defines dummy plugins for all nodes except maps_manager_node.

Example configuration:

controller_node:
  ros__parameters:
    use_sim_time: true
    controller_types: [dummy]
    dummy:
      rt_freq: 30.0
      plugin: easynav_controller/DummyController
      cycle_time_nort: 0.01
      cycle_time_rt: 0.001

localizer_node:
  ros__parameters:
    use_sim_time: true
    localizer_types: [dummy]
    dummy:
      rt_freq: 50.0
      freq: 5.0
      reseed_freq: 0.1
      plugin: easynav_localizer/DummyLocalizer
      cycle_time_nort: 0.01
      cycle_time_rt: 0.001

maps_manager_node:
  ros__parameters:
    use_sim_time: true
    map_types: [bonxai, navmap]
    bonxai:
      freq: 10.0
      plugin: easynav_bonxai_maps_manager/BonxaiMapsManager
      package: easynav_indoor_testcase
      bonxai_path_file: maps/excavation_urjc.pcd
    navmap:
      freq: 10.0
      plugin: easynav_navmap_maps_manager/NavMapMapsManager
      package: easynav_indoor_testcase
      navmap_path_file: maps/excavation_urjc.navmap

planner_node:
  ros__parameters:
    use_sim_time: true
    planner_types: [dummy]
    dummy:
      freq: 1.0
      plugin: easynav_planner/DummyPlanner
      cycle_time_nort: 0.2
      cycle_time_rt: 0.001

sensors_node:
  ros__parameters:
    use_sim_time: true
    forget_time: 0.5
    perception_default_frame: odom

system_node:
  ros__parameters:
    use_sim_time: true
    use_real_time: false
    position_tolerance: 0.3
    angle_tolerance: 0.15

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4. NavMap Build Parameters 

The NavMapMapsManager allows tuning of mesh generation parameters via YAML configuration. You may add the following optional fields under the navmap plugin section.

Available parameters

Parameter	Description
`resolution`	In-plane sampling resolution (m) for voxelization.
`max_edge_len`	Maximum triangle edge length (m).
`max_dz`	Maximum allowed vertical jump (m) between vertices.
`max_slope_deg`	Maximum slope (degrees) relative to the vertical axis.
`neighbor_radius`	Neighborhood radius (m) for triangle connectivity.
`k_neighbors`	Alternative to radius: number of nearest neighbors.
`min_area`	Minimum triangle area (m²) to reject degenerate faces.
`use_radius`	Use radius-based vs. k-NN connectivity. (bool)
`min_angle_deg`	Minimum interior angle (degrees) to avoid slivers.
`max_surfaces`	Keep only the N largest connected surfaces (0 = all).

These parameters allow fine control of NavMap mesh reconstruction quality.

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5. Visualize in RViz2 

Open RViz2 to monitor both map managers.

ros2 run rviz2 rviz2 --ros-args -p use_sim_time:=true

In RViz:

Add a PointCloud2 display for Bonxai maps. - Select the topic published by BonxaiMapsManager (e.g., /maps_manager_node/bonxai/map). - QoS: Transient Local. - You can visualize the cloud as boxes with configurable size for clearer 3D structure.
Add a NavMapDisplay (custom display type). - Select the topic published by NavMapMapsManager (e.g., /maps_manager_node/navmap/map). - QoS: Transient Local.

../_images/mapping_tut_bonxai.png — Bonxai map visualization in RViz.

../_images/mapping_tut_navmap.png — NavMap mesh visualization in RViz.

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6. Save the Maps 

When both maps are visible and complete, you can store them to disk using their respective map manager services.

Save NavMap

ros2 service call /maps_manager_node/navmap/savemap std_srvs/srv/Trigger

This saves the NavMap to /tmp/map.navmap. Rename and move it to your desired location (e.g. inside maps/).

Save Bonxai Map

ros2 service call /maps_manager_node/bonxai/savemap std_srvs/srv/Trigger

This saves the Bonxai point cloud to /tmp/bonxai_map.pcd.

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7. Summary 

You have:

✅ Aligned frames between world and map
✅ Played a recorded ROS bag with point cloud data
✅ Built Bonxai and NavMap maps simultaneously
✅ Visualized them in RViz
✅ Saved both maps to disk for future use

These maps can now be used in EasyNav navigation stacks (e.g. with the Costmap, GridMap, or NavMap planners).

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Next steps: