Subscribes to your map topic and exports a mesh for use in Gazebo in the destination folder you specify. The mesh will have obstacles (tall boxes) corresponding to all occupied map squares. Requires a map to be publishing somewhere, and will probably work better if the map is static.

Default parameters are specified in config/defaults.yaml; the location of the YAML parameter file is also a launchfile argument. To change the defaults, make a new YAML parameter file, and run

ros2 launch map2gazebo map2gazebo.launch.py params_file:=params.yaml

Alternatively you could just edit the default parameter file (not recommended, but I can't stop you).

YAML parameters:

• map_topic: Topic that the map to convert is being published on.
• mesh_type: Can be "stl" or "dae"; sets whether to export the mesh as a stl (default) or as a Collada file. Note that dae files specify a color and that by default this color is black, which you will likely want to edit as it makes your world very hard to see. If exporting as dae, you will also need to modify models/map/model.sdf to specify map.dae instead of map.stl if you are planning to use gazebo_world.launch.
• occupied_thresh: Minimum threshold value for considering a cell occupied. Defaults to 1 (out of 100).
• box_height: Height of boxes in gazebo environment. Defaults to 2m.
• export_dir: Directory of output mesh Default to current directory.

NOTE:

trimesh needs the following soft dependencies to export Collada (.dae) files.

Theoretically you can install these with pip install trimesh[soft] but this failed for me, so I installed the needed ones myself.

1. Install the python dependencies with pip:

pip3 install --user trimesh
pip3 install --user numpy
pip3 install --user pycollada
pip3 install --user scipy
pip3 install --user networkx
pip3 install --user opencv-contrib-python 

2. Git clone map2gazebo and build package

mkdir -p map2gz_ros2_ws/src
cd map2gz_ros2_ws/src
git clone https://github.com/H-HChen/map2gazebo.git -b foxy-devel
cd ..
colcon build --symlink-install

After you launch SLAM applicatoin and make sure "/map" topic is published.

source install/local_setup.bash
ros2 launch map2gazebo map2gazebo.launch.py

Remember to turn off the node when the map is completely done

If you want to convert an existing map to stl model.

please modified map_dir and export_dir to directory on your PC.

python3 src/map2gazebo/src/map2gazebo_offline.py --map_dir /path/to/map/mememan.pgm --export_dir /path/to/export_dir