pgm_map_creator

A Gazebo Classic plugin and ROS utility for generating occupancy .pgm maps from a simulated Gazebo world. These maps can be used in ROS localization and navigation pipelines.

Background

I adapted this repository based on OSRF's collision_map_creator_plugin by Stephen Brawner. It is used in Udacity's Robotics Program with Udacity's fork.

The package seems to have helped numerous roboticists in their work over the years. With ROS 1 going EOL I refreshed it with LLMs' help to ensure it works with Noetic.

If you are looking for ROS 2 option, @arshadlab built gazebo_map_creator with great improvements and documentation for his robotics projects.

Environment

Tested on Ubuntu 20.04, ROS Noetic, Gazebo 11.

Easiest way to set up is using OSRF's Noetic docker image: osrf/ros:noetic-desktop-full. Need X11 shenanigans to bring up GUI if you need it.

docker run -it --rm --net=host --user $(id -u):$(id -g) --device /dev/dri --env="DISPLAY" --env="QT_X11_NO_MITSHM=1" --volume="/tmp/.X11-unix:/tmp/.X11-unix:rw"  --volume="/home/$(id -u):/home/$(id -u):rw"  --name ros_noetic_gazebo osrf/ros:noetic-desktop-full bash

Setup

1. Clone into your Catkin workspace

mkdir -p ~/catkin_ws/src
cd ~/catkin_ws/src
git clone https://github.com/hyfan1116/pgm_map_creator.git
cd ..
catkin_make
source devel/setup.bash

2. Add the plugin to your Gazebo world

Copy your .world file to the world/ folder if needed. Then, add the plugin line after the <world> tag:

<plugin filename="libcollision_map_creator.so" name="collision_map_creator"/>

Example:

<world name="default">
  <plugin filename="libcollision_map_creator.so" name="collision_map_creator"/>
  ...
</world>

Usage

1. Start the Gazebo server

gzserver src/pgm_map_creator/world/<YOUR MAP>

2. Launch the map creation request node

roslaunch pgm_map_creator request_publisher.launch

This will send a request to the plugin to rasterize the environment and write the .pgm file to the map/ folder. A .pgm file will be generated representing the occupancy map of the specified region. It can be used directly with ROS's map_server by pairing it with a .yaml map file.

Configuration

Edit the arguments inside the request_publisher.launch file to define:

• corners: (x,y) corner pairs in clockwise order starting from upper-left
• height: height from which to raycast downward
• resolution: map resolution in meters/pixel
• filename: output file path
• threshold: pixel threshold for marking occupied space

Example (inside request_publisher.launch):

<arg name="corners" default="(1,1)(5,1)(5,5)(1,5)"/>
<arg name="height" default="2.0"/>
<arg name="resolution" default="0.05"/>
<arg name="filename" default="$(find pgm_map_creator)/map/my_map"/>
<arg name="threshold" default="100"/>

Acknowledgements

This package is adapted from the collision_map_creator_plugin by Stephen Brawner, developed as part of the Gazebo Custom Messages Tutorial.

The Gazebo Perfect Map Generator also packaged original plugin for easier use within a ROS-based simulation workflow for Hydro and Indigo.