Deciding On a Physics Sim Tool

[DrakeProvost]

Physics simulators compatible with ROS2

• Gazebo
  • Pros:
    • Ryan has some experience with making it run
    • One of the more popular physics sim tools for ROS2
  • Cons:
    • Seems to have a steep learning curve
    • Ryan quite dislikes it
• Ignition Gazebo
  • Pros:
    • Like Gazebo but with some additional features
  • Cons:
    • Ryan has been unable to get it to run without segfaulting
• Webots
  • Pros:
    • actually runs, and compatible with ROS2
  • Cons:
    • seems to be less popular than Gazebo, so might have a smaller community

Related tools

• rviz
  • Rviz is a visualization software, allowing you to view gazebo data (if you're simulating) or real world data (if you're using a real robot). Rviz cannot do any physics simulation itself though.

[DrakeProvost]

I got Webots to successfully run on shatterdome. I need to find a way to add Webots to the docker image (the instructions below require stdin responses during sudo apt-get install webots (to specify the keyboard's country of origin), which won't work for building an image), but here are the steps I took to make it work:

Webots installation steps I've followed (on shatterdome)

1. Launch ROS2 docker container.
2. Follow the Webots installation instructions for Linux using apt.

   You will likely get a sudo: apt-add-repository: command not found at the second step. To resolve, run sudo apt update; sudo apt install software-properties-common and then try the apt-add-repository command again.

3. Follow the instructions for building the webots_ros2 package.
4. To resolve a missing library for the webots demo, run sudo apt install libxtst6.
5. Run this demo using ros2 launch webots_ros2_demos armed_robots.launch.py. It should show two robotic arms moving cans around.

[LuckierDodge]

Looks like there might be a missing library we need to install.

[DrakeProvost]

Fixed, and updated the comment. Webots ran successfully on shatterdome, now I just need to find a way to include it in the Docker image (the technique described above doesn't work since it requires stdin responses while building).

[DrakeProvost]

I got a docker image with both ROS2 and Webots running! 🙌

To run a demo (on shatterdome):

1. Launch the webots_ros2_foxy docker container

2. Build the webots_ros2 package in a ROS2 workspace:

   source /opt/ros/$ROS_DISTRO/local_setup.bash
   
   # Retrieve the sources
   cd /path/to/ros2_ws
   git clone --recurse-submodules -b $ROS_DISTRO https://github.com/cyberbotics/webots_ros2.git src/webots_ros2
   
   # Check dependencies
   rosdep update
   rosdep install --from-paths src --ignore-src --rosdistro $ROS_DISTRO
   
   # Building packages
   colcon build
   
   # Source this workspace (careful when also sourcing others)
   source install/local_setup.bash

3. Run this demo using ros2 launch webots_ros2_demos armed_robots.launch.py. (For some reason this demo is missing the two robotic arms when I run it, but webots launches successfully and responds to interaction so I think webots itself is functional.)

[DrakeProvost]

Webots is already seeming like an attractive choice, but GPU acceleration with shatterdome's nvidia graphics card might make it even better. Here are instructions for that, which I haven't tried yet.