# RCLGD [](https://doi.org/10.5281/zenodo.18440938) An implementation of a ros2 client library for the Godot Engine based on [ROS Babel Fish](https://github.com/LOEWE-emergenCITY/ros_babel_fish)

Features

As for now only the basic set of the rclcpp api are implemented, keep in mind this is highly experimental and not suited yet for production. But it serves as the groundbase for implementing awesome simulation environments and visualizers using the powerful features of the godot engine.

• rclgd Singleton
• Dynamic Msg Type Support
• Nodes
• Publishers
• Subscribers
• Service Clients
• Service Servers
• Timers
• Action Clients & Servers
• Parameters
• TF2 Publishers and Listeners -> Including stamped lookups, time travel and frame-graph introspection
• TF2 Listeners And Broadcasters as 3D Nodes in godot (Will be deprecated in future update)
• Node and TF Namespacing
• ROS Graph Inspection
• QoS -> Through QoS RosQoS resource
• Godot template project
• Godot Editor Support -> Pseudo-Static Type Wrappers
• Simulation Time -> -p publish_sim_time:=true publishes the Godot physics clock on /clock; the standard -p use_sim_time:=true makes clocks and timers follow /clock
• Native RCLGD packages in colcon

Repository layout

The suite is split into independently releasable ROS 2 packages:

The system-test suite (rclgd_tests, itself a native rclgd package) is maintained separately so this repository contains only the releasable packages.

Installation

From apt (recommended)

rclgd is published to the ROS 2 build farm, so on a machine with the ROS 2 apt repositories configured you can install the whole suite in one command:

sudo apt update
sudo apt install ros-jazzy-rclgd

This installs all three packages plus the pinned Godot editor binary — the install is complete out of the box, no extra step. Replace jazzy with your ROS 2 distribution if needed (rclgd is developed and tested on Jazzy).

source /opt/ros/jazzy/setup.bash
ros2 rclgd doctor   # verify the install

Building from source

Build from source to track main, hack on rclgd, or target a different Godot version. Clone into your workspace, install dependencies, build and source. The rclgd build downloads the pinned Godot editor binary (SHA-512 verified against the official release sums) and installs it as lib/rclgd/godot-bin, next to librclgd.so — provisioning happens inside the build, so the install is complete out of the box with no separate setup step.

git clone --recurse-submodules https://github.com/Ozuba/rclgd.git src/rclgd
rosdep install --from-paths src --ignore-src -y -r
colcon build --packages-up-to rclgd
source install/setup.bash

The build installs exactly the Godot version librclgd was compiled against (the version of the godot-cpp bindings; recorded in share/rclgd/godot_version). To use a different Godot version, retarget the godot-cpp submodule to the corresponding branch, edit GODOT_VERSION and the GODOT_SHA512_* pins in rclgd/CMakeLists.txt, and rebuild.

Command line tools

rclgd ships a ros2 rclgd command:

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