ROS2 For Unity is a high-performance communication solution to connect Unity3D and ROS2 ecosystem in a ROS2 "native" way. Communication is not bridged as in several other solutions, but instead it uses ROS2 middleware stack (rcl layer and below), which means you can have ROS2 nodes in your simulation. Advantages of this module include:
- High performance - higher throughput and considerably lower latencies comparing to bridging solutions.
- Your simulation entities are real ROS2 nodes / publishers / subscribers. They will behave correctly with e.g. command line tools such as
ros2 topic
. They will respect QoS settings and can use ROS2 native time. - The module supplies abstractions and tools to use in your Unity project, including transformations, sensor interface, a clock, spinning loop wrapped in a MonoBehavior, handling initialization and shutdown.
- Supports all standard ROS2 messages.
- Custom messages are generated automatically with build, using standard ROS2 way. It is straightforward to generate and use them without having to define
.cs
equivalents by hand. - The module is wrapped as a Unity asset.
Supported OSes:
- Ubuntu 22.04 (bash)
- Ubuntu 20.04 (bash)
- Windows 10 (powershell)
Supported ROS2 distributions:
- Foxy
- Galactic
- Humble
Supported Unity3d:
- 2020+
Older versions of Unity3d may work, but the editor executable most probably won't be detected properly by deployment script. This would require user confirmation for using unsupported version.
This asset can be prepared in two flavours:
- standalone mode, where no ROS2 installation is required on target machine, e.g., your Unity3D simulation server. All required dependencies are installed and can be used e.g. as a complete set of Unity3D plugins.
- overlay mode, where the ROS2 installation is required on target machine. Only asset libraries and generated messages are installed therefore ROS2 instance must be sourced.
Note: The releases are built in overlay mode.
The best way to start quickly is to use our releases.
You can download pre-built releases of the Asset that support both platforms and specific ros2 and Unity3D versions.
Note: The project will pull
ros2cs
into the workspace, which also functions independently as it is a more general project aimed at anyC# / .Net
environment. It has its own README and scripting, but for building the Unity Asset, please use instructions and scripting in this document instead, unless you also wish to run tests or examples forros2cs
.
Please see OS-specific instructions:
Custom messages can be included in the build by either:
- listing them in
ros2_for_unity_custom_messages.repos
file, or - manually inserting them in
src/ros2cs
directory. If the folder doesn't exist, you must pull repositories first (see building steps for each OS).
- Perform building steps described in the OS-specific readme or download pre-built Unity package. Do not source
ros2-for-unity
norros2cs
project into ROS2 workspace. - Open or create Unity project.
- Import asset into project:
- copy
install/asset/Ros2ForUnity
into your projectAssets
folder, or - if you have deployed an
.unitypackage
- import it in Unity Editor by selectingImport Package
โCustom Package
- copy
Prerequisites
- If your build was prepared with
--standalone
flag then you are fine, and all you have to do is run the editor
otherwise
- source ROS2 which matches the
Ros2ForUnity
version, then run the editor from within the very same terminal/console.
Initializing Ros2ForUnity
- Initialize
Ros2ForUnity
by creating a "hook" object which will be your wrapper around ROS2. You have two options:ROS2UnityComponent
based onMonoBehaviour
which must be attached to aGameObject
somewhere in the scene, then:using ROS2; ... // Example method of getting component, if ROS2UnityComponent lives in different GameObject, just use different get component methods. ROS2UnityComponent ros2Unity = GetComponent<ROS2UnityComponent>();
- or
ROS2UnityCore
which is a standard class that can be created anywhereusing ROS2; ... ROS2UnityCore ros2Unity = new ROS2UnityCore();
- Create a node. You must first check if
Ros2ForUnity
is initialized correctly:private ROS2Node ros2Node; ... if (ros2Unity.Ok()) { ros2Node = ros2Unity.CreateNode("ROS2UnityListenerNode"); }
Publishing messages:
- Create publisher
private IPublisher<std_msgs.msg.String> chatter_pub; ... if (ros2Unity.Ok()){ chatter_pub = ros2Node.CreatePublisher<std_msgs.msg.String>("chatter"); }
- Send messages
std_msgs.msg.String msg = new std_msgs.msg.String(); msg.Data = "Hello Ros2ForUnity!"; chatter_pub.Publish(msg);
Subscribing to a topic
- Create subscriber:
private ISubscription<std_msgs.msg.String> chatter_sub; ... if (ros2Unity.Ok()) { chatter_sub = ros2Node.CreateSubscription<std_msgs.msg.String>( "chatter", msg => Debug.Log("Unity listener heard: [" + msg.Data + "]")); }
- Create a top-level object containing
ROS2UnityComponent.cs
. This is the centralMonobehavior
forRos2ForUnity
that manages all the nodes. Refer to class documentation for details. - Add
ROS2TalkerExample.cs
script to the very same game object. - Add
ROS2ListenerExample.cs
script to the very same game object.Note: Each example script looks for
ROS2UnityComponent
in its own game object. However, this is not a requirement, just example implementation. - Once you start the project in Unity, you should be able to see two nodes talking with each other in Unity Editor's console or use
ros2 node list
andros2 topic echo /chatter
to verify ros2 communication.
Open-source release of ROS2 For Unity was made possible through cooperation with Tier IV. Thanks to encouragement, support and requirements driven by Tier IV the project was significantly improved in terms of portability, stability, core structure and user-friendliness.