Mixed Reality Toolkit for ROS2 Overview

The MRTK for ROS is being developed in the open: Feature requests are very much welcome at the issues page.

The Robot Operating system - also called ROS [^1] - is an open source middleware for creating Robots. This repository implements glue which connects your Mixed Reality Robotics application with Robots and infrastructure using ROS2. ROS2 runs directly on the Hololens without going through ROS Bridge - reducing latency and improving network efficiency. The ROS2 MRTK extension works with ROS2.net[^2] within the Unity Game engine, allowing you to write ROS2-like code directly in Unity.

The Mixed Reality Toolkit is an Open Source framework for building Virtual Reality and Augmented Reality applications, which target numerous platforms - including Hololens.

Getting started with ROS2 on Hololens 2.

This depends on ROS2 Foxy UPM supplied by Microsoft. Windows is required for Hololens and Windows Mixed Reality development. MRTK for ROS2 development will not be supported on other platforms.

Prerequsitites

• Unity 2020.4 or later
• Microsoft Mixed Reality Toolkit
• Nuget for Unity 3.04 or later
• Microsoft Mixed Reality QR Nuget
• Download the Unity release for the ROS2 native from http://aka.ms/ros/mrtk_native
• Download the Unity release for the Mixed Reality Toolit for ROS2 from http://aka.ms/ros/mrtk
• Long Pathes enabled on Windows. Run this command from an administrative command prompt reg add HKLM\SYSTEM\CurrentControlSet\Control\FileSystem /v LongPathsEnabled /t REG_DWORD /d 1 /f'

Create your application

• Create a 3D Unity application

• Use the Microsoft Mixed Reality Feature Tool, and select the following features:

  • Azure Mixed Reality Services
  • Azure Spatial Anchors SDK Core
  • Azure Spatial Anchors SDK for iOS
  • Azure Spatial Anchors SDK for Windows
  • Mixed Reality Toolkit
  • Mixed Reality Toolkit Extensions
  • Mixed Reality Toolkit Foundation
  • Mixed Reality Standard Assets
  • Mixed Reality Toolkit Tools
  • Platform Support
  • Mixed Reality OpenXR Plugin
  • Spatial Audio
  • Microsoft Spatializer
  • World Locking Tools
  • WLT Core

• Wait for Unity to deploy these components.

  • If asked about the new Input System, select Yes.

• When Unity restarts, you should now see a window titled MRTK Project Configurator

  • Select Unity OpenXR Plugin
  • Select Show XR Plug-in Management
  • In the new window, with the monitor icon on the tab, select OpenXR.
  • Switch to the Microsoft icon, ans select OpenXR
  • Close the Unity Configuration Window
  • Return to the MRTK Project Configurator Window and select Apply Settings, then select Next
  • Select Microsoft Spatializer in the Audio Spatializer dropdown, then click Apply

• When Unity Restarts (again), Select the Mixed Reality Menu item, Toolkit, Add to Scene and Configure

• Add Nuget for unity to your application by double clicking the the NuGetForUnity.3.0.2.unitypackage. Import the assets into your project.

• In the Menu for Unity, select NuGet, then Manage Packages.

• In the Search edit box, enter Microsoft.MixedReality.QR, then click search. Install 0.5.3 or later.

• In the Window Menu, select Package Manager.

• Select +, then Add Package from tarball. select the Unity release for ROS2 Native downloaded above.

• Select +, then Add Package from tarball. select the Unity release for the Mixed Reality Toolkit for ROS2 downloaded above.

• In the Project tree view in Unity, expand ROS2 and ROS2.net Native components for Unity and locate the link.xml file. Drag and copy this file into your asset folder.

  • This is needed to prevent optimizations which break ROS2.net Messages.

• Configure your project for Hololens:

  • Select Edit then Project Settings
  • Select Player. Select the Windows icon.
  • Under Capabilities, ensure that the following are checked:
  • InternetClient
  • InternetClientServer
  • PrivateNetworkClientServer
  • WebCam
  • Microphone
  • SpatialPerception
  • Select File Then Build Settings
  • Select Add Open Scenes to add your current scenes to the project.
  • Select Universal Windows Platform and Switch Plaform if needed.
  • Select Build
  • In the save dialog, right click on the background and select New Folder, name it App, ensure App is selected, then click Select Folder
  • Open the resulting Visual Studio Solution in the App folder
  • Configure Visual Studio
  • Select the Release build type. (This is important, as the ROS2 binaries are only delivered as release)
  • Select ARM64.
  • Build and Deploy

You can now add scenes from the ROS MRTK extension or use individual components in your application.

Sample Scene to bootstrap your application

One you have configured the application above, you can now add components to your scene to define your application. A Sample scene is provided which demonstrates spatial pinning and Lidar visualization.

• In the Unity Package Manager Window, select ROS2 and ROS2.net UI components for Unity.
• Under the Samples dropdown, select Basic ROS World and select Import.
• Drag this scene to the Unity Hierarchy Window.
• Remove any existing scenes.

Contributions

Contributions are welcome. Refer to the Contribution Process for more details.

[^1]: ROS is a trademark of Open Robotics. [^2]: ROS2.net is maintained by the ROS2.net maintainers and community.