# Unity Setup Guide
This guide will explain in detail how to get started with the Snapdragon Spaces SDK in Unity.
# Prerequisites
VERSION
Please note that the recommended Unity Editor version to work with Snapdragon Spaces is 2020.3.17f1. Later versions of Unity Editor might work well, but have not been extensively tested. Version 2020.3.35f1 or higher is required, if MRTK3 (opens new window) is an additional requirement.
Android Build Support must be added when installing the Unity Editor to be able to export .apk files. The module can also be added afterwards through the Unity Hub.
# Import the package
The Snapdragon Spaces SDK comes as a package in form of a tarball file. Please follow the Unity instructions (opens new window) to import the package into the project.
WARNING
After importing the package, Unity might prompt you to enable the new input system. Click Yes to ensure full functionality with the OpenXR and XR Interaction Toolkit packages. If the old input system is needed in addition, the Active Input Handling value under Player Settings > Other Settings > Configuration can be set to both.
# Import the samples
The Snapdragon Spaces SDK package comes with sample assets to showcase how to use the services included in the package. To import them, simply pick the package in the package manager (located in the menu bar under Window > Package Manager) and click import on the Core Samples.
After the samples have been imported, there is a helper tool to add the sample scenes to the build settings by clicking Window > Snapdragon Spaces > Add Scenes to Build Settings in the menu bar.
# Change the project settings
To enable the Snapdragon Spaces OpenXR Plug-in, navigate to the project settings under Edit > Project Settings > XR Plug-in Management. Check the OpenXR plug-in as well as the Snapdragon Spaces feature group. Initially, there will be some project settings that have to be updated/fixed. To do so, click on the red exclamation mark next to OpenXR to step into the OpenXR Project Validation window. Click on the fix buttons next to the entries to apply the needed project settings. Apply the setting to enable both Input Systems last, as this may require a restart of the Editor.
# Enable Spaces features
Enable the features in the OpenXR settings that should be active during runtime. The current supported features and the respective AR Foundation manager or XR subsystem that can be used with it, is listed in the table below.
| Feature | AR Foundation/Spaces Manager | XR Subsystem |
|---|---|---|
| Base Runtime | AR Session (opens new window) AR Pose Driver (opens new window) | XRSessionSubsystem (opens new window) - |
| Spatial Anchors | AR Anchor Manager (opens new window) | XRAnchorSubsystem (opens new window) |
| Plane Detection | AR Plane Manager (opens new window) | XRPlaneSubsystem (opens new window) |
| Image Tracking | AR Tracked Image Manager (opens new window) | XRImageTrackingSubsystem (opens new window) |
| Hit Testing | AR Raycast Manager (opens new window) | XRRaycastSubsystem (opens new window) |
| Hand Tracking | Spaces Hand Tracking Manager | Spaces.XRHandTrackingSubsystem |
# Custom Controller Setup
The Snapdragon Spaces Unity package includes the possibility to spawn a controller upon startup of the application on the host device. This feature is enabled by default in the BaseRuntimeFeature, which is located under Edit > Project Settings > XR Plug-in Management > OpenXR > OpenXR Feature Groups > BaseRuntimeFeature (by clicking on the cog wheel).
If a custom implementation with different appearance and slightly different functionality is desired, an alternative controller archive can be build in the steps described in the custom controller section.
The resulting archive from these steps can then be included anywhere in the Assets folder of the Unity project, and the Use Custom Controller toggle has to be enabled (which requires the Launch Controller On Host option to be enabled as well).
WARNING
In some instances, adding a custom controller archive might lead to Gradle caching errors. In that case, removing the temporary Gradle project folder generated in the project folder under Temp > gradleOut might resolve the issue.