Switching between a VR and Desktop configuration with a ScriptableObject

We wanted to build a single project experience that included first class support for VR and at the same time worked well in a desktop environment.

Builds

We decided on having dedicated builds for desktop and VR. We wanted the ability to turn off VR. To do this we needed a couple of things.

1. Some way of configuring the project to be in VR or Desktop mode.
2. A way for the project to know what mode it was in and spawn correct player prefab
3. Unload VR related loaders.

Configuration

Configuration is handled by a ScriptableObject that looks something like the following:

[CreateAssetMenu]
public class GlobalConfiguration : ScriptableObject
{
    [HideInInspector]
    public bool useVR;

    public void TurnVROn()
    {
        // ...
    }

    public void TurnVROff()
    {
        // ...
    }
}

A custom inspector is used to introduce a button that will trigger the TurnVROn and TurnVROff functions.

Configuring VR Loaders

The following chunk of code will assign a loader.

XRGeneralSettingsPerBuildTarget buildTargetSettings = null;
EditorBuildSettings.TryGetConfigObject(XRGeneralSettings.k_SettingsKey, out buildTargetSettings);
XRGeneralSettings settings = buildTargetSettings.SettingsForBuildTarget(BuildTargetGroup.Standalone);      
XRPackageMetadataStore.AssignLoader(settings.Manager, typeof(Unity.XR.OpenVR.OpenVRLoader).FullName, BuildTargetGroup.Standalone);

Lets break down each of the lines.

1. XRGeneralSettingsPerBuildTarget buildTargetSettings = null;

   We are creating a variable to store our XRGeneralSettingsPerBuildTarget in.

2. EditorBuildSettings.TryGetConfigObject(XRGeneralSettings.k_SettingsKey, out buildTargetSettings);

   Retrieve the build target settings and store them into buildTargetSettings.

3. XRGeneralSettings settings = buildTargetSettings.SettingsForBuildTarget(BuildTargetGroup.Standalone);

   Get the XR settings for the Standalone (BuildTargetGroup.Standalone) build.

4. XRPackageMetadataStore.AssignLoader(settings.Manager, typeof(Unity.XR.OpenVR.OpenVRLoader).FullName, BuildTargetGroup.Standalone);

   Turn the OpenVRLoader on.

If we focus on line 4, we could also do XRPackageMetadataStore.RemoveLoader(...) to remove a loader.

Other types of loaders can be removed / added by changing the loader type from OpenVR to whatever loader is being used.

See also:

• Unity XR Management Documentation

Prefab Management

Prefab management is fairly straightforward. Simply have a PlayerSpawner that will look at the globalconfiguration.useVR value and spawn either a VR prefab or a Desktop prefab depending on the scenario. When the prefab is spawned a game event is triggered to let the scene know so it can self-configure from there.