Session platform support

Understand the features of the session subsystem, and which platforms support these features.

AR Foundation requires that all provider implementations on all platforms support the session feature, as shown in the following table:

Provider plug-in	Session supported	Provider documentation
Google ARCore XR Plug-in	Yes	Session (ARCore)
Apple ARKit XR Plug-in	Yes	Session (ARKit)
Apple visionOS XR Plug-in	Yes	N/A
Unity OpenXR: Meta	Yes	Session (Meta OpenXR)
Unity OpenXR: Android XR	Yes	Session (Android XR)
XR Simulation	Yes	Session (XR Simulation)

Optional features

The following table lists the optional features of the session subsystem. Each optional feature is defined by a Descriptor Property of the XRSessionSubsystemDescriptor, which you can check at runtime to determine whether your target platform supports a feature. Refer to Check for optional feature support for a code example to check whether a feature is supported.

Feature	Descriptor Property	Description
Install (Deprecated)	supportsInstall	Whether the session supports the update or installation of session software.
Match frame rate	supportsMatchFrameRate	Whether the session supports matching the AR frame rate to the Unity frame rate.

Optional feature platform support

The following table lists whether certain XR plug-in providers support each optional feature:

Feature	ARCore	ARKit	visionOS	Meta OpenXR	Android XR	XR Simulation
Install (Deprecated)	Yes
Match frame rate	Yes	Yes

Check for optional feature support

Your app can check at runtime whether a session provider supports any optional features on the user's device. The XRSessionSubsystemDescriptor contains Boolean properties for each optional feature that tell you whether they're supported.

Refer to the following example code to learn how to check for optional feature support:

void CheckForOptionalFeatureSupport(ARSession manager)
{
    // Use manager.descriptor to determine which optional features
    // are supported on the device. For example:

    if (manager.descriptor.supportsMatchFrameRate)
    {
        // Match frame rate is supported.
    }
}

AR support on mobile devices

Some mobile devices require additional software to run AR. You can request the device to install or update necessary XR software. You can learn more about AR support on mobile devices, by referring to the ARCore and ARKit documentation.

Refer to the following section to install XR software on your target device if required.

Install XR software on mobile devices

To attempt to install XR software, pass InstallSoftwareIfNeeded to TryStartAsync.

When AR isn't supported on the device, TryStartAsync returns an XRResultStatus with a StatusCode.Unsupported status code, which you can check to provide an alternative experience.

The following example installs required software if needed, starts the session, and handles an unsupported device:

async Awaitable InstallAndStartSession(XRSessionSubsystem sessionSubsystem, CancellationToken cancellationToken)
{
    // Pass InstallSoftwareIfNeeded so the subsystem checks for, and installs,
    // any required AR software before it starts.
    var result = await sessionSubsystem.TryStartAsync(
        cancellationToken, XRSubsystemStartOptions.InstallSoftwareIfNeeded);

    if (result.statusCode == XRResultStatus.StatusCode.Unsupported)
    {
        // AR is not supported on this device. Start a fallback (non-AR) experience instead.
        return;
    }

    if (result.IsError())
    {
        // AR is supported, but the required software could not be installed
        // (for example, the user declined the installation).
        return;
    }

    // The session started successfully and AR is now running.
}

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