Anchors platform support

Anchors are supported on the ARCore, ARKit, HoloLens, Meta OpenXR, and XR Simulation platforms, as shown in the table below:

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

Check for support at runtime

Your app can check at runtime whether a provider plug-in supports anchors on the user's device. This is useful in situations where you are unsure if the device supports anchors, which may be the case if you are using AR Foundation with a third-party provider plug-in.

Use the following example code to check if the device supports anchors:

void Start()
{
    if (LoaderUtility
            .GetActiveLoader()?
            .GetLoadedSubsystem<XRAnchorSubsystem>() != null)
    {
        // XRAnchorSubsystem was loaded. The platform supports anchors.
    }
}

Note

This example code assumes that your app has already initialized XR.

By default XR initializes automatically when your app starts, but this is configurable via Project Settings > XR Plug-in Management > Initialize XR on Startup. Refer to the XR Plug-in Management End-user documentation for more detailed information about managing the XR Plug-in lifecycle.

Optional features

The following table lists the optional features of the anchor subsystem. Each optional feature is defined by a Descriptor Property of the XRAnchorSubsystemDescriptor, which you can check at runtime to determine if a feature is supported. The Description column lists the optional API that may or may not be implemented on each platform.

Tip

Check the API documentation to understand how each API behaves when the provider doesn't support a feature. For example, some methods may throw an exception if you call them when the feature isn't supported.

Feature	Descriptor Property	Description
Trackable attachments	supportsTrackableAttachments	Indicates whether the provider implementation supports the ability to attach an anchor to a trackable via TryAttachAnchor.
Synchronous add	supportsSynchronousAdd	Indicates whether the provider implementation supports the ability to synchronously add anchors via TryAddAnchor.
Save anchor	supportsSaveAnchor	Indicates whether the provider implementation supports the ability to persistently save anchors via TrySaveAnchorAsync.
Load anchor	supportsLoadAnchor	Indicates whether the provider implementation supports the ability to load persistently saved anchors via TryLoadAnchorAsync.
Erase anchor	supportsEraseAnchor	Indicates whether the provider implementation supports the ability to erase the persistent saved data associated with an anchor via TryEraseAnchorAsync.
Get saved anchor IDs	supportsGetSavedAnchorIds	Indicates whether the provider implementation supports the ability to get all saved persistent anchor GUIDs via TryGetSavedAnchorIdsAsync.
Async cancellation	supportsAsyncCancellation	Indicates whether the provider implementation supports cancelling async operations in progress using a CancellationToken.

Optional features support table

To understand the optional features that are implemented in each supported XR plug-in provider, refer to the following table:

Feature	ARCore	ARKit	HoloLens	Meta OpenXR	XR Simulation
Trackable attachments	Yes	Yes			Yes
Synchronous add	Yes	Yes
Save anchor				Yes
Load anchor				Yes
Erase anchor				Yes
Get saved anchor IDs
Async cancellation

Check for optional feature support

Your app can check at runtime whether an anchor provider supports any optional features on the user's device. The XRAnchorSubsystemDescriptor contains boolean properties for each optional feature that tell you if they are supported.

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

void CheckForOptionalFeatureSupport()
{
    // This is inefficient. You should re-use a saved reference instead.
    var manager = Object.FindAnyObjectByType<ARAnchorManager>();

    // Use manager.descriptor to determine which optional features
    // are supported on the device. For example:

    if (manager.descriptor.supportsTrackableAttachments)
    {
        // Trackable attachments are supported.
    }
}

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