Ray cast platform support

The AR Foundation XRRaycastSubsystem is supported on the ARCore, ARKit, Microsoft HoloLens, Meta OpenXR, and XR Simulation platforms, as shown in the following table:

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

Check for ray casting support

Your app can check at runtime whether a provider plug-in supports ray casting on the user's device. Use the following example code to check whether the device supports ray casting:

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

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 XRRaycastSubsystem. Each optional feature is defined by a Descriptor Property of the XRRaycastSubsystemDescriptor, which you can check at runtime to determine whether a feature is supported. Refer to Check for optional feature support for a code example to check whether a feature is supported.

Feature	Descriptor Property	Description
Viewport based raycast	supportsViewportBasedRaycast	Whether the provider supports casting a ray from a screen point.
World based raycast	supportsWorldBasedRaycast	Whether the provider supports casting an arbitrary ray.
Trackable types	supportedTrackableTypes	The types of trackables against which ray casting is supported.
Tracked raycasts	supportsTrackedRaycasts	Whether tracked raycasts are supported. A tracked raycast is repeated over time and the results are updated automatically.

Optional feature platform support

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

Feature	ARCore	ARKit	Meta OpenXR	XR Simulation
Viewport based raycast	Yes	Yes
World based raycast	Yes		Yes	Yes
Tracked raycasts	Yes	iOS 13+

Note

The Meta OpenXR ray cast implementation performs calculations in Unity world space and does not rely on native platform implementation. Refer to the Meta OpenXR Ray cast documentation to understand ray casting on Meta OpenXR devices.

Supported trackables

ARRaycastManager supports ray casting against most TrackableTypes. The following table shows which trackables each platform supports ray casting against:

TrackableType	ARCore	ARKit	Meta OpenXR	XR Simulation
BoundingBox			Yes
Depth	Yes
Face
FeaturePoint	Yes	Yes		Yes
Image
Planes	Yes	Yes		Yes
PlaneEstimated	Yes	Yes		Yes
PlaneWithinBounds	Yes	Yes	Yes	Yes
PlaneWithinInfinity		Yes		Yes
PlaneWithinPolygon	Yes	Yes		Yes

Check for optional feature support

Your app can check at runtime whether a ray casting provider supports any optional features on the user's device. The XRRaycastSubsystemDescriptor contains Boolean properties for each optional feature that tell you whether 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<ARRaycastManager>();

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

    if (manager.descriptor.supportsWorldBasedRaycast)
    {
        // World based ray casts are supported.
    }
}

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