Class XRImageTrackingSubsystem

A subsystem for detecting and tracking a preconfigured set of images in the environment.

Inheritance
object
SubsystemWithProvider
SubsystemWithProvider<XRImageTrackingSubsystem, XRImageTrackingSubsystemDescriptor, XRImageTrackingSubsystem.Provider>
TrackingSubsystem<XRTrackedImage, XRImageTrackingSubsystem, XRImageTrackingSubsystemDescriptor, XRImageTrackingSubsystem.Provider>
XRImageTrackingSubsystem
SimulationImageTrackingSubsystem
Implements
ISubsystem
Inherited Members
SubsystemWithProvider<XRImageTrackingSubsystem, XRImageTrackingSubsystemDescriptor, XRImageTrackingSubsystem.Provider>.OnCreate()
SubsystemWithProvider<XRImageTrackingSubsystem, XRImageTrackingSubsystemDescriptor, XRImageTrackingSubsystem.Provider>.OnStart()
SubsystemWithProvider<XRImageTrackingSubsystem, XRImageTrackingSubsystemDescriptor, XRImageTrackingSubsystem.Provider>.OnStop()
SubsystemWithProvider<XRImageTrackingSubsystem, XRImageTrackingSubsystemDescriptor, XRImageTrackingSubsystem.Provider>.OnDestroy()
SubsystemWithProvider<XRImageTrackingSubsystem, XRImageTrackingSubsystemDescriptor, XRImageTrackingSubsystem.Provider>.subsystemDescriptor
SubsystemWithProvider<XRImageTrackingSubsystem, XRImageTrackingSubsystemDescriptor, XRImageTrackingSubsystem.Provider>.provider
SubsystemWithProvider.Start()
SubsystemWithProvider.Stop()
SubsystemWithProvider.Destroy()
SubsystemWithProvider.OnDestroy()
SubsystemWithProvider.running
Namespace: UnityEngine.XR.ARSubsystems
Assembly: Unity.XR.ARSubsystems.dll
Syntax
public class XRImageTrackingSubsystem : TrackingSubsystem<XRTrackedImage, XRImageTrackingSubsystem, XRImageTrackingSubsystemDescriptor, XRImageTrackingSubsystem.Provider>, ISubsystem

Constructors

XRImageTrackingSubsystem()

Constructs a subsystem. Do not invoke directly; call Create on the XRImageTrackingSubsystemDescriptor instead.

Declaration
public XRImageTrackingSubsystem()

Properties

currentMaxNumberOfMovingImages

The current maximum number of moving images to track. This can be different from requestedMaxNumberOfMovingImages.

Declaration
public int currentMaxNumberOfMovingImages { get; }
Property Value
Type Description
int

imageLibrary

Get or set the reference image library. This is the set of images to look for in the environment.

Declaration
public RuntimeReferenceImageLibrary imageLibrary { get; set; }
Property Value
Type Description
RuntimeReferenceImageLibrary
Remarks

A RuntimeReferenceImageLibrary is created at runtime and can be modifiable (see MutableRuntimeReferenceImageLibrary). You can create a RuntimeReferenceImageLibrary from an XRReferenceImageLibrary using CreateRuntimeLibrary(XRReferenceImageLibrary).

Exceptions
Type Condition
ArgumentNullException

Thrown if the subsystem has been started, and you attempt to set the image library to null.
See Also

requestedMaxNumberOfMovingImages

The requested maximum number of moving images to track.

Declaration
public int requestedMaxNumberOfMovingImages { get; set; }
Property Value
Type Description
int
Exceptions
Type Condition
NotSupportedException

Thrown if the subsystem does not support tracking moving images. Check for support of this feature with supportsMovingImages.

Methods

CreateRuntimeLibrary(XRReferenceImageLibrary)

Creates a RuntimeReferenceImageLibrary from an existing XRReferenceImageLibrary, or an empty library if serializedLibrary is null. Use this to construct the runtime representation of an XRReferenceImageLibrary.

Declaration
public RuntimeReferenceImageLibrary CreateRuntimeLibrary(XRReferenceImageLibrary serializedLibrary)
Parameters
Type Name Description
XRReferenceImageLibrary serializedLibrary

An existing XRReferenceImageLibrary created at edit time, or null to create an empty image library.
Returns
Type Description
RuntimeReferenceImageLibrary

A new RuntimeReferenceImageLibrary representing the deserialized version of serializedLibrary or an empty library if serializedLibrary is null.
Remarks

If the subsystem supports runtime mutable libraries (see supportsMutableLibrary), then the returned library will be a MutableRuntimeReferenceImageLibrary.

See Also

GetChanges(Allocator)

Retrieve the changes in the state of tracked images (added, updated, and removed) since the last call to GetChanges.

Declaration
public override TrackableChanges<XRTrackedImage> GetChanges(Allocator allocator)
Parameters
Type Name Description
Allocator allocator

The allocator to use for the returned set of changes.
Returns
Type Description
TrackableChanges<XRTrackedImage>

The set of tracked image changes (added, updated, and removed) since the last call to this method.
Overrides

OnStart()

Starts the subsystem, that is, starts detecting images in the scene. imageLibrary must not be null.

Declaration
protected override void OnStart()
Overrides
UnityEngine.SubsystemsImplementation.SubsystemWithProvider<UnityEngine.XR.ARSubsystems.XRImageTrackingSubsystem, UnityEngine.XR.ARSubsystems.XRImageTrackingSubsystemDescriptor, UnityEngine.XR.ARSubsystems.XRImageTrackingSubsystem.Provider>.OnStart()
Exceptions
Type Condition
InvalidOperationException

Thrown if imageLibrary is null.

OnStop()

Stops the subsystem, that is, stops detecting and tracking images.

Declaration
protected override sealed void OnStop()
Overrides
UnityEngine.SubsystemsImplementation.SubsystemWithProvider<UnityEngine.XR.ARSubsystems.XRImageTrackingSubsystem, UnityEngine.XR.ARSubsystems.XRImageTrackingSubsystemDescriptor, UnityEngine.XR.ARSubsystems.XRImageTrackingSubsystem.Provider>.OnStop()

Implements

UnityEngine.ISubsystem