Class ARTrackedImageManager

A manager for ARTrackedImages. Uses the XRImageTrackingSubsystem to recognize and track 2D images in the physical environment.

Inheritance
Object
SubsystemLifecycleManager<XRImageTrackingSubsystem, XRImageTrackingSubsystemDescriptor>
ARTrackableManager<XRImageTrackingSubsystem, XRImageTrackingSubsystemDescriptor, XRTrackedImage, ARTrackedImage>
ARTrackedImageManager
Inherited Members
Namespace: UnityEngine.XR.ARFoundation
Syntax
public sealed class ARTrackedImageManager : ARTrackableManager<XRImageTrackingSubsystem, XRImageTrackingSubsystemDescriptor, XRTrackedImage, ARTrackedImage>

Properties

gameObjectName

The name to be used for the GameObject whenever a new image is detected.

Declaration
protected override string gameObjectName { get; }
Property Value
Type Description
String
Overrides
UnityEngine.XR.ARFoundation.ARTrackableManager<XRImageTrackingSubsystem, XRImageTrackingSubsystemDescriptor, XRTrackedImage, UnityEngine.XR.ARFoundation.ARTrackedImage>.gameObjectName

maxNumberOfMovingImages

The maximum number of moving images to track in realtime. Support may vary between devices and providers. Check for support at runtime with .SubsystemDescriptor.supportsMovingImages.

Declaration
public int maxNumberOfMovingImages { get; set; }
Property Value
Type Description
Int32
Exceptions
Type Condition
InvalidOperationException

Thrown if the subsystem does not support moving images.

referenceLibrary

Get or set the reference image library, the set of images to search for in the physical environment.

Declaration
public IReferenceImageLibrary referenceLibrary { get; set; }
Property Value
Type Description
IReferenceImageLibrary
Remarks

An IReferenceImageLibrary can be either an XRReferenceImageLibrary or a RuntimeReferenceImageLibrary. XRReferenceImageLibrarys can only be constructed at edit-time and are immutable at runtime. A RuntimeReferenceImageLibrary is the runtime representation of a XRReferenceImageLibrary and may be mutable at runtime (see MutableRuntimeReferenceImageLibrary).

Exceptions
Type Condition
InvalidOperationException

Thrown if the referenceLibrary is set to null while image tracking is enabled.

trackedImagePrefab

If not null, instantiates this prefab for each detected image.

Declaration
public GameObject trackedImagePrefab { get; set; }
Property Value
Type Description
GameObject

Methods

CreateRuntimeLibrary(XRReferenceImageLibrary)

Creates a UnityEngine.XR.ARSubsystems.RuntimeReferenceImageLibrary from an existing UnityEngine.XR.ARSubsystems.XRReferenceImageLibrary or an empty library if serializedLibrary is null. Use this to construct reference image libraries at runtime. If the library is of type MutableRuntimeReferenceImageLibrary, it is modifiable at runtime.

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

An existing XRReferenceImageLibrary, or null to create an empty mutable image library.
Returns
Type Description
RuntimeReferenceImageLibrary

A new RuntimeReferenceImageLibrary representing the deserialized version of serializedLibraryor an empty library if serializedLibrary is null.
Exceptions
Type Condition
NotSupportedException

Thrown if there is no subsystem. This usually means image tracking is not supported.

GetPrefab()

Declaration
protected override GameObject GetPrefab()
Returns
Type Description
GameObject
Overrides
UnityEngine.XR.ARFoundation.ARTrackableManager<XRImageTrackingSubsystem, XRImageTrackingSubsystemDescriptor, XRTrackedImage, UnityEngine.XR.ARFoundation.ARTrackedImage>.GetPrefab()

OnAfterSetSessionRelativeData(ARTrackedImage, XRTrackedImage)

Declaration
protected override void OnAfterSetSessionRelativeData(ARTrackedImage image, XRTrackedImage sessionRelativeData)
Parameters
Type Name Description
ARTrackedImage image
XRTrackedImage sessionRelativeData
Overrides
UnityEngine.XR.ARFoundation.ARTrackableManager<XRImageTrackingSubsystem, XRImageTrackingSubsystemDescriptor, XRTrackedImage, UnityEngine.XR.ARFoundation.ARTrackedImage>.OnAfterSetSessionRelativeData(UnityEngine.XR.ARFoundation.ARTrackedImage, XRTrackedImage)

OnBeforeStart()

Sets the image library on the subsystem before Start() is called on the XRImageTrackingSubsystem.

Declaration
protected override void OnBeforeStart()
Overrides
UnityEngine.XR.ARFoundation.SubsystemLifecycleManager<XRImageTrackingSubsystem, XRImageTrackingSubsystemDescriptor>.OnBeforeStart()

OnTrackablesChanged(List<ARTrackedImage>, List<ARTrackedImage>, List<ARTrackedImage>)

Invokes the trackedImagesChanged event.

Declaration
protected override void OnTrackablesChanged(List<ARTrackedImage> added, List<ARTrackedImage> updated, List<ARTrackedImage> removed)
Parameters
Type Name Description
List<ARTrackedImage> added

A list of images added this frame.
List<ARTrackedImage> updated

A list of images updated this frame.
List<ARTrackedImage> removed

A list of images removed this frame.
Overrides
UnityEngine.XR.ARFoundation.ARTrackableManager<XRImageTrackingSubsystem, XRImageTrackingSubsystemDescriptor, XRTrackedImage, UnityEngine.XR.ARFoundation.ARTrackedImage>.OnTrackablesChanged(System.Collections.Generic.List<UnityEngine.XR.ARFoundation.ARTrackedImage>, System.Collections.Generic.List<UnityEngine.XR.ARFoundation.ARTrackedImage>, System.Collections.Generic.List<UnityEngine.XR.ARFoundation.ARTrackedImage>)

Events

trackedImagesChanged

Invoked once per frame with information about the ARTrackedImages that have changed, i.e., been added, updated, or removed. This happens just before ARTrackedImages are destroyed, so you can set ARTrackedImage.destroyOnRemoval to false from this event to suppress this behavior.

Declaration
public event Action<ARTrackedImagesChangedEventArgs> trackedImagesChanged
Event Type
Type Description
Action<ARTrackedImagesChangedEventArgs>