Anchor

public class Anchor

Describes a fixed location and orientation in the real world. To stay at a fixed location in physical space, the numerical description of this position will update as ARCore's understanding of the space improves.

Use getPose() to get the current numerical location of this anchor. This location may change any time Session.update() is called, but will never spontaneously change.

mathematically:
point_world = anchor.getPose().transformPoint(point_local);
point_world = anchor.getPose().toMatrix() * point_local;

anchor.getPose().toMatrix(...) provides a matrix appropriate for composing with the view and projection matrices when rendering an object at this anchor's location.

Anchors are hashable and may for example be used as keys in HashMaps.

Anchors incur ongoing processing overhead within ARCore. To release unneeded anchors use detach().

Nested Classes

enum

Anchor.CloudAnchorState

Enumeration of all Cloud Anchor States

Public Methods

void	detach() Detaches this Anchor from its Trackable removes it from the Session.
boolean	equals(Object obj) Indicates whether some other object is an Anchor referencing the same logical anchor as this one.
String	getCloudAnchorId() Gets the current cloud anchor ID for this anchor.
Anchor.CloudAnchorState	getCloudAnchorState() Gets the current cloud anchor state of this anchor.
Pose	getPose() Returns the pose of the anchor in the world coordinate space.
TrackingState	getTrackingState() Returns the current state of the pose of this anchor.
int	hashCode() Returns a hash code value for the object.

Inherited Methods

From class java.lang.Object

Object	clone()
boolean	equals(Object arg0)
void	finalize()
final Class<?>	getClass()
int	hashCode()
final void	notify()
final void	notifyAll()
String	toString()
final void	wait(long arg0, int arg1)
final void	wait(long arg0)
final void	wait()

Public Methods

public void detach ()

Detaches this Anchor from its Trackable removes it from the Session. After calling, getTrackingState() will return TrackingState.STOPPED and ARCore will no longer update this Anchor's pose or return it from Session.getAllAnchors().

public boolean equals (Object obj)

Indicates whether some other object is an Anchor referencing the same logical anchor as this one.

Parameters

obj	the reference object with which to compare.

Returns

• true if this object is the same as the obj argument; false otherwise.

See Also

• hashCode()
• HashMap

public String getCloudAnchorId ()

Gets the current cloud anchor ID for this anchor. Returns an empty string if getCloudAnchorState() returns Anchor.CloudAnchorState.TASK_IN_PROGRESS or Anchor.CloudAnchorState.NONE.

public Anchor.CloudAnchorState getCloudAnchorState ()

Gets the current cloud anchor state of this anchor.

public Pose getPose ()

Returns the pose of the anchor in the world coordinate space. This pose may change each time Session.update() is called. This pose should only be used for rendering if getTrackingState() returns TrackingState.TRACKING.

public TrackingState getTrackingState ()

Returns the current state of the pose of this anchor. If this state is anything other than TrackingState.TRACKING the pose should not be considered useful.

Note: Starting in ARCore 1.12, changing the active camera config using Session.setCameraConfig(CameraConfig) may cause the tracking state on certain devices to become permanently PAUSED. For consistent behavior across all supported devices, release any previously created anchors when setting a new camera config.

public int hashCode ()

Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.

Returns

• a hash code value for this object.

See Also

• equals(Object)