Class AnchorManager

Encapsulation of spongy world (raw input) state. Its primary duty is the creation and maintenance of the graph of (spongy) anchors built up over the space traversed by the camera.

Inheritance

Object

AnchorManager

AnchorManagerARCore

AnchorManagerNull

AnchorManagerWSA

Implements

IAnchorManager

IDisposable

Inherited Members

Object.ToString()

Object.Equals(Object)

Object.Equals(Object, Object)

Object.ReferenceEquals(Object, Object)

Object.GetHashCode()

Object.GetType()

Object.MemberwiseClone()

Namespace: Microsoft.MixedReality.WorldLocking.Core

Assembly: cs.temp.dll.dll

Syntax

public abstract class AnchorManager : IAnchorManager, IDisposable

Remarks

Anchor and Edge creation algorithm:

Goal: a simple and robust algorithm that guarantees an even distribution of anchors, fully connected by edges between nearest neighbors with a minimum of redundant edges

For simplicity, the algorithm should be stateless between time steps

Rules

• two parameters define spheres MIN and MAX around current position
• whenever MIN does not contain any anchors, a new anchor is created
• when a new anchor is created is is linked by edges to all anchors within MAX
• the MAX radius is 20cm larger than MIN radius which would require 12 m/s beyond world record sprinting speed to cover in one frame
• whenever MIN contains more than one anchor, the anchor closest to current position is connected to all others within MIN

Constructors

AnchorManager(IPlugin, IHeadPoseTracker)

Set up an anchor manager.

Declaration

public AnchorManager(IPlugin plugin, IHeadPoseTracker headTracker)

Parameters

Type	Name	Description
IPlugin	plugin	The engine interface to update with the current anchor graph.
IHeadPoseTracker	headTracker

Properties

AnchorFromSpongy

Declaration

public virtual Pose AnchorFromSpongy { get; }

Property Value

Type	Description
Pose

ErrorStatus

Error string for last error, cleared at beginning of each update.

Declaration

public string ErrorStatus { get; }

Property Value

Type	Description
String

MaxAnchorEdgeLength

Maximum distance between two anchors to create an edge between them.

Declaration

public float MaxAnchorEdgeLength { get; set; }

Property Value

Type	Description
Single

Remarks

Note that the MaxAnchorEdgeLength should be longer than the MinAnchorDistance, or else anchors will not be connected into a graph as they are created.

MaxLocalAnchors

Maximum number of local anchors in the internal anchor graph.

Declaration

public int MaxLocalAnchors { get; set; }

Property Value

Type	Description
Int32

Remarks

Zero or negative means unlimited anchors.

MinNewAnchorDistance

Minimum distance of head to nearest anchor to create a new anchor.

Declaration

public float MinNewAnchorDistance { get; set; }

Property Value

Type	Description
Single

NumAnchors

Return the current number of spongy anchors.

Declaration

public int NumAnchors { get; }

Property Value

Type	Description
Int32

NumEdges

The number of edges connecting spongy anchors.

Declaration

public int NumEdges { get; }

Property Value

Type	Description
Int32

SpongyAnchors

Declaration

public List<AnchorManager.SpongyAnchorWithId> SpongyAnchors { get; }

Property Value

Type	Description
List<AnchorManager.SpongyAnchorWithId>

SupportsPersistence

Whether the underlying anchors can be locally persisted and reloaded.

Declaration

public abstract bool SupportsPersistence { get; }

Property Value

Type	Description
Boolean

TrackingStartDelayTime

Declaration

protected abstract float TrackingStartDelayTime { get; }

Property Value

Type	Description
Single

Methods

CreateAnchor(AnchorId, Transform, Pose)

Platform dependent instantiation of a local anchor at given position.

Declaration

protected abstract SpongyAnchor CreateAnchor(AnchorId id, Transform parent, Pose initialPose)

Parameters

Type	Name	Description
AnchorId	id	Anchor id to give new anchor.
Transform	parent	Object to hang anchor off of.
Pose	initialPose	Pose for the anchor.

Returns

Type	Description
SpongyAnchor	The new anchor

DebugLogExtra(String)

Declaration

[Conditional("WLT_EXTRA_LOGGING")]
protected static void DebugLogExtra(string message)

Parameters

Type	Name	Description
String	message

DebugLogSetup(String)

Declaration

[Conditional("WLT_LOG_SETUP")]
protected static void DebugLogSetup(string message)

Parameters

Type	Name	Description
String	message

DestroyAnchor(AnchorId, SpongyAnchor)

Platform dependent disposal of local anchors.

Declaration

protected abstract SpongyAnchor DestroyAnchor(AnchorId id, SpongyAnchor spongyAnchor)

Parameters

Type	Name	Description
AnchorId	id	The id of the anchor to destroy.
SpongyAnchor	spongyAnchor	Reference to the anchor to destroy.

Returns

Type	Description
SpongyAnchor	Null

Remarks

The id is used to delete from any stored lists. If the SpongyAnchor hasn't been added to any lists (is still initializing), id can be AnchorId.Invalid.

Dispose()

Explicit dispose to release resources.

Declaration

public void Dispose()

Finalize()

GC release of resources.

Declaration

protected void Finalize()

IsTracking()

Declaration

protected abstract bool IsTracking()

Returns

Type	Description
Boolean

LoadAnchors()

Load the spongy anchors from persistent storage

Declaration

public async Task LoadAnchors()

Returns

Type	Description
Task

Remarks

The set of spongy anchors loaded by this routine is defined by the frozen anchors previously loaded into the plugin.

Likewise, when a spongy anchor fails to load, this routine will delete its frozen counterpart from the plugin.

LoadAnchors(IPlugin, AnchorId, Transform, List<AnchorManager.SpongyAnchorWithId>)

Declaration

protected virtual async Task LoadAnchors(IPlugin plugin, AnchorId firstId, Transform parent, List<AnchorManager.SpongyAnchorWithId> spongyAnchors)

Parameters

Type	Name	Description
IPlugin	plugin
AnchorId	firstId
Transform	parent
List<AnchorManager.SpongyAnchorWithId>	spongyAnchors

Returns

Type	Description
Task

RemoveSpongyAnchorById(AnchorId)

Remove all internal references to the anchor identified.

Declaration

protected void RemoveSpongyAnchorById(AnchorId id)

Parameters

Type	Name	Description
AnchorId	id	The anchor to forget.

Remarks

It is not an error to pass in AnchorId.Unknown or AnchorId.Invalid, although neither will have any effect. It is an error to pass in a valid id which doesn't correspond to a valid anchor. This function should be called as part of any IAnchorManager's implementation of DestroyAnchor().

Reset()

Delete all spongy anchor objects and reset internal state

Declaration

public void Reset()

SaveAnchors()

Save the spongy anchors to persistent storage

Declaration

public async Task SaveAnchors()

Returns

Type	Description
Task

SaveAnchors(List<AnchorManager.SpongyAnchorWithId>)

Declaration

protected virtual async Task SaveAnchors(List<AnchorManager.SpongyAnchorWithId> spongyAnchors)

Parameters

Type	Name	Description
List<AnchorManager.SpongyAnchorWithId>	spongyAnchors

Returns

Type	Description
Task

Update()

Create missing spongy anchors/edges and feed plugin with up-to-date input

Declaration

public virtual bool Update()

Returns

Type	Description
Boolean	Boolean: Has the plugin received input to provide an adjustment?

Implements

IAnchorManager

System.IDisposable