Represents an anchor in the Mixed Reality Utility Kit. This combines an Unreal actor with the scene anchor. The actor is placed at the position of the anchor and the actor's rotation is set to match the rotation of the anchor. Provides functions to check if a position is inside the volume or plane of the anchor, raycast against the anchor, etc...

See Also

https://developer.oculus.com/documentation/unreal/unreal-spatial-anchors/ for more information about anchors in the Mixed Reality Utility Kit.

Fields

FOculusXRUInt64 SpaceHandle[Get]

The space handle of this anchor

FOculusXRUUID AnchorUUID[Get]

The anchors UUID

TArray< FString > SemanticClassifications[Get]

The semantic classification of the anchor, also sometimes refered to as labels for short. This can be for example FLOOR, COUCH, TABLE, SCREEN, BED, LAMP, etc...

FBox2D PlaneBounds[Get]

If the anchor has a plane attached to it, this represents the bounds of that plane in local coordinate space.

TArray< FVector2D > PlaneBoundary2D[Get]

If the anchor has a plane attached to it, this represents the boundary of it in local coordinate space. For rectangular boundaries this will be the same as the PlaneBounds.

FBox VolumeBounds[Get]

If the anchor has a volume attached to it, this represents the bounds of that volume in local coordinate space.

TObjectPtr< UProceduralMeshComponent > ProceduralMeshComponent[Get]

Procedural mesh that is generated from the anchor geometry.

TObjectPtr< AMRUKAnchor > ParentAnchor[Get]

Pointer to the parent anchor, e.g. if this is a door or window frame the parent will be a wall. If this is a screen it could have a desk parent.

TArray< TObjectPtr< AMRUKAnchor > > ChildAnchors[Get]

Array of all children attached to it, e.g. if this is a wall, it could have an array of door/window frames. If this is a desk it could have an array of screens on it.

TObjectPtr< AMRUKRoom > Room[Get]

The room this anchor is placed in.

TArray< FVector > SceneMeshPositions[Get]

Positions of the global mesh. Only populated if the anchor is has the label GLOABL_MESH and the option UseSharedLibraryForAnchorLoading is set to true.

TArray< int > SceneMeshIndices[Get]

Indices of the global mesh. Only populated if the anchor is has the label GLOABL_MESH and the option UseSharedLibraryForAnchorLoading is set to true.

Member Functions

bool IsPositionInBoundary

( const FVector2D & Position )

Check if a 2D position is within the boundary of the plane. The position should be in the local coordinate system NOT world coordinates.

FVector GenerateRandomPositionOnPlane ( )

Generate a uniform random position within the boundary of the plane.

Returns

The random position in local coordinate space.

FVector GenerateRandomPositionOnPlaneFromStream

( const FRandomStream & RandomStream )

Generate a uniform random position within the boundary of the plane from a random stream.

Parameters

RandomStream

A random generator used to generate the position on the plane.

Returns

The random position in local coordinate space.

bool Raycast

( const FVector & Origin,

const FVector & Direction,

float MaxDist,

FMRUKHit & OutHit,

UPARAM(meta=(Bitmask, BitmaskEnum="EMRUKComponentType")) int32 ComponentTypes )

Cast a ray and return the closest hit against the volume and plane bounds.

Parameters

Origin

Origin The origin of the ray.

Direction

Direction The direction of the ray.

MaxDist

The maximum distance the ray should travel.

OutHit

The closest hit.

ComponentTypes

The component types to include in the raycast.

Returns

Whether the ray hit anything

bool RaycastAll

( const FVector & Origin,

const FVector & Direction,

float MaxDist,

TArray< FMRUKHit > & OutHits,

UPARAM(meta=(Bitmask, BitmaskEnum="EMRUKComponentType")) int32 ComponentTypes )

Cast a ray and collect hits against the volume and plane bounds. The order of the hits in the array is not specified.

Parameters

Origin

Origin The origin of the ray.

Direction

Direction The direction of the ray.

MaxDist

The maximum distance the ray should travel.

OutHits

The hits the ray collected.

ComponentTypes

The component types to include in the raycast.

Returns

Whether the ray hit anything

void AttachProceduralMesh

( TArray< FMRUKPlaneUV > PlaneUVAdjustments,

const TArray< FString > & CutHoleLabels,

bool GenerateCollision,

UMaterialInterface * ProceduralMaterial )

Attach a procedural mesh to the anchor. The mesh will match the size, position and shape of the volume and/or plane if they are set.

Parameters

PlaneUVAdjustments

Scale and offset to apply to the UV texture coordinates. If more than one is specified then multiple UV texture coordinates are created (up to 4) and adjustments applied to each. This can be left empty in which case a single set of UV texture coordinates are created in the range 0 to 1 for the plane.

CutHoleLabels

Labels for which the generated mesh should have holes. Only works with planes.

GenerateCollision

Whether to generate collision geometry or not

ProceduralMaterial

Material to use on the procedural generated mesh.

void GenerateProceduralAnchorMesh

( UProceduralMeshComponent * ProceduralMesh,

const TArray< FMRUKPlaneUV > & PlaneUVAdjustments,

const TArray< FString > & CutHoleLabels,

bool PreferVolume,

bool GenerateCollision,

double Offset )

Generate a procedural mesh for the anchor. The mesh will match the size, position and shape of the volume and/or plane if they are set.

Parameters

ProceduralMesh

The procedural mesh component that should be used to store the generated mesh.

PlaneUVAdjustments

CutHoleLabels

Labels for which the generated mesh should have holes. Only works with planes.

GenerateCollision

Whether to generate collision geometry or not

Offset

A offset to make the procedural mesh slightly bigger or smaller than the anchors volume/plane.

bool HasLabel

( const FString & Label )

Check if the anchor has the given label.

Parameters

Label

The label to check.

Returns

Whether the anchor has the given label.

bool HasAnyLabel

( const TArray< FString > & Labels )

Check if the anchor has any of the given labels.

Parameters

Labels

The labels to check.

Returns

Whether the anchor has any of the given labels.

bool PassesLabelFilter

( const FMRUKLabelFilter & LabelFilter )

Check if the anchor passes the given label filter

Parameters

LabelFilter

The labels to check.

Returns

Whether the anchor has any of the given labels.

double GetClosestSurfacePosition

( const FVector & TestPosition,

FVector & OutSurfacePosition )

Calculate the closest surface position on this anchor.

Parameters

TestPosition

The position in world space for which the closes surface position should be obtained.

OutSurfacePosition

The closest surface position

Returns

The distance between TestPosition and OutSurfacePosition

bool IsPositionInVolumeBounds

( const FVector & Position,

bool TestVerticalBounds,

double Tolerance )

Checks if the given position is on or inside the volume bounds. Floor, ceiling and wall anchors will be excluded from the search.

Parameters

Position

The position in world space to check

TestVerticalBounds

Whether the vertical bounds should be checked or not

Tolerance

Tolerance

Returns

The anchor the WorldPosition is in. A null pointer otherwise.

FVector GetFacingDirection ( )

Gets a natural “forward” direction for anchors; for planes, this is always Z-forward. For volumes, it’s the X/Y cardinal axis that aligns best with the normal of the closest wall.

Returns

The forward facing direction.

AActor * SpawnInterior

( const TSubclassOf< class AActor > & ActorClass,

bool MatchAspectRatio,

bool CalculateFacingDirection,

EMRUKSpawnerScalingMode ScalingMode )

Spawn a mesh on the position of this anchor. The actor should have Z as up, Y as right and X as forward.

Parameters

ActorClass

The Class to spawn at the anchors position.

MatchAspectRatio