API Reference › core-geometry› Curve › UnionRegion

UnionRegion Class

  • A UnionRegion is a collection of other planar region types -- Loop and ParityRegion.
  • The composite is the union of the contained regions.
  • A point is "in" the composite if it is "in" one or more of the contained regions.

@see Curve Collections learning article.

Extends

Methods

Name Description
constructor(): UnionRegion Constructor -- initialize with no children  
announceToCurveProcessor(processor: RecursiveCurveProcessor, indexInParent: number = -1): void Dispatch to more strongly typed processor.announceUnionRegion(this, indexInParent)  
cloneEmptyPeer(): UnionRegion Return new empty UnionRegion  
cloneStroked(options?: StrokeOptions): UnionRegion Return structural clone with stroked primitives.  
dgnBoundaryType(): number Return the boundary type (5) of a corresponding MicroStation CurveVector  
dispatchToGeometryHandler(handler: GeometryHandler): any Second step of double dispatch: call handler.handleUnionRegion(this)  
getChild(i: number): undefined | Loop | ParityRegion Return a child identified by index.  
isSameGeometryClass(other: GeometryQuery): boolean Test if other is a UnionRegion  
tryAddChild(child: AnyCurve): boolean Try to add a child (by capturing it).  
create(...data: Loop | ParityRegion[]): UnionRegion Static Create a UnionRegion by capturing the given regions as children.  

Inherited methods

Name Inherited from Description
allTangents(spacePoint: Point3d, options?: TangentOptions): undefined | CurveLocationDetail[] Inherited CurveCollection Return all points P on the contained curves such that the line containing spacePoint and P is tangent to the
checkForNonLinearPrimitives(): boolean Inherited CurveCollection Return true if the curve collection has any primitives other than LineSegment3d and LineString3d
clone(): CurveCollection Inherited CurveCollection Return a deep copy.
cloneTransformed(transform: Transform): undefined | CurveCollection Inherited CurveCollection Create a deep copy of transformed curves.
cloneWithExpandedLineStrings(): CurveCollection Inherited CurveCollection Create a deep copy with all linestrings broken down into multiple LineSegment3d.
closestPoint(spacePoint: Point3d, _extend: VariantCurveExtendParameter = false, result?: CurveLocationDetail): undefined | CurveLocationDetail Inherited CurveCollection Return the closest point on the contained curves.
closestTangent(spacePoint: Point3d, options?: TangentOptions): undefined | CurveLocationDetail Inherited CurveCollection Return the point P on the contained curves such that the line containing spacePoint and P is tangent to the
collectCurvePrimitives(collectorArray?: CurvePrimitive[], smallestPossiblePrimitives: boolean = false, explodeLineStrings: boolean = false): CurvePrimitive[] Inherited CurveCollection Return an array containing all CurvePrimitives in the instance.
emitTangents(spacePoint: Point3d, announceTangent: (tangent: CurveLocationDetail) => any, options?: TangentOptions): void Inherited CurveCollection Announce all points P on the contained curves such that the line containing spacePoint and P is tangent to
extendRange(rangeToExtend: Range3d, transform?: Transform): void Inherited CurveCollection Extend (increase) the given range as needed to encompass all curves in the curve collection.
findParentOfDescendant(descendant: AnyCurve): undefined | CurveCollection Inherited CurveCollection Return the immediate parent of the input curve in the instance, or undefined if it is not a descendant.
isAlmostEqual(other: GeometryQuery): boolean Inherited CurveCollection Test for exact structure and nearly identical geometry.
isAnyRegion(): this is AnyRegion Inherited CurveCollection Type guard for AnyRegion
isLoop(): this is Loop Inherited CurveCollection Type guard for Loop
isPath(): this is Path Inherited CurveCollection Type guard for Path
maxGap(): number Inherited CurveCollection Return the max gap between adjacent primitives in Path and Loop collections.
projectedParameterRange(ray: Vector3d | Ray3d, lowHigh?: Range1d): undefined | Range1d Inherited CurveCollection Project instance geometry (via dispatch) onto the given ray, and return the extreme fractional parameters
range(transform?: Transform, result?: Range3d): Range3d Inherited CurveCollection Return the range of the entire GeometryQuery tree.
reverseInPlace(): void Inherited CurveCollection Reverse the collection's data so that each child curve's fractional stroking moves in the opposite direction.
sumLengths(): number Inherited CurveCollection Return the sum of the lengths of all contained curves.
tryTransformInPlace(transform: Transform): boolean Inherited CurveCollection Apply transform recursively to children
tryTranslateInPlace(dx: number, dy: number = 0.0, dz: number = 0.0): boolean Inherited CurveCollection Try to move the geometry by dx,dy,dz.
areAlmostEqual(a: GeometryQuery, b: GeometryQuery): boolean Static Inherited CurveCollection Apply instance method isAlmostEqual if both are defined.
createCurveLocationDetailOnAnyCurvePrimitive(source: GeometryQuery, fraction: number = 0.5): undefined | CurveLocationDetail Static Inherited CurveCollection Find any CurvePrimitive in the source and evaluate it at the given fraction.

Properties

Name Type Description
_children Protected Loop | ParityRegion[] Collection of Loop and ParityRegion children.  
children Accessor ReadOnly Loop | ParityRegion[] Return the array of regions  
curveCollectionType Readonly "unionRegion" String name for schema properties  

Inherited properties

Name Type Inherited from Description
geometryCategory Readonly Inherited "curveCollection" CurveCollection String name for schema properties
isAnyRegionType Accessor Inherited ReadOnly boolean CurveCollection Return true for planar region types:
* Loop
* ParityRegion
* UnionRegion
isClosedPath Accessor Inherited ReadOnly boolean CurveCollection Return true for a single-loop planar region type, i.e. Loop.
* This is NOT a test for physical closure of a Path.
isInner Inherited boolean CurveCollection Flag for inner loop status.
isOpenPath Accessor Inherited ReadOnly boolean CurveCollection Return true for a Path, i.e. a chain of curves joined head-to-tail

Defined in

Last Updated: 24 October, 2025