API Reference > geometry-core > Curve > LineString3d LineString3d Class A LineString3d (sometimes called a PolyLine) is a sequence of xyz coordinates that are to be joined by line segments. The point coordinates are stored in a GrowableXYZArray, not as full point objects The parameterization of "fraction along" is In a linestring with N segments (i.e. N+1 points), each segment (regardless of physical length) occupies the same fraction (1/N) of the 0-to-1 fraction space. Within segment i, the fraction interval i/N to (i+1)/N is mapped proportionally to the segment Note that this fraction is therefore NOT fraction of true distance along. Use moveSignedDistanceFromFraction to do true-length evaluations. Extends CurvePrimitive Implements BeJSONFunctions Methods Name Description constructor(): LineString3d Protected addClosurePoint(): void If the linestring is not already closed, add a closure point. addDerivative(vector: Vector3d): void Append a derivative to the derivative array addFraction(fraction: number): void Append a fraction to the fractions array. addMappedStrokesToLineString3D(map: StrokeCountMap, destLinestring: LineString3d): number evaluate strokes at fractions indicated in a StrokeCountMap. addPoint(point: Point3d): void Add a point to the linestring. addPointXYZ(x: number, y: number, z: number = 0): void Add a point to the linestring. addPoints(...points: any[]): void Add points to the linestring. addSteppedPoints(source: GrowableXYZArray, pointIndex0: number, step: number, numAdd: number): void Add points accessed by index in a GrowableXYZArray, with a specified index step. addSurfaceNormal(vector: Vector3d): void Append a surface normal to the surface normal array. addUVParam(uvParam: XAndY): void Append a uv coordinate to the uvParams array addUVParamAsUV(u: number, v: number): void Append a uv coordinate to the uvParams array announceClipIntervals(clipper: Clipper, announce?: AnnounceNumberNumberCurvePrimitive): boolean Find intervals of this CurvePrimitive that are interior to a clipper appendFractionToPoint(curve: CurvePrimitive, fraction: number): void Append a suitable evaluation of a curve .. appendFractionalStrokePoints(curve: CurvePrimitive, numStrokes: number, fraction0: number = 0, fraction1: number = 1, include01: boolean = true): void Evaluate a curve at uniform fractions. appendInterpolatedStrokePoints(numStrokes: number, point0: Point3d, point1: Point3d, include01: boolean): void Append points constructed as interpolation between two points. appendPlaneIntersectionPoints(plane: PlaneAltitudeEvaluator, result: CurveLocationDetail[]): number find intersections with a plane. appendStrokePoint(point: Point3d, fraction?: number): void Append (clone of) one point. clear(): void clear all array data: clone(): LineString3d Return a clone of this linestring. clonePartialCurve(fractionA: number, fractionB: number): CurvePrimitive | undefined Return (if possible) a LineString which is a portion of this curve. cloneTransformed(transform: Transform): CurvePrimitive Clone this linestring and apply the transform to the clone points. closestPoint(spacePoint: Point3d, extend: VariantCurveExtendParameter, result?: CurveLocationDetail): CurveLocationDetail Find the point on the linestring (including its segment interiors) that is closest to spacePoint. computeAndAttachRecursiveStrokeCounts(options?: StrokeOptions, parentStrokeMap?: StrokeCountMap): void Compute individual segment stroke counts. computeStrokeCountForOptions(options?: StrokeOptions): number return the stroke count required for given options. computeUVFromXYZTransform(transform: Transform): void Compute uvParams array as (xy parts of) a linear transform of the xyz coordinates curveLength(): number Sum the lengths of segments within the linestring curveLengthBetweenFractions(fraction0: number, fraction1: number): number Sum the lengths of segments between fractional positions on a linestring. derivativeAt(i: number, result?: Vector3d): Vector3d | undefined If i is a valid index, return that stored derivative vector. dispatchToGeometryHandler(handler: GeometryHandler): any Second step of double dispatch: call handler.handleLineString3d(this) emitStrokableParts(handler: IStrokeHandler, options?: StrokeOptions): void Emit strokable parts of the curve to a caller-supplied handler. emitStrokes(dest: LineString3d, options?: StrokeOptions): void Emit strokes to caller-supplied linestring endPoint(): Point3d evaluate the end point of the linestring. ensureEmptyDerivatives(): GrowableXYZArray Ensure that the surfaceNormals array exists with no points but at least the capacity of the point array. ensureEmptyFractions(): GrowableFloat64Array Ensure that the fraction array exists with no fractions but at least the capacity of the point array. ensureEmptyNormalIndices(): GrowableFloat64Array Ensure that the surfaceNormals array exists with no points but at least the capacity of the point array. ensureEmptyPointIndices(): GrowableFloat64Array Ensure that the surfaceNormals array exists with no points but at least the capacity of the point array. ensureEmptySurfaceNormals(): GrowableXYZArray Ensure that the surfaceNormals array exists with no points but at least the capacity of the point array. ensureEmptyUVIndices(): GrowableFloat64Array Ensure that the surfaceNormals array exists with no points but at least the capacity of the point array. ensureEmptyUVParams(): GrowableXYArray Ensure that the parameter array exists with no points but at least the capacity of the point array. extendRange(rangeToExtend: Range3d, transform?: Transform): void Extend rangeToExtend to include all points of this linestring. fractionToFrenetFrame(fraction: number, result?: Transform): Transform Return a frenet frame, using nearby points to estimate a plane. fractionToPoint(fraction: number, result?: Point3d): Point3d Evaluate a point a fractional position along this linestring. fractionToPointAnd2Derivatives(fraction: number, result?: Plane3dByOriginAndVectors): Plane3dByOriginAndVectors Return point and derivative at fraction, with 000 second derivative. fractionToPointAndDerivative(fraction: number, result?: Ray3d): Ray3d Evaluate a point a fractional position and derivative with respect to fraction along this linestring. getIndexedSegment(index: number): LineSegment3d | undefined Return (if possible) a specific segment of the linestring isAlmostEqual(other: GeometryQuery): boolean Test if each point of this linestring isAlmostEqual with corresponding point in other. isInPlane(plane: Plane3dByOriginAndUnitNormal): boolean Test if all points of the linestring are in a plane. isSameGeometryClass(other: GeometryQuery): boolean test if other is an instance of LineString3d moveSignedDistanceFromFraction(startFraction: number, signedDistance: number, allowExtension: false, result?: CurveLocationDetail): CurveLocationDetail * Implementation of CurvePrimitive.moveSignedDistanceFromFraction. numPoints(): number Return the number of points in this linestring. pointAt(i: number, result?: Point3d): Point3d | undefined If i is a valid index, return that point. popPoint(): void Eliminate (but do not return!!) the final point of the linestring quickLength(): number sum lengths of segments in the linestring. quickUnitNormal(result?: Vector3d): Vector3d | undefined compute and normalize cross product among 3 points on the linestring. reverseInPlace(): void Reverse the points within the linestring. segmentIndexAndLocalFractionToGlobalFraction(index: number, localFraction: number): number Convert a segment index and local fraction to a global fraction. setFrom(other: LineString3d): void Copy coordinate data from another linestring. setFromJSON(json?: any): void Set point coordinates from a json array, e.g. startPoint(): Point3d evaluate the start point of the linestring. surfaceNormalAt(i: number, result?: Vector3d): Vector3d | undefined If i is a valid index, return that stored surfaceNormal vector. toJSON(): any Convert an LineString3d to a JSON object. tryTransformInPlace(transform: Transform): boolean Apply transform to each point of this linestring. vectorBetween(i: number, j: number, result?: Vector3d): Vector3d | undefined If i and j are both valid indices, return the vector from point i to point j create(...points: any[]): LineString3d Static Create a linestring, using flex length arg list and any typical combination of points such as createArrayOfLineString3d(data: MultiLineStringDataVariant): LineString3d[] Static This method name is deprecated. Deprecated createArrayOfLineString3dFromVariantData(data: MultiLineStringDataVariant): LineString3d[] Static convert variant point data to a single level array of linestrings. createCapture(points: GrowableXYZArray): LineString3d Static Create a linestring, capturing the given GrowableXYZArray as the points. createFloat64Array(xyzData: Float64Array): LineString3d Static Create a LineString3d from xyz coordinates packed in a Float64Array createForStrokes(capacity: number = 0, options: StrokeOptions | undefined): LineString3d Static * options.needParams triggers creation of fraction array and uvParams array. createIndexedPoints(points: Point3d[], index: number[], addClosure: boolean = false): LineString3d Static Create a linestring, taking points at specified indices from an array of points. createPoints(points: Point3d[]): LineString3d Static Create a linestring from an array of points. createRectangleXY(point0: Point3d, ax: number, ay: number, closed: boolean = true): LineString3d Static Create the linestring for a rectangle parallel to the xy plane. createRegularPolygonXY(center: Point3d, edgeCount: number, radius: number, radiusToVertices: boolean = true): LineString3d Static Create a regular polygon centered createXY(points: XAndY[], z: number, enforceClosure: boolean = false): LineString3d Static Create a linestring from XAndY points, with a specified z applied to all. fromJSON(json?: any): LineString3d Static construct a new linestring. Inherited methods Name Inherited from Description collectCurvePrimitives(collectorArray?: CurvePrimitive[], smallestPossiblePrimitives: boolean = false): CurvePrimitive[] CurvePrimitive Return an array containing only the curve primitives. collectCurvePrimitivesGo(collectorArray: CurvePrimitive[], _smallestPossiblePrimitives: boolean): void CurvePrimitive Return an array containing only the curve primitives. curveLengthWithFixedIntervalCountQuadrature(fraction0: number, fraction1: number, numInterval: number, numGauss: number = 5): number CurvePrimitive * Run an integration (with a default gaussian quadrature) with a fixed fractional step fractionAndDistanceToPointOnTangent(fraction: number, distance: number): Point3d CurvePrimitive Construct a point extrapolated along tangent at fraction. fractionToPointAndUnitTangent(fraction: number, result?: Ray3d): Ray3d CurvePrimitive Returns a ray whose origin is the curve point and direction is the unit tangent. getFractionToDistanceScale(): number | undefined CurvePrimitive * If the curve primitive has distance-along-curve strictly proportional to curve fraction, return true moveSignedDistanceFromFractionGeneric(startFraction: number, signedDistance: number, allowExtension: boolean, result?: CurveLocationDetail): CurveLocationDetail Protected CurvePrimitive Generic algorithm to search for point at signed distance from a fractional startPoint. range(transform?: Transform, result?: Range3d): Range3d GeometryQuery return the range of the entire (tree) GeometryQuery tryTranslateInPlace(dx: number, dy: number = 0, dz: number = 0): boolean GeometryQuery try to move the geometry by dx,dy,dz installStrokeCountMap(curve: CurvePrimitive, curveMap: StrokeCountMap, parentMap?: StrokeCountMap): void Static CurvePrimitive final install step to save curveMap in curve. Properties Name Type Description curvePrimitiveType "lineString" = "lineString" String name for schema properties fractions Accessor ReadOnly GrowableFloat64Array | undefined Return array of fraction parameters. isExtensibleFractionSpace Accessor ReadOnly boolean A LineString3d extends along its first and final segments. isPhysicallyClosed Accessor ReadOnly boolean Returns true if first and last points are within metric tolerance. normalIndices Accessor ReadOnly GrowableFloat64Array | undefined Return the (optional) array of normal indices. packedDerivatives Accessor ReadOnly GrowableXYZArray | undefined Return the (optional) array of derivatives. packedPoints Accessor ReadOnly GrowableXYZArray Return (reference to) point data in packed GrowableXYZArray. packedSurfaceNormals Accessor ReadOnly GrowableXYZArray | undefined Return the (optional) array of surface normals. packedUVParams Accessor ReadOnly GrowableXYArray | undefined Return the (optional) array of uv params. paramIndices Accessor ReadOnly GrowableFloat64Array | undefined Return the (optional) array of param indices. pointIndices Accessor ReadOnly GrowableFloat64Array | undefined Return the (optional) array of point indices. points Accessor ReadOnly Point3d[] return the points array (cloned). Inherited properties Name Type Inherited from Description children Accessor ReadOnly GeometryQuery[] | undefined GeometryQuery return GeometryQuery children for recursive queries.* leaf classes do not need to implement. geometryCategory "curvePrimitive" = "curvePrimitive" CurvePrimitive String name for schema properties strokeData undefined | StrokeCountMap CurvePrimitive data attached during stroking for facets. Defined in core/geometry/src/curve/LineString3d.ts Line 82 Last Updated: 13 June, 2024