Curve

Public Class

Represents a base class that is common to most RhinoCommon curve types.

A curve represents an entity that can be all visited by providing a single parameter, usually called t.

Inheritance Hierarchy

System.Object
Rhino.Runtime.CommonObject
Rhino.Geometry.GeometryBase
Rhino.Geometry.Curve

Assembly: RhinoCommon (in RhinoCommon.dll)

Syntax

[SerializableAttribute]
public class Curve : GeometryBase

The Curve type exposes the following members.

Constructors

Name

Description

Protected Method

Curve

Protected serialization constructor for internal use.

Properties

Name

Description

Public Property

Degree

Gets the maximum algebraic degree of any span or a good estimate if curve spans are not algebraic.

Public Property

Dimension

Gets the dimension of the object.

The dimension is typically three. For parameter space trimming curves the dimension is two. In rare cases the dimension can be one or greater than three.

Public Property

Disposed

Indicates if this object has been disposed or the document it originally belonged to has been disposed.

(Inherited from CommonObject.)

Public Property

Domain

Gets or sets the domain of the curve.

Public Property

HasBrepForm

Returns true if the Brep.TryConvertBrep function will be successful for this object

(Inherited from GeometryBase.)

Public Property

HasUserData

Gets true if this class has any custom information attached to it through UserData.

(Inherited from CommonObject.)

Public Property

IsClosed

Gets a value indicating whether or not this curve is a closed curve.

Public Property

IsDeformable

true if object can be accurately modified with “squishy” transformations like projections, shears, and non-uniform scaling.

(Inherited from GeometryBase.)

Public Property

IsDocumentControlled

If true this object may not be modified. Any properties or functions that attempt to modify this object when it is set to “IsReadOnly” will throw a NotSupportedException.

(Inherited from GeometryBase.)

Public Property

IsPeriodic

Gets a value indicating whether or not this curve is considered to be Periodic.

Public Property
IsSubDFriendly

Returns true if the curve is a cubic, non-rational, uniform NURBS curve that is either periodic or has natural end conditions. Otherwise, false is returned.

Public Property

IsValid

Tests an object to see if it is valid.

(Inherited from CommonObject.)

Public Property

ObjectType

Useful for switch statements that need to differentiate between basic object types like points, curves, surfaces, and so on.

(Inherited from GeometryBase.)

Public Property

PointAtEnd

Evaluates point at the end of the curve.

Public Property

PointAtStart

Evaluates point at the start of the curve.

Public Property

SpanCount

Gets the number of non-empty smooth (c-infinity) spans in the curve.

Public Property
TangentAtEnd

Evaluate unit tangent vector at the end of the curve.

Public Property
TangentAtStart

Evaluates the unit tangent vector at the start of the curve.

Public Property

UserData

List of custom information that is attached to this class.

(Inherited from CommonObject.)

Public Property

UserDictionary

Dictionary of custom information attached to this class. The dictionary is actually user data provided as an easy to use shareable set of information.

(Inherited from CommonObject.)

Public Property

UserStringCount

Gets the amount of user strings.

(Inherited from GeometryBase.)

Methods

Name

Description

Public Method

ChangeClosedCurveSeam

If this curve is closed, then modify it so that the start/end point is at curve parameter t.

Public Method

ChangeDimension

Changes the dimension of a curve.

Public Method

ClosedCurveOrientation.

Determines the orientation (counterclockwise or clockwise) of a closed, planar curve in the world XY plane. Only works with simple (no self intersections) closed, planar curves.

Public Method

ClosedCurveOrientation(Plane)

Determines the orientation (counterclockwise or clockwise) of a closed, planar curve in a given plane. Only works with simple (no self intersections) closed, planar curves.

Public Method

ClosedCurveOrientation(Transform)

Determines the orientation (counterclockwise or clockwise) of a closed, planar curve. Only works with simple (no self intersections) closed, planar curves.

Public Method

ClosedCurveOrientation(Vector3d)

Determines the orientation (counterclockwise or clockwise) of a closed, planar curve in a given plane. Only works with simple (no self intersections) closed, planar curves.

Public Method

ClosestPoint(Point3d, Double.)

Finds parameter of the point on a curve that is closest to testPoint. If the maximumDistance parameter is > 0, then only points whose distance to the given point is <= maximumDistance will be returned. Using a positive value of maximumDistance can substantially speed up the search.

Public Method

ClosestPoint(Point3d, Double., Double)

Finds the parameter of the point on a curve that is closest to testPoint. If the maximumDistance parameter is > 0, then only points whose distance to the given point is <= maximumDistance will be returned. Using a positive value of maximumDistance can substantially speed up the search.

Public Method

ClosestPoints(Curve, Point3d., Point3d.)

Gets closest points between this and another curves.

Public Method

ClosestPoints(IEnumerable.GeometryBase., Point3d., Point3d., Int32.)

Finds the object (and the closest point in that object) that is closest to this curve.

Breps, surfaces, curves and point clouds are examples of objects that can be passed to this function.

Public Method

ClosestPoints(IEnumerable.GeometryBase., Point3d., Point3d., Int32., Double)

Finds the object (and the closest point in that object) that is closest to this curve.

Breps, surfaces, curves and point clouds are examples of objects that can be passed to this function.

Public Method

CombineShortSegments

Looks for segments that are shorter than tolerance that can be combined. For NURBS of degree greater than 1, spans are combined by removing knots. Similarly for NURBS segments of polycurves. Otherwise, RemoveShortSegments() is called. Does not change the domain, but it will change the relative parameterization.

Public Method

ComponentIndex

If this piece of geometry is a component in something larger, like a BrepEdge in a Brep, then this function returns the component index.

(Inherited from GeometryBase.)

Protected Method

ConstructConstObject

Assigns a parent object and a sub-object index to this.

(Inherited from CommonObject.)

Public Method

Contains(Point3d)

Obsolete.

Computes the relationship between a point and a closed curve region. This curve must be closed or the return value will be Unset. Both curve and point are projected to the World XY plane.

Public Method

Contains(Point3d, Plane)

Obsolete.

Computes the relationship between a point and a closed curve region. This curve must be closed or the return value will be Unset.

Public Method

Contains(Point3d, Plane, Double)

Computes the relationship between a point and a closed curve region. This curve must be closed or the return value will be Unset.

Public Method

ControlPolygon

Gets the curve’s control polygon.

Public Method
Static Member

CreateArcBlend

Creates a polycurve consisting of two tangent arc segments that connect two points and two directions.

Public Method
Static Member

CreateArcCornerRectangle

Creates an arc-cornered (rounded) rectangular curve.

Public Method
Static Member
CreateArcLineArcBlend

Creates an arc-line-arc blend curve between two curves. The output is generally a PolyCurve with three segments: arc, line, arc. In some cases, one or more of those segments will be absent because they would have 0 length. If there is only a single segment, the result will either be an ArcCurve or a LineCurve.

Public Method
Static Member

CreateBlendCurve(Curve, Curve, BlendContinuity)

Create a Blend curve between two existing curves.

Public Method
Static Member

CreateBlendCurve(Curve, Curve, BlendContinuity, Double, Double)

Create a Blend curve between two existing curves.

Public Method
Static Member

CreateBlendCurve(Curve, Double, Boolean, BlendContinuity, Curve, Double, Boolean, BlendContinuity)

Makes a curve blend between 2 curves at the parameters specified with the directions and continuities specified

Public Method
Static Member

CreateBooleanDifference(Curve, Curve)

Obsolete.

Calculates the boolean difference between two closed, planar curves. Note, curves must be co-planar.

Public Method
Static Member

CreateBooleanDifference(Curve, IEnumerable.Curve.)

Obsolete.

Calculates the boolean difference between a closed planar curve, and a list of closed planar curves. Note, curves must be co-planar.

Public Method
Static Member

CreateBooleanDifference(Curve, Curve, Double)

Calculates the boolean difference between two closed, planar curves. Note, curves must be co-planar.

Public Method
Static Member

CreateBooleanDifference(Curve, IEnumerable.Curve., Double)

Calculates the boolean difference between a closed planar curve, and a list of closed planar curves. Note, curves must be co-planar.

Public Method
Static Member

CreateBooleanIntersection(Curve, Curve)

Obsolete.

Calculates the boolean intersection of two closed, planar curves. Note, curves must be co-planar.

Public Method
Static Member

CreateBooleanIntersection(Curve, Curve, Double)

Calculates the boolean intersection of two closed, planar curves. Note, curves must be co-planar.

Public Method
Static Member

CreateBooleanRegions(IEnumerable.Curve., Plane, Boolean, Double)

Calculates curve Boolean regions, which trims and splits curves based on their overlapping regions.

Public Method
Static Member

CreateBooleanRegions(IEnumerable.Curve., Plane, IEnumerable.Point3d., Boolean, Double)

Curve Boolean method, which trims and splits curves based on their overlapping regions.

Public Method
Static Member

CreateBooleanUnion(IEnumerable.Curve.)

Obsolete.

Calculates the boolean union of two or more closed, planar curves. Note, curves must be co-planar.

Public Method
Static Member

CreateBooleanUnion(IEnumerable.Curve., Double)

Calculates the boolean union of two or more closed, planar curves. Note, curves must be co-planar.

Public Method
Static Member

CreateConicCornerRectangle

Creates a conic-corned (rounded) rectangular curve.

Public Method
Static Member

CreateControlPointCurve(IEnumerable.Point3d.)

Constructs a control-point of degree=3 (or less).

Public Method
Static Member

CreateControlPointCurve(IEnumerable.Point3d., Int32)

Constructs a curve from a set of control-point locations.

Public Method
Static Member

CreateCurve2View

Creates a third curve from two curves that are planar in different construction planes. The new curve looks the same as each of the original curves when viewed in each plane.

Public Method
Static Member

CreateFillet

Computes the fillet arc for a curve filleting operation.

Public Method
Static Member

CreateFilletCornersCurve

Rounds the corners of a kinked curve with arcs of a single, specified radius.

Public Method
Static Member
Code Example

CreateFilletCurves

Creates a tangent arc between two curves and trims or extends the curves to the arc.

Public Method
Static Member

CreateInterpolatedCurve(IEnumerable.Point3d., Int32)

Interpolates a sequence of points. Used by InterpCurve Command This routine works best when degree=3.

Public Method
Static Member

CreateInterpolatedCurve(IEnumerable.Point3d., Int32, CurveKnotStyle)

Interpolates a sequence of points. Used by InterpCurve Command This routine works best when degree=3.

Public Method
Static Member

CreateInterpolatedCurve(IEnumerable.Point3d., Int32, CurveKnotStyle, Vector3d, Vector3d)

Interpolates a sequence of points. Used by InterpCurve Command This routine works best when degree=3.

Public Method
Static Member

CreateMatchCurve

Changes a curve end to meet a specified curve with a specified continuity.

Public Method
Static Member

CreateMeanCurve(Curve, Curve)

Constructs a mean, or average, curve from two curves.

Public Method
Static Member

CreateMeanCurve(Curve, Curve, Double)

Constructs a mean, or average, curve from two curves.

Public Method
Static Member

CreatePeriodicCurve(Curve)

Removes kinks from a curve. Periodic curves deform smoothly without kinks.

Public Method
Static Member

CreatePeriodicCurve(Curve, Boolean)

Removes kinks from a curve. Periodic curves deform smoothly without kinks.

Public Method
Static Member

CreateSoftEditCurve

Creates a soft edited curve from an existing curve using a smooth field of influence.

Public Method
Static Member

CreateTextOutlines

Creates outline curves created from a text string. The functionality is similar to what you find in Rhino’s TextObject command or TextEntity.Explode() in RhinoCommon.

Public Method
Static Member

CreateTweenCurves(Curve, Curve, Int32)

Obsolete.

Creates curves between two open or closed input curves. Uses the control points of the curves for finding tween curves. That means the first control point of first curve is matched to first control point of the second curve and so on. There is no matching of curves direction. Caller must match input curves direction before calling the function.

Public Method
Static Member

CreateTweenCurves(Curve, Curve, Int32, Double)

Public Method
Static Member

CreateTweenCurvesWithMatching(Curve, Curve, Int32)

Obsolete.

Creates curves between two open or closed input curves. Make the structure of input curves compatible if needed. Refits the input curves to have the same structure. The resulting curves are usually more complex than input unless input curves are compatible and no refit is needed. There is no matching of curves direction. Caller must match input curves direction before calling the function.

Public Method
Static Member

CreateTweenCurvesWithMatching(Curve, Curve, Int32, Double)

Public Method
Static Member

CreateTweenCurvesWithSampling(Curve, Curve, Int32, Int32)

Obsolete.

Creates curves between two open or closed input curves. Use sample points method to make curves compatible. This is how the algorithm works: Divides the two curves into an equal number of points, finds the midpoint between the corresponding points on the curves and interpolates the tween curve through those points. There is no matching of curves direction. Caller must match input curves direction before calling the function.

Public Method
Static Member

CreateTweenCurvesWithSampling(Curve, Curve, Int32, Int32, Double)

Public Method
Code Example
CurvatureAt

Evaluate the curvature vector at a curve parameter.

Public Method

DataCRC

Returns a CRC calculated from the information that defines the object. This CRC can be used as a quick way to see if two objects are not identical.

(Inherited from GeometryBase.)

Public Method

DeleteAllUserStrings

(Inherited from GeometryBase.)

Public Method

DeleteUserString

(Inherited from GeometryBase.)

Public Method

DerivativeAt(Double, Int32)

Evaluate the derivatives at the specified curve parameter.

Public Method

DerivativeAt(Double, Int32, CurveEvaluationSide)

Evaluate the derivatives at the specified curve parameter.

Public Method

Dispose.

Actively reclaims unmanaged resources that this instance uses.

(Inherited from CommonObject.)

Protected Method

Dispose(Boolean)

For derived class implementers.

This method is called with argument true when class user calls Dispose(), while with argument false when the Garbage Collector invokes the finalizer, or Finalize() method.

You must reclaim all used unmanaged resources in both cases, and can use this chance to call Dispose on disposable fields if the argument is true.

Also, you must call the base virtual method within your overriding method.

(Overrides

GeometryBase.Dispose(Boolean)

Public Method

DivideAsContour

Divides this curve at fixed steps along a defined contour line.

Public Method

DivideByCount(Int32, Boolean)

Divide the curve into a number of equal-length segments.

Public Method

DivideByCount(Int32, Boolean, .Point3d..)

Divide the curve into a number of equal-length segments.

Public Method
Code Example

DivideByLength(Double, Boolean)

Divide the curve into specific length segments.

Public Method
Code Example

DivideByLength(Double, Boolean, .Point3d..)

Divide the curve into specific length segments.

Public Method
Code Example

DivideByLength(Double, Boolean, Boolean)

Divide the curve into specific length segments.

Public Method
Code Example

DivideByLength(Double, Boolean, Boolean, .Point3d..)

Divide the curve into specific length segments.

Public Method

DivideEquidistant

Calculates 3d points on a curve where the linear distance between the points is equal.

Public Method
Static Member

DoDirectionsMatch

Determines whether two curves travel more or less in the same direction.

Public Method

Duplicate

Constructs an exact duplicate of this Curve.

(Overrides

GeometryBase.Duplicate.

Public Method
Code Example

DuplicateCurve

Constructs an exact duplicate of this curve.

Public Method
DuplicateSegments

Duplicates curve segments. Explodes polylines, polycurves and G1 discontinuous NURBS curves. Single segment curves, such as lines, arcs, unkinked NURBS curves, are duplicated.

Public Method

DuplicateShallow

Constructs a light copy of this object. By “light”, it is meant that the same underlying data is used until something is done to attempt to change it. For example, you could have a shallow copy of a very heavy mesh object and the same underlying data will be used when doing things like inspecting the number of faces on the mesh. If you modify the location of one of the mesh vertices, the shallow copy will create a full duplicate of the underlying mesh data and the shallow copy will become a deep copy.

(Inherited from GeometryBase.)

Public Method

EnsurePrivateCopy

If you want to keep a copy of this class around by holding onto it in a variable after a command completes, call EnsurePrivateCopy to make sure that this class is not tied to the document. You can call this function as many times as you want.

(Inherited from CommonObject.)

Public Method

Equals

Determines whether the specified object is equal to the current object.

(Inherited from Object.)

Public Method

Extend(Interval)

Where possible, analytically extends curve to include the given domain. This will not work on closed curves. The original curve will be identical to the restriction of the resulting curve to the original curve domain.

Public Method

Extend(Double, Double)

Public Method

Extend(CurveEnd, CurveExtensionStyle, Point3d)

Extends a curve to a point.

Public Method
Code Example

Extend(CurveEnd, CurveExtensionStyle, IEnumerable.GeometryBase.)

Extends a curve until it intersects a collection of objects.

Public Method

Extend(CurveEnd, Double, CurveExtensionStyle)

Extends a curve by a specific length.

Public Method

ExtendByArc

Extends a curve by an Arc until it intersects a collection of objects.

Public Method

ExtendByLine

Extends a curve by a line until it intersects a collection of objects.

Public Method

ExtendOnSurface(CurveEnd, BrepFace)

Extends a curve on a surface.

Public Method

ExtendOnSurface(CurveEnd, Surface)

Extends a curve on a surface.

Public Method

ExtremeParameters

Returns the parameter values of all local extrema. Parameter values are in increasing order so consecutive extrema define an interval on which each component of the curve is monotone. Note, non-periodic curves always return the end points.

Public Method

Fair

Fairs a curve object. Fair works best on degree 3 (cubic) curves. Attempts to remove large curvature variations while limiting the geometry changes to be no more than the specified tolerance.

Public Method

FilletSurfaceToCurve

Creates a constant-radius fillet surface between a surface and the curve.

Public Method
FilletSurfaceToRail

Creates a surface between two surfaces, with a fixed rail curve on the first surface.

Protected Method

Finalize

Passively reclaims unmanaged resources when the class user did not explicitly call Dispose().

(Inherited from CommonObject.)

Public Method
FindLocalInflection

Local minimization for point on a curve with tangent perpendicular to N.

Public Method

Fit

Fits a new curve through an existing curve.

Public Method

FrameAt

Returns a 3d frame at a parameter.

Public Method
Code Example

GetBoundingBox(Boolean)

Bounding box solver. Gets the world axis aligned bounding box for the geometry.

(Inherited from GeometryBase.)

Public Method
Code Example

GetBoundingBox(Plane)

Aligned Bounding box solver. Gets the plane aligned bounding box.

(Inherited from GeometryBase.)

Public Method

GetBoundingBox(Transform)

Aligned Bounding box solver. Gets the world axis aligned bounding box for the transformed geometry.

(Inherited from GeometryBase.)

Public Method

GetBoundingBox(Plane, Box.)

Aligned Bounding box solver. Gets the plane aligned bounding box.

(Inherited from GeometryBase.)

Public Method

GetConicSectionType.

Returns the type of conic section based on the curve’s shape.

Public Method

GetConicSectionType(Point3d., Point3d., Point3d.)

Returns the type of conic section based on the curve’s shape.

Public Method
GetCurveParameterFromNurbsFormParameter

Convert a NURBS curve parameter to a curve parameter.

Public Method
Static Member
Code Example

GetDistancesBetweenCurves

Calculates the minimum and maximum distances between two curves. This function is useful for computing curve deviation. If you are not computing curve deviation, use .

Public Method
Static Member
GetFilletPoints

Finds points at which to cut a pair of curves so that a fillet of given radius can be inserted.

Public Method

GetHashCode

Serves as the default hash function.

(Inherited from Object.)

Public Method
Code Example

GetLength.

Gets the length of the curve with a fractional tolerance of 1.0e-8.

Public Method

GetLength(Double)

Get the length of the curve.

Public Method

GetLength(Interval)

Get the length of a sub-section of the curve with a fractional tolerance of 1e-8.

Public Method

GetLength(Double, Interval)

Get the length of a sub-section of the curve.

Public Method

GetLocalPerpPoint(Point3d, Double, Double.)

Search for a location on the curve, near seedParmameter, that is perpendicular to a test point.

Public Method

GetLocalPerpPoint(Point3d, Double, Interval, Double.)

Search for a location on the curve, near seedParmameter, that is perpendicular to a test point.

Public Method

GetLocalTangentPoint(Point3d, Double, Double.)

Search for a location on the curve, near seedParmameter, that is tangent to a test point.

Public Method

GetLocalTangentPoint(Point3d, Double, Interval, Double.)

Search for a location on the curve, near seedParmameter, that is tangent to a test point.

Public Method

GetNextDiscontinuity(Continuity, Double, Double, Double.)

Searches for a derivative, tangent, or curvature discontinuity.

Public Method

GetNextDiscontinuity(Continuity, Double, Double, Double, Double, Double.)

Searches for a derivative, tangent, or curvature discontinuity.

Public Method
GetNurbsFormParameterFromCurveParameter

Convert a curve parameter to a NURBS curve parameter.

Public Method

GetObjectData

Populates a System.Runtime.Serialization.SerializationInfo with the data needed to serialize the target object.

(Inherited from CommonObject.)

Public Method

GetPerpendicularFrames

Gets a collection of perpendicular frames along the curve. Perpendicular frames are also known as ‘Zero-twisting frames’ and they minimize rotation from one frame to the next.

Public Method
GetSubCurves

Gets subcurves from a curve. The results will be similar to what is produced by Rhino’s Explode command.

Public Method

GetType

Gets the Type of the current instance.

(Inherited from Object.)

Public Method

GetUserString

Gets user string from this geometry.

(Inherited from GeometryBase.)

Public Method

GetUserStrings

Gets a copy of all (user key string, user value string) pairs attached to this geometry.

(Inherited from GeometryBase.)

Public Method

HasNurbsForm

Does a NURBS curve representation of this curve exist?

Public Method

InflectionPoints.

Returns a curve’s inflection points. An inflection point is a location on a curve at which the sign of the curvature (i.e., the concavity) changes. The curvature at these locations is always 0.

Public Method

InflectionPoints(.Double..)

Returns a curve’s inflection points. An inflection point is a location on a curve at which the sign of the curvature (i.e., the concavity) changes. The curvature at these locations is always 0.

Public Method

IsArc.

Test a curve to see if it can be represented by an arc or circle within RhinoMath.ZeroTolerance.

Public Method

IsArc(Double)

Test a curve to see if it can be represented by an arc or circle within the given tolerance.

Public Method

IsCircle.

Test a curve to see if it can be represented by a circle within RhinoMath.ZeroTolerance.

Public Method

IsCircle(Double)

Test a curve to see if it can be represented by a circle within the given tolerance.

Public Method

IsClosable(Double)

Decide if it makes sense to close off this curve by moving the endpoint to the start based on start-end gap size and length of curve as approximated by chord defined by 6 points.

Public Method

IsClosable(Double, Double, Double)

Decide if it makes sense to close off this curve by moving the endpoint to the start based on start-end gap size and length of curve as approximated by chord defined by 6 points.

Public Method

IsContinuous

Test continuity at a curve parameter value.

Public Method

IsEllipse.

Test a curve to see if it can be represented by an ellipse within RhinoMath.ZeroTolerance.

Public Method

IsEllipse(Double)

Test a curve to see if it can be represented by an ellipse within a given tolerance.

Public Method

IsInPlane(Plane)

Test a curve to see if it lies in a specific plane.

Public Method

IsInPlane(Plane, Double)

Test a curve to see if it lies in a specific plane.

Public Method
Code Example

IsLinear.

Test a curve to see if it is linear to within RhinoMath.ZeroTolerance units (1e-12).

Public Method

IsLinear(Double)

Test a curve to see if it is linear to within the custom tolerance.

Public Method
Code Example

IsPlanar.

Test a curve for planarity.

Public Method

IsPlanar(Double)

Test a curve for planarity.

Public Method
Code Example

IsPolyline

Several types of Curve can have the form of a polyline including a degree 1 NurbsCurve, a PolylineCurve, and a PolyCurve all of whose segments are some form of polyline. IsPolyline tests a curve to see if it can be represented as a polyline.

Public Method
Code Example
IsShort(Double)

Used to quickly find short curves.

Public Method
IsShort(Double, Interval)

Used to quickly find short curves.

Public Method

IsValidWithLog

Determines if an object is valid. Also provides a report on errors if this object happens not to be valid.

(Inherited from CommonObject.)

Public Method
Static Member

JoinCurves(IEnumerable.Curve.)