NurbCurve3d(Int32, KnotCollection, Point3dCollection, DoubleCollection, Boolean) Constructor

Constructor for the NurbCurve3d class. Constructs a 3D curve according to the passed parameters.

Namespace: Teigha.Geometry
Assembly: TD_Mgd (in TD_Mgd.dll) Version: 24.2.0.0

Syntax

public NurbCurve3d(
        int degree,
        KnotCollection knots,
        Point3dCollection controlPoints,
        DoubleCollection weights,
        bool periodic
)

Public Sub New ( 
        degree As Integer,
        knots As KnotCollection,
        controlPoints As Point3dCollection,
        weights As DoubleCollection,
        periodic As Boolean
)

public:
NurbCurve3d(
        int degree, 
        KnotCollection^ knots, 
        Point3dCollection^ controlPoints, 
        DoubleCollection^ weights, 
        bool periodic
)

new : 
        degree : int * 
        knots : KnotCollection * 
        controlPoints : Point3dCollection * 
        weights : DoubleCollection * 
        periodic : bool -> NurbCurve3d

Parameters

degree Int32: [in] Curve degree.
knots KnotCollection: [in] Knot collection.
controlPoints Point3dCollection: [in] Collection of control points.
weights DoubleCollection: [in] Collection of weight values.
periodic Boolean: [in] Flag that specifies whether to make the curve periodic (a closed curve).

Remarks

High degree values make the curve more flexible. For example, degree of 1 is used to define a segment, and degree of 2 is used to define a NURBS circle, etc. A knot vector defines a sequence of parameter values that determine where and how the control points affect the curve. The knot vector is a sequence of parameter values and divides the parametric space into intervals, usually called knot spans. Values of the knot vector must be provided in ascending order, for example: (0, 0, 0, 1, 2, 3, 3, 3) can be valid while (0, 0, 2, 0, 3, 1, 3, 3) is not valid. The control points specify the placement of the curve and adjust its shape. The quantity of control points must be at least the degree + 1. The closer the weight value is to zero, the closer the curve is to a straight line near the corresponding control point. If the weight increases, the curve pulls toward the corresponding control point. If the weight decreases, the curve pushes from the corresponding control point. If isPeriodic is false, knots.length() must equal controlPoints.length() + degree + 1. If isPeriodic is true, knots.length() must equal controlPoints.length(), and the first and last controlPoints must be equal.

Reference

NurbCurve3d Class

NurbCurve3d Overload

Teigha.Geometry Namespace