AcGeNurbCurve3d::AcGeNurbCurve3d Constructor (int, AcGeKnotVector&, AcGePoint3dArray&, AcGeDoubleArray&, Adesk::Boolean)

AcGeNurbCurve3d(
    int degree, 
    const AcGeKnotVector& knots, 
    const AcGePoint3dArray& cntrlPnts, 
    const AcGeDoubleArray& weights, 
    Adesk::Boolean isPeriodic = Adesk::kFalse
);

Parameters

Parameters	Description
int degree	Input degree of spline
const AcGeKnotVector& knots	Input array of knot values, partitioning spline's domain into rational pieces
const AcGePoint3dArray& cntrlPnts	Input array of 3D control points
const AcGeDoubleArray& weights	Input array of weight values
Adesk::Boolean isPeriodic = Adesk::kFalse	Input flag indicating if spline is a periodic

Description

Constructs a 3D rational spline by a knot vector, control points, and weights. If the spline is rational, control points and weights must have same length.

If isPeriodic = Adesk::kFalse then the length of knot vector must be greater than the length of the control array by degree+1.

If isPeriodic = Adesk::kTrue then one of the following must be true:

The length of the knot vector must be greater than length of the control array by 1. The first and the last control points must NOT be identical.
The knot vector and control array must have same length, and the first and the last control points must be identical.

Remarks

When creating periodic spline, we accept two data formats:

The length of knot vector must be greater than length of the control array by 1. The first and the last control points must NOT be identical.
The knot vector and control array must have same length, and the first and the last control points must be identical.

We prefer the first format and we will return the same format when calling getDefinitionData(). We return the same format even if you pass in data in the second format.

The knot vector should contains distinct knot values. For example, if we want to create a periodic spline with four control points, the knot vector could be (0, 1, 2, 3, 4).

Links

AcGeNurbCurve3d