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Create Method

Construct NurbsSurfaceData based on NURBS surface data, where the weights are supplied. The NURBS surface will be (piecewise) polynomial if all the weights are equal, rational if not. Note: A rational polynomial is a quotient of two polynomials; this includes a polynomial, which can be thought of as a quotient with denominator equal to 1.

Namespace: Autodesk.Revit.DB
Assembly: RevitAPI (in RevitAPI.dll) Version: 17.0.0.0 (17.0.484.0)
Since: 2016

Syntax

C# 
public static NurbsSurfaceData Create(
	int degreeU,
	int degreeV,
	IList<double> knotsU,
	IList<double> knotsV,
	IList<XYZ> controlPoints,
	IList<double> weights,
	bool bReverseOrientation
)
Visual Basic 
Public Shared Function Create ( _
	degreeU As Integer, _
	degreeV As Integer, _
	knotsU As IList(Of Double), _
	knotsV As IList(Of Double), _
	controlPoints As IList(Of XYZ), _
	weights As IList(Of Double), _
	bReverseOrientation As Boolean _
) As NurbsSurfaceData
Visual C++ 
public:
static NurbsSurfaceData^ Create(
	int degreeU, 
	int degreeV, 
	IList<double>^ knotsU, 
	IList<double>^ knotsV, 
	IList<XYZ^>^ controlPoints, 
	IList<double>^ weights, 
	bool bReverseOrientation
)

Parameters

degreeU
Type: System Int32
The degree of the spline in the u-direction; must be positive.
degreeV
Type: System Int32
The degree of the spline in the v-direction; must be positive.
knotsU
Type: System.Collections.Generic IList Double
Knot values in the u-direction. The number of knots in the u-direction must be at least 2 * (degreeU + 1).
knotsV
Type: System.Collections.Generic IList Double
Knot values in the v-direction. The number of knots in the v-direction must be at least 2 * (degreeV + 1).
controlPoints
Type: System.Collections.Generic IList XYZ
One dimensional array of points representing the two dimensional net of control points of the NURBS surface in u and v directions.

The total number of control points must equal numControlPtsU times numControlPtsV, where numControlPtsU and numControlPtsV are the numbers of control points in u and v directions, and they must satisfy the following conditions:

  • numControlPtsU = number of knots in u - degreeU - 1.
  • numControlPtsV = number of knots in v - degreeV - 1.
The convention for 2d (idxU, idxV) to 1d (idx) conversion of array indexes: idxV first. That is, idxU is outer loop and idxV is inner loop. In other words, idx = idxU * numControlPtsV + idxV.

weights
Type: System.Collections.Generic IList Double
Array of weights assigned to the control points. The number of weights must equal the number of control points. All weights should be greater than zero.
bReverseOrientation
Type: System Boolean
If true, the surface's orientation is opposite to the canonical parametric orientation, otherwise it is the same. The canonical parametric orientation is a counter-clockwise sense of rotation in the uv-parameter plane. Extrinsically, the oriented normal vector for the canonical parametric orientation points in the direction of the cross product dS/du x dS/dv, which S(u, v) is the parameterized surface.

Exceptions

Exception Condition
Autodesk.Revit.Exceptions ArgumentException The U-degree value must be at least 1. -or- The V-degree value must be at least 1. -or- The number of knots in the U direction must be at least 2 times the U-degree plus 1. -or- The number of knots in the V direction must be at least 2 times the V-degree plus 1. -or- The number of control points must equal (number of U-knots - U-degree - 1) * (number of V-knots - V-degree - 1). -or- The number of weights must be the same as the number of control points and all weights must be positive or all zero.
Autodesk.Revit.Exceptions ArgumentNullException A non-optional argument was NULL

See Also