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CreateSplineByEqnParams Method (ISketchManager)

Creates a B-curve from B-spline data; that is, a set of B-spline vertices (control points) and a knot vector.

.NET Syntax

Visual Basic (Declaration) 
Function CreateSplineByEqnParams( _
   ByVal Parameters As System.Object _
) As SketchSegment
Visual Basic (Usage) 
Dim instance As ISketchManager
Dim Parameters As System.Object
Dim value As SketchSegment
value = instance.CreateSplineByEqnParams(Parameters)
SketchSegment CreateSplineByEqnParams( 
   System.object Parameters
SketchSegment^ CreateSplineByEqnParams( 
&   System.Object^ Parameters


Array containing an array of doubles to use in creating the spline (see Remarks)

Return Value

Sketch segment for the spline


The Properties array contains four longs (placed in the first four doubles in the array):

  • Dimension

  • Order

  • Number of Control Points

  • Periodicity ( true or false)

The Knots array contains doubles with (Number of Control Points + Order) elements.

The size of the ControlPoints array is based upon the curve dimension.

  • Dimension = 2 then each Control Point is an array of 2 doubles ( x, y )

  • Dimension = 3 then each Control Point is an array of 3 doubles ( x, y, z)

  • Dimension = 4 then each Control Point is an array of 4 doubles ( x, y, z, w ) where w = weight

The parameters are provided as three arrays.

Pass the control point coordinates to this routine in sketch space. The Z value is  interpreted as 0. In certain situations, you must transform your B-curve parameters to sketch space using ISketch::ModelToSketchTransform.

NOTE: The curve can be either periodic or non-periodic. If the generated spline is a closed spline, then it must be flagged as periodic. Additionally, splines generated in sketches must be G1 continuous. If the data passed to this method does not generate a G1 continuous spline, then it is rejected and a spline is not created. If your data is not G1 continuous, then you must split the spline into multiple G1 segments and call this method for each segment.

This method does not work with ISketchManager::AddToDB or ISketchManager::DisplayWhenAdded. It always adds the spline directly to the database (as if ISketchManager::AddToDB(True) is in effect), and you must redraw your document window to see the entities that you added (as if ISketchManager::DisplayWhenAdded(False) is in effect).

To create 3D splines, see IModelDoc2::InsertCurveFilePoint and related functions.


See Also


SolidWorks 2008 FCS, Revision Number 16.0

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