Function IGetBSurfParams() As System.Double

Dim instance As ISurface
Dim value As System.Double
 
value = instance.IGetBSurfParams()

System.double IGetBSurfParams()

System.double IGetBSurfParams(); 

Return Value

• in-process, unmanaged C++: Pointer to an array of doubles (see Remarks) 

For COM applications, the following values must be set up in a previous call to ISurface::IGetBSurfParamsSize3:

• vP0 [0] & vP0 [2] are the lower bounds of the U & V surface parameters, respectively.
• vP0 [1] & vP0 [3] are the upper bounds of the U & V surface parameters, respectively.

If you want to use the Bsurface in combination with its trim curves, you should use the IFace2::GetTrimCurves2 method to extract the trim curves and the Bsurface. The IFace2::GetTrimCurves method provides better alignment of the trim curves with the Bsurface because they are both generated at the same time.

Evaluation is as follows:

Number of returned double elements is (4 + NumUKnots + NumVKnots + NumControlPointDoubles), where NumUKnots = (NumColumnsControlPoints + Uorder) and NumVKnots = (NumRowsControlPoints + Vorder).

The returned data are arranged in the following order:

• Uorder, Vorder - These are two ints packed into a double

• Uorder - Order of surface in U direction.

• Vorder - Order of surface in V direction.

• NumColumnsControlPoints, NumRowsControlPoints - These are two ints packed into a double

• NumColumnsControlPoints - Number of columns for the control points.

• NumRowsControlPoints - Number of rows for the control points.

• Uperiodicity, Vperiodicity - These are two ints packed into a double. Because you may be generating a Bsurface with this function, the U,V periodicity values may be opposite from the original surface. See ISurface::Parameterization or ISurface::IParameterization.

• Uperiodicity - TRUE if surface is periodic in U direction.

• Uperiodicity - TRUE if surface is periodic in V direction.

• DimensionControlPoints, dummy - These are two ints packed into a double

• DimensionControlPoints - Dimension for control points.

• DimensionControlPoints = 3 for non-rational surfaces and control point coordinates are output as [x0,y0,z0,x1,y1,z1,.........].

• DimensionControlPoints = 4 for rational surfaces and control point coordinates and the weight are output as [x0,y0,z0,w0,x1,y1,z1,w1,........].

• dummy - a system used filler.

• UKnots - Knot vector in the u direction

There will be (NumColumnsControlPoints + Uorder) knot values. If the surface is periodic in the U direction, then data will be converted and returned in a non-periodic form with additional knots added to the surface ends.

• VKnots - Knot vector in the v direction.

There will be (NumRowsControlPoints + Vorder) knot values. If the surface is periodic in the V direction, then data will be converted and returned in a non-periodic form with additional knots added to the surface ends.

• ControlPoints - This is a list of control points output in (NumColumnsControlPoints*NumRowsControlPoints) vectors of dimension DimensionControlPoints. The vectors are output row by row. The U direction of surface is in the row direction. The V direction of surface is in the column direction.

• For non-rational surfaces, control point coordinates are output as [x0,y0,z0,x1,y1,z1,.........].

• For rational surfaces, control point coordinates and the weight are output as [x0,y0,z0,w0,x1,y1,z1,w1,........].