General 2 rail sweep. If you are not producing the sweep results that you are after, then use the SweepTwoRail class with options to generate the swept geometry

Namespace: Rhino.Geometry
Assembly: RhinoCommon (in RhinoCommon.dll) Version: Rhino 6.0

C#

public static Brep[] CreateFromSweep(
	Curve rail1,
	Curve rail2,
	Curve shape,
	bool closed,
	double tolerance
)

VB

Public Shared Function CreateFromSweep ( 
	rail1 As Curve,
	rail2 As Curve,
	shape As Curve,
	closed As Boolean,
	tolerance As Double
) As Brep()

rail1

Type: Rhino.Geometry.Curve
Rail to sweep shapes along

rail2

Type: Rhino.Geometry.Curve
Rail to sweep shapes along

shape

Type: Rhino.Geometry.Curve
Shape curve

closed

Type: System.Boolean
Only matters if shape is closed

tolerance

Type: System.Double
Tolerance for fitting surface and rails

Type: Brep[]
Array of Brep sweep results

Supported in: 6.0.16224.21491, 5D58w

Brep Class
CreateFromSweep Overload
Rhino.Geometry Namespace