This .NET class wraps the AcGeCubicSplineCurve3d ObjectARX class. This class represents an interpolation cubic spline in 3D space.

Autodesk.AutoCAD.Geometry.Entity3d
    Autodesk.AutoCAD.Geometry.Curve3d
        Autodesk.AutoCAD.Geometry.SplineEntity3d
            Autodesk.AutoCAD.Geometry.CubicSplineCurve3d

Public sealed Class CubicSplineCurve3d
Inherits SplineEntity3d

public sealed class CubicSplineCurve3d : SplineEntity3d;