OBJ is a file format developed by Wavefront that is commonly used to store 3D model geometric definitions. It is mainly used as an exchange format between different 3D applications and has become one of de-facto standards for model interoperability. Many 3D model libraries provide an option to download their models in this neutral format.
With Teigha you can create Non-Uniform Rational Basis Spline (NURBS) curves using the Teigha Ge library and its classes OdGeNurbCurve2d and OdGeNurbCurve3d.
Let’s consider a 3D version of a curve (2D curves have all the same behavior). A NURBS curve is defined by its order, a set of weighted control points, and a knot vector. This data can be set to a curve using a constructor: