A system, method, and computer program for preserving design intent of a Non-Uniform Rational B-spline (NURBS) surface without representation of a parent surface, comprising representing an output surface having control points that is independent from a refinement of the surface; interpolating a base surface from the output surface; calculating a delta vector that is a difference between the output surface and the base surface; and transforming the delta vector based upon a local coordinate system of a normal vector and a tangent plane of the base surface and appropriate means and computer-readable instructions.