Approach for CAD model reconstruction basing on 3D points insertion and surface approximation

Reverse engineering (RE) consists in the reconstruction of a geometric model of a 3D object from a set of points, a mesh or a 3D triangulation. This model is a combination of geometric primitives (cylinders, planes, spheres, etc.) and complex surfaces (B-Spline, NURBS$\dots$) defined by parameters that can be estimated from the 3D data. RE is widely used in different fields such as mechanic, artistic, medical, Building Information Modeling, reality augmentation, etc. In this context, the reconstruction of 3D surface is an important task to obtain the Computer Aided Design (CAD) model in order to visualize 3D objects and approximate their shapes by mathematical formulations. Triangular surface models are now commonly used to model three-dimensional object. Many of these geometric models are obtained from scanning techniques or modeled through CAD software. This paper presents a new approach to rebuild a CAD model basing on the reconstruction of the B-Spline surfaces given a set of points extracted from a deformed mesh. To guarantee a good precision of the fitted surface, new 3D points are inserted to the input mesh using the Walton's method. Given the updated set of points, the B-Spline surface is approximated. To validate the proposed method, reconstruction errors of different complex 3D surfaces before and after the points insertion are calculated. A comparison with the existing methods prove the efficiency of the developed algorithm.