CAD-BASED SURFACE FITTING FROM RANGE DATA

In this paper, we present a methodology permitting the conversion of the range data into free-form surface models using patches that are common in current CAD packages, namely rectangular Beziers or NURBS. Our aim is to fit a set of tensor product surface patches globally G1 or G2, of arbitrary topological type, to structured or unorganized range data. In this method the range data is first segmented. Then each subdivision is independently modelled. The three key points of this approach are segmentation, parameterisation of each subdivision (patch) and approximation of the surface model of each patch, and the joining of different calculated patches. To overcome the limitations of classical parameterisation methods, we propose a new and efficient methodology derived from conformal mapping techniques. A surface joining method is also presented. The segmentation is not detailed in this paper.