APPROXIMATION OF SURFACES BY CYLINDERS

We present a new method for approximation of a given surface by a cyli nder surface. It is a constructive geometric method, leading to a mono rail representation of the cylinder surface. By use of the Gaussian im age of the given surface, we determine a projection plane. In the orth ogonal projection of the surface onto this plane, a reference curve is determined by use of methods for thinning of binary images. Finally, the cylinder surface is constructed as follows: the directrix of the c ylinder surface is determined by a least squares method minimizing the distance to the points in the projection within a tolerance given by the reference curve, and the rulings are lines perpendicular to the pr ojection plane. An application of the method in ship design is given. (C) 1998 Elsevier Science Ltd. All rights reserved.