CHARACTERISATION OF RATIONAL AND NURBS DEVELOPABLE SURFACES IN COMPUTER AIDED DESIGN

In this paper we provide a characterisation of rational developable surfaces in terms of the blossoms of the bounding curves and three rational functions Lambda, M, nu. Properties of developable surfaces are revised in this framework. In particular, a closed algebraic formula for the edge of regression of the surface is obtained in terms of the functions Lambda, M, nu, which are closely related to the ones that appear in the standard decomposition of the derivative of the parametrisation of one of the bounding curves in terms of the director vector of the rulings and its derivative. It is also shown that all rational developable surfaces can be described as the set of developable surfaces which can be constructed with a constant Lambda, M, nu. The results are readily extended to rational spline developable surfaces.

Automated summary

This paper provides a characterization of rational developable surfaces using the blossoms of bounding curves and three rational functions Lambda, M, nu. It presents a closed algebraic formula for the regression edge of the surface in terms of these functions. All rational developable surfaces can be described as the set of surfaces constructed with constant Lambda, M, nu. The results are also applicable to rational spline developable surfaces.