Geometric and Feature modelling

Efficiency of boundary evaluation for a cellular model

Abstract

Feature modeling systems usually employ a boundary representation (b-rep) to store the shape information on a product. It has, however, been shown that a b-rep has a number of shortcomings, and that a cellular representation can be a valuable alternative. A cellular model stores additional shape information on features, including the feature faces that are not on the boundary of the product. Such information can be profitably used for several purposes.
A major operation in every feature modeling system is boundary evaluation, which computes the geometric model of a product, i.e. either the b-rep or the cellular model, from the features that have been specified by the user. Since boundary evaluation has to be executed each time a feature is added, removed or modified, its efficiency is of paramount importance.
In this paper, boundary evaluation for a cellular model is described in some detail. Its efficiency is compared to the efficiency of boundary evaluation for a b-rep, on the basis of both complexity analysis and performance measurements for the two types of evaluation. It turns out that boundary evaluation for a cellular model is, in fact, more efficient than for a b-rep, which makes cellular models even more attractive as an alternative to b-reps.

Reprinted from Computer-Aided Design, Vol. 37, Rafael Bidarra, Joaquim Madeira, Willem J Neels and Willem F Bronsvoort, Efficiency of boundary evaluation for a cellular model, pp. 1266-1284, © 2005, with permission from Elsevier Science.
Single copies of this article can be downloaded and printed for the reader's personal research and study only


download full paper


Bidarra R, Madeira J, Neels WJ and Bronsvoort WF (2005), Efficiency of boundary evaluation for a cellular model. Computer-Aided Design, Vol. 37, no. 12, pp. 1266-1284.