Free-Form Solid Modeling with Trimmed Surface Patches

Solid modelers store a more complete representation than wireframe or surtace modelers. This completeness permits the automation of such tasks as interference analysis, mass property calculation, and finite element mesh generation. But the denser information content and complex algorithms needed to perform these tasks complicate the support of free-form geometry, especially Boolean operations. Consequently, the high degree of geometric coverage traditionally found in surface modeling systems has not, for the most part, been equaled in modern solid modelers. This article explores some of the difficulties encountered in Boolean combinations of free-from solids and presents a geometric representation designed to circumvent them.