DECOMPOSITION OF TRIMMED SURFACES VIA GENERALIZED SUBDIVISION

Since most complex objects are generated by some sort of trimming process in geometric modeling system, the representation and processing of trimmed surfaces are very important in CAD.This paper investigates representations of trimmed Bezier surfaces by using generalized subdivision of rectangular Bezier surfaces. Applying constrained optimization methods and idea of scan line of computer graphics respectively,methods for approximating trimming curves by Bezier functions and algorithms for decomposing parameter domain of trimmed surfaces are developed. A trimmed Bezier is represented as a union of some integral Bezier surfaces by decomposing its domain.