A Method of Representing the Solid Design Process

Wish modeling systems were more user friendly? This one quickly regenerates a solid design from previous developmental stages to ease the usual trial-and-error procedurtes     

Boolean operations for solids with free-form surfaces through polyhedral approximation

This paper describes a new implementation method for Boolean operations between solids with free-form surfaces. Boolean operations consist of two processes-topological modification and geometric modification-which are performed separately in our method. This separation makes the Boolean operation process simple and robust. Surfaces contained in the final solid are interpolated by the repatching facility using Gregory patches.     

An Extended Rounding Operation for Modeling Solids with Free-Form Surfaces

An extended rounding operation can be an excellent tool for modeling solids with free-form surfaces. Using the rounding operation, the edges and vertices of a solid can be locally rounded, and those parts of the solid are changed to free-form surfaces. As a user, you put in information about edges that should be rounded and the radii of curves generated by the operation. This facility has been implemented in our solid modeling system, Desiqnbase.     

UNDO and REDO Operations for Solid Modeling

This article describes a method of representing a solid design procss using a tree structure. This representation supposrts UNDO and REDO operations for regenerating any solid in a previous stage of the design. The implementations of invertible set operations is also given in detail.     

An approach of designing and controlling free-form surfaces by using NURBS boundary Gregory patches

Designers require a means of designing complex free-form surfaces easily and intuitively. One general approach to designing such surfaces is to first define a curve mesh consisting of characteristic lines, such as cross sections and boundary curves, then to interpolate the curve mesh using free-form surfaces. NURBS surfaces are widely used but make the interpolation of an irregular curve mesh difficult. This has been a major limiting constraint on designers. In this paper, we propose a new surface representation that enables the smooth interpolation of an irregular curve mesh with NURBS curves and surfaces.