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This paper presents a method to decompose three dimensional complex parts into readily available stock material to take advantage of advanced joining to build up a rigid assembly. The method generates many alternative assemblies by decomposing the solid geometry iteratively with cutting planes. Each assembly is then evaluated based on cost. The process continues until the developed search algorithm converges on a near optimal solution. Application of this method will reduce material waste, thus reducing per part processing time, energy consumption, and associated production costs. Example parts for a variety of metals show how the computational tool finds near optimal solutions for complex three dimensional solids.

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This paper presents a structure-altering feature-based editing scheme for triangle mesh models of primitives for engineering application. With the increasing usage of 3D scanning and 3D printing technologies in product design, triangle mesh has become a vital model format in engineering designs. Coupled with its flexible nature in shape manipulation, many design models are now constructed in a mesh form. However, methods to perform direct feature-based mesh model modifications are lacking. Editing features and their defining parameters is greatly underdeveloped for mesh models compared with their parametric model counterparts. Thus, the proposed scheme aims to enable structure-altering feature-based mesh editing through the imposition (mapping) of a feature information layer on top of the triangle mesh model. Feature-based editing is done on the feature information layer. Through information mapping, the mesh model adapts to changes in the feature information layer, resulting in a geometric representation that accurately reflects the feature information layer content. Large-scale model modifications with structure-altering edits are thus achievable for mesh models, allowing straightforward feature-based model editing without the loss of the flexible mesh representation. Numerous case studies have been done to illustrate the effectiveness of the presented feature-based editing scheme. ARTICLE HISTORY

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passed away on May 1, 2018, 11 days short of being 90 years old.He was an early pioneer in the application of splines to Computer-Aided Geometric Design (CAGD), which provides the mathematical basis for the use of computers to design, engineer and manufacture products and complex systems.My first encounter with Prof. Boehm's work was in early 1981. I was new to CAGD and particularly interested in developing rational B-spline technology for use in engineering applications. Upon discovering his 1980 paper: "Inserting new knots into B-spline curves," my first impression was: what a beautiful work. It was short, just three pages, elegantly simple and clear, but eminently useful. The applications were immediately clear: curve/surface division, modification by means of control point refinement, decomposition into Bezier and other polynomial forms, and rendering sets of curves compatible for the purpose of surface constructions such as lofting, just to name a few. This paper had a profound influence on my work.