1 Aims and Features of This Book The contents of t. his book were originally planned t. o be included in a book en titled Geometric lIIodeling and CAD/CAM to be written by M. Hosaka and F. Kimura, but since the draft. of my part of the book was finished much earlier than Kimura's, we decided to publish this part separately at first. In it, geometrically oriented basic methods and tools used for analysis and synthesis of curves and surfaces used in CAD/CAM, various expressions and manipulations of free-form surface patches and their connection, interference as well as their qualit. y eval uation are treated. They are important elements and procedures of geometric models. And construction and utilization of geometric models which include free-form surfaces are explained in the application examples, in which the meth ods and the techniques described in this book were used. In the succeeding book which Kimura is to write, advanced topics such as data structures of geometric models, non-manifold models, geometric inference as well as tolerance problems and product models, process planning and so on are to be included. Conse quently, the title of this book is changed to Modeling of Curves and Surfaces in CAD/CAM. Features of this book are the following. Though there are excellent text books in the same field such as G. Farin's Curves and Surfaces for CAD /CAM[l] and C. M.

Curved object manufacturing has become an important subject in modern industry as more varieties of industrial products are being designed with sculptured surfaces. Known as CAMM (computer-aided modeling & machining), the subject is rapidly becoming one of the most critical issues in CAD/CAM. Up till now, there has been a gap between the theory in CAGD (computer-aided geometric design) and the practices in CAMM. The aim of this volume is to fill the gap by presenting a comprehensive coverage of practical solutions for engineers, while at the same time providing problems for researchers. The main focus of the work is on the approach to and strategy for solving engineering problems. A sound understanding of the structure or domain of the problem as well as available techniques or tools is provided in each case, with the main emphasis being on descriptive shape models. The broad mathematical principles of CAGD are covered, in addition to some details of practical implementation. The book is self-contained in that an undergraduate level of algebraic calculus is sufficient to follow the discussions.

Shape interrogation is the process of extraction of information from a geometric model. It is a fundamental component of Computer Aided Design and Manufacturing (CAD/CAM) systems. The authors focus on shape interrogation of geometric models bounded by free-form surfaces. Free-form surfaces, also called sculptured surfaces, are widely used in the bodies of ships, automobiles and aircraft, which have both functionality and attractive shape requirements. Many electronic devices as well as consumer products are designed with aesthetic shapes, which involve free-form surfaces. This book provides the mathematical fundamentals as well as algorithms for various shape interrogation methods including nonlinear polynomial solvers, intersection problems, differential geometry of intersection curves, distance functions, curve and surface interrogation, umbilics and lines of curvature, geodesics, and offset curves and surfaces. This book will be of interest both to graduate students and professionals.

On November 9-11, 1998,85 participants, representing 17 countries, gathered in Aubum Hills, Michigan, at the Chrysler Tech Center, to attend a workshop "SSM'98" (or Sculptured Surface Machining '98) organized by IFIP Working Group 5.3. This was the first major workshop on sculptured surface machining since the CAM-I sponsored conference "Machining Impossible Surfaces" held in 1981. The purpose of the SSM'98 workshop, entitled "Machining Impossible Shapes", was to promote a cross-fertilization of ideas among three communities: industrial users, CAM software developers and academic researchers. There were 17 participants who were "industrial users", 15 represented CAM software developers, 4 were from the machine tool industry, with the remainder being academic researchers. The format of the meeting included 40 presentations in 9 sessions, 4 keynote speeches and a sufficient amount of time for informal discussion amongst the participants. One of the most valuable aspects of the workshop was the opportunity for participants to meet informally and to discuss their mutual interests. This led to two "participant organized" sessions on five axis machining and on machine tool controllers.

This book offers a comprehensive introduction to Subdivision Surface Modeling Technology focusing not only on fundamental theories but also on practical applications. It furthers readers’ understanding of the contacts between spline surfaces and subdivision surfaces, enabling them to master the Subdivision Surface Modeling Technology for analyzing subdivision surfaces. Subdivision surface modeling is a popular technology in the field of computer aided design (CAD) and computer graphics (CG) thanks to its ability to model meshes of any topology. The book also discusses some typical Subdivision Surface Modeling Technologies, such as interpolation, fitting, fairing, intersection, as well as trimming and interactive editing. It is a valuable tool, enabling readers to grasp the main technologies of subdivision surface modeling and use them in software development, which in turn leads to a better understanding of CAD/CG software operations.

The book is the complete introduction and applications guide to this new technology. This book introduces the reader to features and gives an overview of geometric modeling techniques, discusses the conceptual development of features as modeling entities, illustrates the use of features for a variety of engineering design applications, and develops a set of broad functional requirements and addresses high level design issues.