Solid Modeling In Computer Graphics

This book contains the papers presented at the international research sympo sium "Solid Modeling by Computers: From Theory to Applications," held at the General Motors Research Laboratories on September 25-27, 1983. This was the 28th syposium in aseries which the Research Laboratories began sponsor ing in 1957. Each symposium has focused on a topic that is both under active study at the Research Laboratories and is also of interest to the larger technical community. Solid modeling is still a very young research area, young even when com pared with other computer-related research fields. Ten years ago, few people recognized the importance of being able to create complete and unambiguous computer models of mechanical parts. Today there is wide recognition that computer representations of solids are aprerequisite for the automation of many engineering analyses and manufacturing applications. In September 1983, the time was ripe for a symposium on this subject. Re search had already demonstrated the efficacy of solid modeling as a tool in computer automated design and manufacturing, and there were significant re suIts wh ich could be presented at the symposium. Yet the field was still young enough that we could bring together theorists in solid modeling and practition ers applying solid modeling to other research areas in a group sm all enough to allow a stimulating exchange of ideas.

It is the view of the author that the streams of geometric and solid modeling are converging, and that as the importance of this convergence is anticipated and recognized, the need for the development of techniques to bridge the gap between the two becomes critical. This book is devoted to filling that need. "Geometric and Solid Modeling" deals with the concepts and tools needed to design and implement solid-modeling systems and their infrastructure and substrata, making this information remarkably accessible--to the novice as well as to the experienced designer. The essential algorithms and the underlying theory needed to design these systems are given primary emphasis. Techniques for the study and implementation of geometric algorithms are taken from computer science, numerical analysis, and symbolic computation, among other areas. Special attention is given to geometric investigations of implicit and parametric surfaces, with the focal point being the possible integration of geometric and solid modeling.

In the history of technology, many fields have passed from an initial stage of empirical recipes to a mature stage where work is based on formal theories and procedures. This transition is made possible through a process called "modeling". Also Computer Graphics as a separate field of Computer Science makes extensive use of formal theories and procedures of modeling, often derived from related disciplines such as mathematics and physics. Modeling makes different application results consistent, unifying varieties of techniques and formal approaches into a smaller number of models by generalizing and abstracting the knowledge in Computer Graphics. This volume presents a selection of research papers submitted to the conference "Modeling in Computer Graphics: Methods and Applications" held at the Research Area of the National Research Council in Genoa, Italy, on June 28 -July 1, 1993. This meeting was the ideal continuation of a previous conference organized in Tokyo, Japan, in April 1991. The success and the variety of research themes discussed at that meeting suggested to promote a new working conference on methods and applications of modeling to be held in Italy two years later.

This book is a result of the lectures and discussions during the conference "Theory and Practice of Geometric Modeling". The event has been organized by the Wilhelm-Schickard-Institut fiir Informatik, Universitat Tiibingen and took place at the Heinrich-Fabri-Institut in Blaubeuren from October 3 to 7, 1988. The conference brought together leading experts from academic and industrial research institutions, CAD system developers and experien ced users to exchange their ideas and to discuss new concepts and future directions in geometric modeling. The main intention has been to bridge the gap between theoretical results, performance of existing CAD systems and the real problems of users. The contents is structured in five parts: A Algorithmic Aspects B Surface Intersection, Blending, Ray Tracing C Geometric Tools D Different Representation Schemes in Solid Modeling E Product Modeling in High Level Specifications The material presented in this book reflects the current state of the art in geometric modeling and should therefore be of interest not only to university and industry researchers, but also to system developers and practitioners who wish to keep up to date on recent advances and new concepts in this rapidly expanding field. The editors express their sincere appreciation to the contributing authors, and to the members of the program committee, W. Boehm, J. Hoschek, A. Massabo, H. Nowacki, M. Pratt, J. Rossignac, T. Sederberg and W. Tiller, for their close cooperation and their time and effort that made the conference and this book a success.

In the third paper in this chapter, Mike Pratt provides an historical intro duction to solid modeling. He presents the development of the three most freqently used techniques: cellular subdivision, constructive solid modeling and boundary representation. Although each of these techniques devel oped more or less independently, today the designer's needs dictate that a successful system allows access to all of these methods. For example, sculptured surfaces are generally represented using a boundary represen tation. However, the design of a complex vehicle generally dictates that a sculptured surface representation is most efficient for the 'skin' while constructive solid geometry representation is most efficent for the inter nal mechanism. Pratt also discusses the emerging concept of design by 'feature line'. Finally, he addresses the very important problem of data exchange between solid modeling systems and the progress that is being made towards developing an international standard. With the advent of reasonably low cost scientific workstations with rea sonable to outstanding graphics capabilities, scientists and engineers are increasingly turning to computer analysis for answers to fundamental ques tions and to computer graphics for present~tion of those answers. Although the current crop of workstations exhibit quite impressive computational ca pability, they are still not capable of solving many problems in a reasonable time frame, e. g. , executing computational fluid dynamics and finite element codes or generating complex ray traced or radiosity based images. In the sixth chapter Mike Muuss of the U. S.

This book is a collection of the best papers originally presented as state-of-the-art reports or tutorials at the Eurographics '91 conference in Vienna. A choice has been made giving priority to timeless information. Another goal was to cover all aspects of computer graphics - except hardware - as completely as possible from modelling to advanced visualization and communication. The ten contributions by internationally renowned experts fulfil this goal perfectly. Some important problem areas treated from different viewpoints thus enhancing and deepening the reader's perspective.

"Advances in computer technology and developments such as the Internet provide a constant momentum to design new techniques and algorithms to support computer graphics. Modelling, animation and rendering remain principal topics in the filed of computer graphics and continue to attract researchers around the world." This volume contains the papers presented at Computer Graphics International 2002, in July, at the University of Bradford, UK. These papers represent original research in computer graphics from around the world and cover areas such as: - Real-time computer animation - Image based rendering - Non photo-realistic rendering - Virtual reality - Avatars - Geometric and solid modelling - Computational geometry - Physically based modelling - Graphics hardware architecture - Data visualisation - Data compression The focus is on the commercial application and industrial use of computer graphics and digital media systems.