Rae Earnshaw – författare

State of the Art in Computer Graphics Aspects of Visualization This is the fourth volume derived from a State of . . . the Art in Computer Graphics Summer Institute. It represents a snapshot of a number of topics in computer graphics, topics which include visualization of scientific data; modeling; some aspects of visualization in virtual reality; and hardware architectures for visu­ alization. Many papers first present a background introduction to the topic, followed by discussion of current work in the topic. The volume is thus equally suitable for nonspecialists in a particular area, and for the more experienced researcher in the field. It also enables general readers to obtain an acquaintance with a particular topic area sufficient to apply that knowledge in the context of solving current problems. The volume is organized into four chapters - Visualization of Data, Modeling, Virtual Reality Techniques, and Hardware Architectures for Visualization. In the first chapter, Val Watson and Pamela Walatka address the visual aspects of fluid dynamic computations. They discuss algorithms for function-mapped surfaces and cutting planes, isosurfaces, particle traces, and topology extractions. They point out that current visualization systems are limited by low information transfer bandwidth, poor response to viewing and model accuracy modification requests, mismatches between model rendering and human cognitive capabilities, and ineffective interactive tools. However, Watson and Walatka indicate that proposed systems will correct most of these problems.

Review Office automation and associated hardware and software technologies are producing significant changes in traditional typing, printing, and publishing techniques and strategies. The long term impact of current developments is likely to be even more far reaching as reducing hardware costs, improved human-computer interfacing, uniformity through standardization, and sophisticated software facilities will all combine together to provide systems of power, capability and flexibility. The configuration of the system can be matched to the requirements of the user, whether typist, clerk, secretary, scientist, manager, director, or publisher. Enormous advances are currently being made in the areas of publication systems in the bringing together of text and pictures, and the aggregation of a greater variety of multi-media documents. Advances in technology and reductions in cost and size have produced many 'desk-top' publishing systems in the market place. More sophisticated systems are targeted at the high end of the market for newspaper production and quality color output. Outstanding issues in desk-top publishing systems include interactive editing of structured documents, integration of text and graphics, page description languages, standards, and the human-computer interface to documentation systems. The latter area is becoming increasingly important: usability by non-specialists and flexibility across application areas are two current concerns. One of the objectives of current work is to bring the production of high quality documents within the capability of naive users as well as experts.

The collection of papers that makes up this book arises largely from the joint activities of two specialist groups of the British Computer Society, namely the Displays Group and the Computer Arts Society. Both these groups are now more than 20 years old and during the whole of this time have held regular, separate meetings. In recent years, however, the two groups have held a joint annual meeting at which presentations of mutual interest have been given and it is mainly from the last two of these that the present papers have been drawn. They fall naturally into four classes: visualisation, art, design and animation-although, as in all such cases, the boundaries between the classes are fuzzy and overlap inevitably occurs. Visualisation The graphic potential of computers has been recognised almost since computing was first used, but it is only comparatively recently that their possibilities as devices for the visualisation of complex. and largely ab­ stract phenomena has begun to be more fully appreciated. Some workers stress the need to be able to model photographic reality in order to assist in this task. They look to better algorithms and more resolution to achieve this end. Others-Alan Mackay for instance-suggest that it is "not just a matter of providing more and more pixels. It is a matter of providing congenial clues which employ to the greatest extent what we already know.

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.

Today one of the hardest parts of computer aided design or analysis is first modeling the design, then recording and verifying it. For example, a typical vehicle such as a tank, automobile, ship or aircraft might be composed of tens of thousands of individual parts. Many of these parts are composed of cylinders, flats, and simple conic curves and surfaces such as are amenable to modeling using a constructive solid geometry (CSG) approach. However, especially with the increasing use of composite materials, many parts are designed using sculp­ tured surfaces. A marriage of these two techniques in now critical to continued development of computer aided design and analysis. Further, the graphical user interfaces used in most modeling systems are at best barely adequate to the required task. Critical work on these interfaces is required to continue pushing back the frontiers. Similarly, once the design is modeled, how are the varied and diverse pieces stored, retrieved, and modified? How are physical interferences prevented or eliminated? Although considerable progress has been made, there are still more questions and frustrations than answers. One of the fundamental problems of the 1990s is and will continue to be modeling. The second problem is interpretation. With the ever increasing computational power available, our ability to generate data far exceeds our ability to interpret, understand, and utilize that data.

"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.

Rae Earnshawand John A. Vince --_. . _----- 1 Introduction The USPresident''s Information Technology Advisory Committee (PITAC)recently advised the US Senate of the strategic importance of investing in IT for the 21st century, particularlyin the areas of software,human-computer interaction, scalable information infrastructure, high-end computing and socioeconomic issues [1]. Research frontiers ofhuman-computer interaction include the desire that interac­ tion be more centered around human needs and capabilities, and that the human environment be considered in virtual environments and in other contextual infor­ mation-processing activities. The overall goal is to make users more effective in their information or communication tasks by reducing learning times, speeding performance, lowering error rates, facilitating retention and increasing subjective satisfaction. Improved designs can dramatically increase effectiveness for users, who range from novices to experts and who have diverse cultures with varying educational backgrounds. Their lives could be made more satisfying, their work safer, their learning easier and their health better.

The very word "digital" has acquired a status that far exceeds its humble dictionary definition. Even the prefix digital, when associ­ ated with familiar sectors such as radio, television, photography and telecommunications, has reinvented these industries, and provided a unique opportunity to refresh them with new start-up companies, equipment, personnel, training and working practices - all of which are vital to modern national and international economies. The last century was a period in which new media stimulated new job opportunities, and in many cases created totally new sectors: video competed with film, CDs transformed LPs, and computer graphics threatened traditional graphic design sectors. Today, even the need for a physical medium is in question. The virtual digital domain allows the capture, processing, transmission, storage, retrieval and display of text, images, audio and animation without familiar materials such as paper, celluloid, magnetic tape and plastic. But moving from these media to the digital domain intro­ duces all sorts of problems, such as the conversion of analog archives, multimedia databases, content-based retrieval and the design of new content that exploits the benefits offered by digital systems. It is this issue of digital content creation that we address in this book. Authors from around the world were invited to comment on different aspects of digital content creation, and their contributions form the 23 chapters of this volume.

As the Internet and the WWW impact on corporate and private activities, the human-computer interface is becoming a central issue for the designers of these systems. Such interfaces will decide the success or failure of future technologies, which will have to provide users with easy-to-use ''intelligent'' problem solving tools.''Intelligent Agents'' are likely to play a significant role in the design of these interfaces, and this book explores how they are starting to influence media-based systems.As you read Intelligent Agents for Mobile and Virtual Media, you will discover the considerable advances that have already been made on the long journey towards a day when computers will be truly described as an intelligent aid to our personal and business lives.

Although the computer''s life has been relatively short, it has brought about an information revolution that is transforming our world on a scale that is still difficult to comprehend. This digital convergence is shaping society, technology and the media for the next millennium. Areas as diverse as home banking and shopping over the Internet; WWW access over mobile phone networks; and television systems such as Web TV which combine on-line services with television. But convergence is not just about technology. It is also about services and new ways of doing business and of interacting with society. Digital convergence heralds the ''Information Revolution''. Edited by John Vince and Rae Earnshaw this important new book on Digital Convergence: The Information Revolution is an edited volume of papers, bringing together state-of-the-art developments in the Internet and World Wide Web and should be compulsory reading for all those interested in and working in those areas.

_----- 1 Introduction The USPresident's Information Technology Advisory Committee (PITAC)recently advised the US Senate of the strategic importance of investing in IT for the 21st century, particularlyin the areas of software,human-computer interaction, scalable information infrastructure, high-end computing and socioeconomic issues [1].

The very word "digital" has acquired a status that far exceeds its humble dictionary definition. Even the prefix digital, when associ­ ated with familiar sectors such as radio, television, photography and telecommunications, has reinvented these industries, and provided a unique opportunity to refresh them with new start-up companies, equipment, personnel, training and working practices - all of which are vital to modern national and international economies. The last century was a period in which new media stimulated new job opportunities, and in many cases created totally new sectors: video competed with film, CDs transformed LPs, and computer graphics threatened traditional graphic design sectors. Today, even the need for a physical medium is in question. The virtual digital domain allows the capture, processing, transmission, storage, retrieval and display of text, images, audio and animation without familiar materials such as paper, celluloid, magnetic tape and plastic. But moving from these media to the digital domain intro­ duces all sorts of problems, such as the conversion of analog archives, multimedia databases, content-based retrieval and the design of new content that exploits the benefits offered by digital systems. It is this issue of digital content creation that we address in this book. Authors from around the world were invited to comment on different aspects of digital content creation, and their contributions form the 23 chapters of this volume.

"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.

As the Internet and the WWW impact on corporate and private activities, the human-computer interface is becoming a central issue for the designers of these systems. Such interfaces will decide the success or failure of future technologies, which will have to provide users with easy-to-use 'intelligent' problem solving tools.'Intelligent Agents' are likely to play a significant role in the design of these interfaces, and this book explores how they are starting to influence media-based systems.As you read Intelligent Agents for Mobile and Virtual Media, you will discover the considerable advances that have already been made on the long journey towards a day when computers will be truly described as an intelligent aid to our personal and business lives.

Although the computer's life has been relatively short, it has brought about an information revolution that is transforming our world on a scale that is still difficult to comprehend. This digital convergence is shaping society, technology and the media for the next millennium. Areas as diverse as home banking and shopping over the Internet; WWW access over mobile phone networks; and television systems such as Web TV which combine on-line services with television. But convergence is not just about technology. It is also about services and new ways of doing business and of interacting with society. Digital convergence heralds the 'Information Revolution'. Edited by John Vince and Rae Earnshaw this important new book on Digital Convergence: The Information Revolution is an edited volume of papers, bringing together state-of-the-art developments in the Internet and World Wide Web and should be compulsory reading for all those interested in and working in those areas.

The field of computer graphics combines display hardware, software, and interactive techniques in order to display and interact with data generated by applications. Visualization is concerned with exploring data and information graphically in such a way as to gain information from the data and determine significance. Visual analytics is the science of analytical reasoning facilitated by interactive visual interfaces.Expanding the Frontiers of Visual Analytics and Visualization provides a review of the state of the art in computer graphics, visualization, and visual analytics by researchers and developers who are closely involved in pioneering the latest advances in the field. It is a unique presentation of multi-disciplinary aspects in visualization and visual analytics, architecture and displays, augmented reality, the use of color, user interfaces and cognitive aspects, and technology transfer. It provides readers with insights into the latest developments in areas such as new displays and new display processors, new collaboration technologies, the role of visual, multimedia, and multimodal user interfaces, visual analysis at extreme scale, and adaptive visualization.

This volume presents state-of-the-art research from a wide area of subjects brought about by the digital convergence of computing, television, telecommunications and the World-Wide Web. It represents a unique snapshot of trends across a wide range of subjects including virtual environments; virtual reality; telepresence; human-computer interface design; interactivity; avatars; and the Internet. Both researchers and practitioners will find it an invaluable source of reference.

The field of computer graphics combines display hardware, software, and interactive techniques in order to display and interact with data generated by applications. Visualization is concerned with exploring data and information graphically in such a way as to gain information from the data and determine significance. Visual analytics is the science of analytical reasoning facilitated by interactive visual interfaces.Expanding the Frontiers of Visual Analytics and Visualization provides a review of the state of the art in computer graphics, visualization, and visual analytics by researchers and developers who are closely involved in pioneering the latest advances in the field. It is a unique presentation of multi-disciplinary aspects in visualization and visual analytics, architecture and displays, augmented reality, the use of color, user interfaces and cognitive aspects, and technology transfer. It provides readers with insights into the latest developments in areas such as new displays and new display processors, new collaboration technologies, the role of visual, multimedia, and multimodal user interfaces, visual analysis at extreme scale, and adaptive visualization.

This volume is based upon the presentations made at an international conference in London on the subject of ''Fractals and Chaos''. The objective of the conference was to bring together some of the leading practitioners and exponents in the overlapping fields of fractal geometry and chaos theory, with a view to exploring some of the relationships between the two domains. Based on this initial conference and subsequent exchanges between the editors and the authors, revised and updated papers were produced. These papers are contained in the present volume. We thank all those who contributed to this effort by way of planning and organisation, and also all those who helped in the production of this volume. In particular, we wish to express our appreciation to Gerhard Rossbach, Computer Science Editor, Craig Van Dyck, Production Director, and Nancy A. Rogers, who did the typesetting. A. J. Crilly R. A. Earnshaw H. Jones 1 March 1990 Introduction Fractals and Chaos The word ''fractal'' was coined by Benoit Mandelbrot in the late 1970s, but objects now defined as fractal in form have been known to artists and mathematicians for centuries. Mandelbrot''s definition-"a set whose Hausdorff dimension is not an integer" -is clear in mathematical terms. In addition, related concepts are those of self-similarity and sub-divisibility. A fractal object is self-similar in that subsections of the object are similar in some sense to the whole object.

State of the Art in Computer Graphics Aspects of Visualization This is the fourth volume derived from a State of . . . the Art in Computer Graphics Summer Institute. It represents a snapshot of a number of topics in computer graphics, topics which include visualization of scientific data; modeling; some aspects of visualization in virtual reality; and hardware architectures for visu­ alization. Many papers first present a background introduction to the topic, followed by discussion of current work in the topic. The volume is thus equally suitable for nonspecialists in a particular area, and for the more experienced researcher in the field. It also enables general readers to obtain an acquaintance with a particular topic area sufficient to apply that knowledge in the context of solving current problems. The volume is organized into four chapters - Visualization of Data, Modeling, Virtual Reality Techniques, and Hardware Architectures for Visualization. In the first chapter, Val Watson and Pamela Walatka address the visual aspects of fluid dynamic computations. They discuss algorithms for function-mapped surfaces and cutting planes, isosurfaces, particle traces, and topology extractions. They point out that current visualization systems are limited by low information transfer bandwidth, poor response to viewing and model accuracy modification requests, mismatches between model rendering and human cognitive capabilities, and ineffective interactive tools. However, Watson and Walatka indicate that proposed systems will correct most of these problems.

The collection of papers that makes up this book arises largely from the joint activities of two specialist groups of the British Computer Society, namely the Displays Group and the Computer Arts Society. Both these groups are now more than 20 years old and during the whole of this time have held regular, separate meetings. In recent years, however, the two groups have held a joint annual meeting at which presentations of mutual interest have been given and it is mainly from the last two of these that the present papers have been drawn. They fall naturally into four classes: visualisation, art, design and animation-although, as in all such cases, the boundaries between the classes are fuzzy and overlap inevitably occurs. Visualisation The graphic potential of computers has been recognised almost since computing was first used, but it is only comparatively recently that their possibilities as devices for the visualisation of complex. and largely ab­ stract phenomena has begun to be more fully appreciated. Some workers stress the need to be able to model photographic reality in order to assist in this task. They look to better algorithms and more resolution to achieve this end. Others-Alan Mackay for instance-suggest that it is "not just a matter of providing more and more pixels. It is a matter of providing congenial clues which employ to the greatest extent what we already know.

Review Office automation and associated hardware and software technologies are producing significant changes in traditional typing, printing, and publishing techniques and strategies. The long term impact of current developments is likely to be even more far reaching as reducing hardware costs, improved human-computer interfacing, uniformity through standardization, and sophisticated software facilities will all combine together to provide systems of power, capability and flexibility. The configuration of the system can be matched to the requirements of the user, whether typist, clerk, secretary, scientist, manager, director, or publisher. Enormous advances are currently being made in the areas of publication systems in the bringing together of text and pictures, and the aggregation of a greater variety of multi-media documents. Advances in technology and reductions in cost and size have produced many ''desk-top'' publishing systems in the market place. More sophisticated systems are targeted at the high end of the market for newspaper production and quality color output. Outstanding issues in desk-top publishing systems include interactive editing of structured documents, integration of text and graphics, page description languages, standards, and the human-computer interface to documentation systems. The latter area is becoming increasingly important: usability by non-specialists and flexibility across application areas are two current concerns. One of the objectives of current work is to bring the production of high quality documents within the capability of naive users as well as experts.

This volume is based upon the presentations made at an international conference in London on the subject of 'Fractals and Chaos'. The objective of the conference was to bring together some of the leading practitioners and exponents in the overlapping fields of fractal geometry and chaos theory, with a view to exploring some of the relationships between the two domains. Based on this initial conference and subsequent exchanges between the editors and the authors, revised and updated papers were produced. These papers are contained in the present volume. We thank all those who contributed to this effort by way of planning and organisation, and also all those who helped in the production of this volume. In particular, we wish to express our appreciation to Gerhard Rossbach, Computer Science Editor, Craig Van Dyck, Production Director, and Nancy A. Rogers, who did the typesetting. A. J. Crilly R. A. Earnshaw H. Jones 1 March 1990 Introduction Fractals and Chaos The word 'fractal' was coined by Benoit Mandelbrot in the late 1970s, but objects now defined as fractal in form have been known to artists and mathematicians for centuries. Mandelbrot's definition-"a set whose Hausdorff dimension is not an integer" -is clear in mathematical terms. In addition, related concepts are those of self-similarity and sub-divisibility. A fractal object is self-similar in that subsections of the object are similar in some sense to the whole object.

State of the Art in Computer Graphics Aspects of Visualization This is the fourth volume derived from a State of . . . the Art in Computer Graphics Summer Institute. It represents a snapshot of a number of topics in computer graphics, topics which include visualization of scientific data; modeling; some aspects of visualization in virtual reality; and hardware architectures for visu­ alization. Many papers first present a background introduction to the topic, followed by discussion of current work in the topic. The volume is thus equally suitable for nonspecialists in a particular area, and for the more experienced researcher in the field. It also enables general readers to obtain an acquaintance with a particular topic area sufficient to apply that knowledge in the context of solving current problems. The volume is organized into four chapters - Visualization of Data, Modeling, Virtual Reality Techniques, and Hardware Architectures for Visualization. In the first chapter, Val Watson and Pamela Walatka address the visual aspects of fluid dynamic computations. They discuss algorithms for function-mapped surfaces and cutting planes, isosurfaces, particle traces, and topology extractions. They point out that current visualization systems are limited by low information transfer bandwidth, poor response to viewing and model accuracy modification requests, mismatches between model rendering and human cognitive capabilities, and ineffective interactive tools. However, Watson and Walatka indicate that proposed systems will correct most of these problems.

Today one of the hardest parts of computer aided design or analysis is first modeling the design, then recording and verifying it. For example, a typical vehicle such as a tank, automobile, ship or aircraft might be composed of tens of thousands of individual parts. Many of these parts are composed of cylinders, flats, and simple conic curves and surfaces such as are amenable to modeling using a constructive solid geometry (CSG) approach. However, especially with the increasing use of composite materials, many parts are designed using sculp­ tured surfaces. A marriage of these two techniques in now critical to continued development of computer aided design and analysis. Further, the graphical user interfaces used in most modeling systems are at best barely adequate to the required task. Critical work on these interfaces is required to continue pushing back the frontiers. Similarly, once the design is modeled, how are the varied and diverse pieces stored, retrieved, and modified? How are physical interferences prevented or eliminated? Although considerable progress has been made, there are still more questions and frustrations than answers. One of the fundamental problems of the 1990s is and will continue to be modeling. The second problem is interpretation. With the ever increasing computational power available, our ability to generate data far exceeds our ability to interpret, understand, and utilize that data.

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.

The collection of papers that makes up this book arises largely from the joint activities of two specialist groups of the British Computer Society, namely the Displays Group and the Computer Arts Society. Both these groups are now more than 20 years old and during the whole of this time have held regular, separate meetings. In recent years, however, the two groups have held a joint annual meeting at which presentations of mutual interest have been given and it is mainly from the last two of these that the present papers have been drawn. They fall naturally into four classes: visualisation, art, design and animation-although, as in all such cases, the boundaries between the classes are fuzzy and overlap inevitably occurs. Visualisation The graphic potential of computers has been recognised almost since computing was first used, but it is only comparatively recently that their possibilities as devices for the visualisation of complex. and largely ab­ stract phenomena has begun to be more fully appreciated. Some workers stress the need to be able to model photographic reality in order to assist in this task. They look to better algorithms and more resolution to achieve this end. Others-Alan Mackay for instance-suggest that it is "not just a matter of providing more and more pixels. It is a matter of providing congenial clues which employ to the greatest extent what we already know.