Cumincad : CUMINCAD Papers : Search Results

CumInCAD is a Cumulative Index about publications in Computer Aided Architectural Design
supported by the sibling associations ACADIA, CAADRIA, eCAADe, SIGraDi, ASCAAD and CAAD futures

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_id	6002
authors	Barduzzi, Ondina and Pascolo, Carlo
year	1986
title	CAD System (Computer Aided Design) for the Planning of the Territory, with Reference to the Automatical Estimate of Works of Urbanization
source	Teaching and Research Experience with CAAD [4th eCAADe Conference Proceedings] Rome (Italy) 11-13 September 1986, pp. 167-179
doi	https://doi.org/10.52842/conf.ecaade.1986.167
summary	Any applied research, no matter what discipline is concerned, needs affined and suitable tools; as regards the studies in the field of architecture and planning, the use of automatic systems of analysis, data ordering and comparison is of particular interest. The quickness of operations by means of computers and the corresponding graphical representation gives new possibilities for scientific work, once impossible, not certainly because of conceptual limits, but practically, for the limits of available tools. It is the wideness of applications of computers to be pointed out, for although studied for scientific reasons, their practical usefulness is often enormous. This has been generally verified. It guilts in particular for the CAD System, proposed and explained in this paper. The practical utility this and other systems from the same field have for the public administration, contractors and consultants is well known and therefore not necessary to be described further. The use of such systems is particularly convenient in those sectors where the graphical representation is the basic part of the production process.
series	eCAADe
last changed	2022/06/07 07:54

_id	8e02
authors	Brown, A.G.P. and Coenen, F.P.
year	2000
title	Spatial reasoning: improving computational efficiency
source	Automation in Construction 9 (4) (2000) pp. 361-367
summary	When spatial data is analysed the result is often very computer intensive: even by the standards of contemporary technologies, the machine power needed is great and the processing times significant. This is particularly so in 3-D and 4-D scenarios. What we describe here is a technique, which tackles this and associated problems. The technique is founded in the idea of quad-tesseral addressing; a technique, which was originally applied to the analysis of atomic structures. It is based on ideas concerning Hierarchical clustering developed in the 1960s and 1970s to improve data access time [G.M. Morton, A computer oriented geodetic database and a new technique on file sequencing, IBM Canada, 1996.], and on atomic isohedral (same shape) tiling strategies developed in the 1970s and 1980s concerned with group theory [B. Grunbaum, G.C. Shephard, Tilings and Patterns, Freeman, New York, 1987.]. The technique was first suggested as a suitable representation for GIS in the early 1980s when the two strands were brought together and a tesseral arithmetic applied [F.C. Holdroyd, The Geometry of Tiling Hierarchies, Ars Combanitoria 16B (1983) 211–244.; S.B.M. Bell, B.M. Diaz, F.C. Holroyd, M.J.J. Jackson, Spatially referenced methods of processing raster and vector data, Image and Vision Computing 1 (4) (1983) 211–220.; Diaz, S.B.M. Bell, Spatial Data Processing Using Tesseral Methods, Natural Environment Research Council, Swindon, 1986.]. Here, we describe how that technique can equally be applied to the analysis of environmental interaction with built forms. The way in which the technique deals with the problems described is first to linearise the three-dimensional (3-D) space being investigated. Then, the reasoning applied to that space is applied within the same environment as the definition of the problem data. We show, with an illustrative example, how the technique can be applied. The problem then remains of how to visualise the results of the analysis so undertaken. We show how this has been accomplished so that the 3-D space and the results are represented in a way which facilitates rapid interpretation of the analysis, which has been carried out.
series	journal paper
more	http://www.elsevier.com/locate/autcon
last changed	2003/05/15 21:22

_id	8db7
authors	Gero, John S., Radford, Antony D. and Rosenman, Michael A. (et al)
year	1986
title	Knowledge-based Building Design
source	CIB 86, Advanced Building Technology, Proceedings. 1986. vol. 1: pp. 93-102
summary	CADLINE has abstract only. The use of the right knowledge depends not only on its availability but also on the designer recognizing that it is needed. The great majority of failures in building design and construction come from the non-application of existing, recorded knowledge; the designer either could not find the right information, or never recognized that the existing basis for making design decisions was inadequate in a new context. This paper describes some work towards the development of knowledge-based computer-aided design tools in which the knowledge is explicit, explained and open to modification. The philosophy behind the work is that design is almost always better if it is based on better knowledge, and that knowledge should be linked as closely as possible to the design activity. Rather than rely on a theoretical discussion, the authors make some brief statements about the nature of such knowledge-based systems and then give some working examples from the Architectural Computing Unit in the University of Sydney
keywords	building, knowledge base, design, architecture, CAD
series	CADline
email
last changed	2003/06/02 13:58

_id	e65f
authors	Haines, Eric A. and Greenberg, Donald P.
year	1986
title	The Light Buffer: A Shadow-Testing Accelerator
source	IEEE Computer Graphics and Applications. September, 1986. vol. 6: pp. 6-16 : col. ill. includes bibliography
summary	In one area of computer graphics, realistic image synthesis, the ultimate goal is to produce a picture indistinguishable from a photograph of a real environment. A particularly powerful technique for simulating light reflection - an important element in creating this realism - is called ray tracing. This method produces images of excellent quality, but suffers from lengthy computation time that limits its practical use. This article presents a new method to reduce shadow testing time during ray tracing. The technique involves generating light buffers, each of which partitions the environment with respect to an individual light source. These partition descriptions are then used during shadow testing to quickly determine a small subset of objects that may have to be tested for intersection. The results of timing tests illustrate the beneficial performance of these techniques. The tests compare the standard ray-tracing algorithm to light buffers of varying resolution
keywords	realism, synthesis, ray tracing, algorithms, computer graphics, shadowing
series	CADline
last changed	2003/06/02 13:58

_id	a833
authors	Jong, M. de
year	1986
title	A Spatial Relational Reference Model (3RM)
source	Computer-Aided Architectural Design Futures [CAAD Futures Conference Proceedings / ISBN 0-408-05300-3] Delft (The Netherlands), 18-19 September 1985, pp. 85-91
summary	In this chapter we hope to provide the reader with an impression of the objective, framework and possibilities of 3RM in the construction industry. In Dutch, 3RM stands for 'Ruimtelijk Relationeel Referentie Model' (Spatial Relational Reference Model). The model could begin to be used as an information-bearer in the building industry within which the specific trade information for each of the building participants could be interrelated, including drafting symbolism, building costs, physical qualities and building regulations. In this way, the model can be used as a means to a more efficient running of the building process and enabling the integration of information, at project level, provided by various building participants. The project should be defined in the same way as is a typical architectural project, whereby the actual development as well as the project management is carried out by architects. For the time being, development is limited to integral use at the design stage, but it also offers sufficient expansion possibilities to be able to function as a new communications model throughout the complete building process. We shall first provide information as to the origin, the objective and the execution of the project. Thereafter, we shall attempt to state the theoretical information problem within the building industry and the solution to this offered through 3RM. Finally, we shall report upon the results of the first phase of the 3RM project.
series	CAAD Futures
last changed	1999/04/03 17:58

_id	sigradi2008_175
id	sigradi2008_175
authors	Knight, Terry; Larry Sass, Kenfield Griffith, Ayodh Vasant Kamath
year	2008
title	Visual-Physical Grammars
source	SIGraDi 2008 - [Proceedings of the 12th Iberoamerican Congress of Digital Graphics] La Habana - Cuba 1-5 December 2008
summary	This paper introduces new visual-physical design grammars for the design and manufacture of building assembly systems that provide visually rich, culturally resonant design variations for housing. The building systems are intended to be tailored for particular cultures and communities by incorporating vernacular, decorative design into the assembly design. Two complementary areas of computational design research are brought together in this work: shape grammars and digital fabrication. The visual or graphic aspects of the research are explored through shape grammars. The physical design and manufacturing aspects are explored through advanced digital design and fabrication technologies and, in particular, build on recent work on mono-material assemblies with interlocking components that can be fabricated with CNC machines and assembled easily by hand on-site (Sass, 2007). This paper describes the initial, proof-of-concept stage of this work: the development of an automated, visual-physical grammar for an assembly system based on a vernacular language of Greek meander designs. A shape grammar for the two-dimensional Greek meander language (Knight, 1986) was translated into a three-dimensional assembly system. The components of the system are uniquely designed, concrete “meander bricks” (Figure 1). The components have integrated alignment features so that they can be easily fitted and locked together manually without binding materials. Components interlock horizontally to form courses, and courses interlock vertically in different ways to produce a visual variety of meander walls. The assembly components were prototyped at desktop scale with a layered manufacturing machine to test their appearance after assembly and their potential for design variations (Figure 2). Components were then evaluated as full-scale concrete objects for satisfaction of physical constraints related to concrete forming and component strength. The automated grammar (computer program) for this system generates assembly design variations with complete CAD/CAM data for fabrication of components formed from layered, CNC cut molds. Using the grammar, a full-scale mockup of a corner wall section was constructed to assess the structural, material, and aesthetic feasibility of the system, as well as ease of assembly. The results of this study demonstrate clearly the potentials for embedding visual properties in structural systems. They provide the foundations for further work on assembly systems for complete houses and other small-scale structures, and grammars to generate them. In the long-term, this research will lead to new solutions for economical, easily manufactured housing which is especially critical in developing countries and for post-disaster environments. These new housing solutions will not only provide shelter but will also support important cultural values through the integration of familiar visual design features. The use of inexpensive, portable digital design and fabrication technologies will allow local communities to be active, cooperative participants in the design and construction of their homes. Beyond the specific context of housing, visual-physical grammars have the potential to positively impact design and manufacture of designed artifacts at many scales, and in many domains, particularly for artifacts where visual aesthetics need to be considered jointly with physical or material requirements and design customization or variation is important.
keywords	Shape grammar, digital fabrication, building assembly, mass customization, housing
series	SIGRADI
email
last changed	2016/03/10 09:54

_id	6960
authors	Langendorf, Richard
year	1986
title	Alternative Models of Architectural Practice: The Impact of Computers -- 1990 and 2000
source	ACADIA Workshop ‘86 Proceedings - Houston (Texas - USA) 24-26 October 1986, pp. 7-27
doi	https://doi.org/10.52842/conf.acadia.1986.007
summary	Though many architectural firms have only recently begun to use computers, and most firms still do not use computers for design, it is likely that by the turn of the century computers will have transformed architectural practice. First this paper assesses the likelihood of change by examining the potential use of computers in architectural practice, summarizing technology forecasts for computer hardware, software, and standards. -However, because there is an opportunity, architectural firms will not necessarily computerize. Next is a brief review of impediments to change and the process of organizational adaptation of new technology. Finally, the paper concludes with a number of forecasts in architectural practice in 1990 and 2000. A variety of professional practice options are defined, with the suggestion that there will be increasing experimentation and diversity within the profession. Finally, the implications of these changes are explored for architectural education.
series	ACADIA
last changed	2022/06/07 07:52

_id	c7e9
authors	Maver, T.W.
year	2002
title	Predicting the Past, Remembering the Future
source	SIGraDi 2002 - [Proceedings of the 6th Iberoamerican Congress of Digital Graphics] Caracas (Venezuela) 27-29 november 2002, pp. 2-3
summary	Charlas Magistrales 2There never has been such an exciting moment in time in the extraordinary 30 year history of our subject area, as NOW,when the philosophical theoretical and practical issues of virtuality are taking centre stage.The PastThere have, of course, been other defining moments during these exciting 30 years:• the first algorithms for generating building layouts (circa 1965).• the first use of Computer graphics for building appraisal (circa 1966).• the first integrated package for building performance appraisal (circa 1972).• the first computer generated perspective drawings (circa 1973).• the first robust drafting systems (circa 1975).• the first dynamic energy models (circa 1982).• the first photorealistic colour imaging (circa 1986).• the first animations (circa 1988)• the first multimedia systems (circa 1995), and• the first convincing demonstrations of virtual reality (circa 1996).Whereas the CAAD community has been hugely inventive in the development of ICT applications to building design, it hasbeen woefully remiss in its attempts to evaluate the contribution of those developments to the quality of the built environmentor to the efficiency of the design process. In the absence of any real evidence, one can only conjecture regarding the realbenefits which fall, it is suggested, under the following headings:• Verisimilitude: The extraordinary quality of still and animated images of the formal qualities of the interiors and exteriorsof individual buildings and of whole neighborhoods must surely give great comfort to practitioners and their clients thatwhat is intended, formally, is what will be delivered, i.e. WYSIWYG - what you see is what you get.• Sustainability: The power of «first-principle» models of the dynamic energetic behaviour of buildings in response tochanging diurnal and seasonal conditions has the potential to save millions of dollars and dramatically to reduce thedamaging environmental pollution created by badly designed and managed buildings.• Productivity: CAD is now a multi-billion dollar business which offers design decision support systems which operate,effectively, across continents, time-zones, professions and companies.• Communication: Multi-media technology - cheap to deliver but high in value - is changing the way in which we canexplain and understand the past and, envisage and anticipate the future; virtual past and virtual future!MacromyopiaThe late John Lansdown offered the view, in his wonderfully prophetic way, that ...”the future will be just like the past, onlymore so...”So what can we expect the extraordinary trajectory of our subject area to be?To have any chance of being accurate we have to have an understanding of the phenomenon of macromyopia: thephenomenon exhibitted by society of greatly exaggerating the immediate short-term impact of new technologies (particularlythe information technologies) but, more importantly, seriously underestimating their sustained long-term impacts - socially,economically and intellectually . Examples of flawed predictions regarding the the future application of information technologiesinclude:• The British Government in 1880 declined to support the idea of a national telephonic system, backed by the argumentthat there were sufficient small boys in the countryside to run with messages.• Alexander Bell was modest enough to say that: «I am not boasting or exaggerating but I believe, one day, there will bea telephone in every American city».• Tom Watson, in 1943 said: «I think there is a world market for about 5 computers».• In 1977, Ken Olssop of Digital said: «There is no reason for any individuals to have a computer in their home».The FutureJust as the ascent of woman/man-kind can be attributed to her/his capacity to discover amplifiers of the modest humancapability, so we shall discover how best to exploit our most important amplifier - that of the intellect. The more we know themore we can figure; the more we can figure the more we understand; the more we understand the more we can appraise;the more we can appraise the more we can decide; the more we can decide the more we can act; the more we can act themore we can shape; and the more we can shape, the better the chance that we can leave for future generations a trulysustainable built environment which is fit-for-purpose, cost-beneficial, environmentally friendly and culturally significactCentral to this aspiration will be our understanding of the relationship between real and virtual worlds and how to moveeffortlessly between them. We need to be able to design, from within the virtual world, environments which may be real ormay remain virtual or, perhaps, be part real and part virtual.What is certain is that the next 30 years will be every bit as exciting and challenging as the first 30 years.
series	SIGRADI
email
last changed	2016/03/10 09:55

_id	d790
authors	Nakamae, E., Harada, K. and Ishizaki, T.
year	1986
title	A montage method: the overlaying of the computer generated images onto a background phograph
source	Computer Graphics, no. 4:207-214
summary	A system of computer programs has been established to generate high quality montage image of considerable usefulness in architectural simulation which combine computer-generated images and photographed background pictures. Traditionally, there are two methods of creating architectural montages: (I) an artist paints new buildings onto a background scene usually generated photographically, and (2) a three-dlmensional scale model is created to simulate the whole landscape, and this model is then photographed. The montage method described here combines aspects of both traditional montage methods with significant improvement in accuracy and reduction of time and cost of preparation. Specifically, a digitized photograph is used as a background scene onto which is superimposed a 3D computer-generated image of a new building. The outstanding points of the new method are: (i) The shading and shadows of each computer generated image are calculated with higher accuracy, (ii) the fog effect is taken into account, and (iii) a new anti-aliasing technique improves the quality of the final montage image.
series	journal paper
last changed	2003/04/23 15:50

_id	8312
authors	Rasdorf, William J. and Wang, TsoJen E.
year	1986
title	CDIS: An Engineering Constraint Definition and Integrity Enforcement System for Relational Databases
source	Computers in Engineering International Conference Proceedings. 1986. American Society of Mechanical Engineers, vol. 2: pp. 273-280. CADLINE has abstract only
summary	Database management systems (DBMS) are an essential component of the computer integrated manufacturing (CIM) environment. A database management system provides a powerful functionality for the storage, management, and use of engineering data. It is lacking, however, in its ability to deal with engineering constraints. In the past, constraint checking was performed by application programs. More recently DBMS's have been incorporating into their structure specifications for enforcing a limited set of integrity constraints and the mechanisms for invoking them automatically. To ensure the correctness of engineering data, an effective constraint management capability must be incorporated into any proposed engineering DBMS. This paper demonstrates how this can be done, proposes a systematic way to classify constraints so that integrity can be maintained efficiently, and discusses a prototype called CDIS which implements the concepts. This paper uses the relational database model to represent both engineering data and engineering constraints. Data integrity is defined and its enforcement through the use of engineering constraints is described. Existing methods for handling constraints are discussed. A new model that enables the engineer to associate design constraints with a relational database is presented and an example is given that demonstrates the model. Extensions to a DBMS to implement the concepts presented are described. No currently available DBMS provides the much needed capabilities proposed here
keywords	civil engineering, relational database, constraints management
series	CADline
last changed	2003/06/02 13:58

_id	20a8
authors	Ruffle, Simon
year	1986
title	How Can CAD Provide for the Changing Role of the Architect?
source	Computer-Aided Architectural Design Futures [CAAD Futures Conference Proceedings / ISBN 0-408-05300-3] Delft (The Netherlands), 18-19 September 1985, pp. 197-199
summary	At the RIBA Conference of 1981 entitled 'New Opportunities', and more recently at the 1984 ACA Annual Conference on 'Architects in Competition' there has been talk of marketing, new areas of practice, recapturing areas of practice lost to other professions, more accountability to client and public 'the decline of the mystique of the professional'. It is these issues, rather than technical advances in software and hardware, that will be the prime movers in getting computers into widespread practice in the future. In this chapter we will examine how changing attitudes in the profession might affect three practical issues in computing with which the author has been preoccupied in the past year. We will conclude by considering how, in future, early design stage computing may need to be linked to architectural theory, and, as this is a conference where we are encouraged to be outspoken, we will raise the issue of a computer-based theory of architecture.
series	CAAD Futures
email
last changed	2003/05/16 20:58

_id	095b
authors	Wagter, Harry
year	1986
title	Stimulating Creativity by Using Computers
source	ACADIA Workshop ‘86 Proceedings - Houston (Texas - USA) 24-26 October 1986, pp. 149-155
doi	https://doi.org/10.52842/conf.acadia.1986.149
summary	Discussions that cope with the relation between computers and creativity often turn out to be very sensitive. It seems that this aspect of computer technology makes people feel uneasy. This can easily be understood. Many examples can be found were interesting jobs with social contacts for workers changed into dull and monotone ones. This counts specially for administrative oriented organisations, but also in more technical based organisations we can see variations to this theme. Nevertheless many advantages can be mentioned for the organisation itself, and of course for the customer himself, who is being served more accurate, faster and with a higher degree of service. The discussion on creative aspects mainly takes place in the technical oriented professions. Architects among them seem to be strongly represented. Specially in relation to CAD-techniques being obstructed in one's creative possibilities is very often mentioned as an argument for not adopting the new techniques.
series	ACADIA
email
last changed	2022/06/07 07:58

_id	69c7
authors	Woodbury, Robert F.
year	1986
title	VEGA : A Geometric Modelling System
source	11 p. : ill. Engineering Design Research Center, CMU, April 1986. DRC-48-03-87. includes bibliography
summary	VEGA is a program which models rigid solid objects in three dimensions. Specifically, its domain is assemblies of planar faced polyhedra. VEGA supports a variety of operations to create, modify, query and delete these assemblies. VEGA is intended to serve two purposes: that of a new medium of representation for the design process; and of a programming package to support geometric applications in a wide variety of domains. Here the author addresses primarily the first of these purposes, that of a new medium for design. Designers of physical objects use an external medium, traditionally paper or physical models, not only to record their work, but to provide information which assists in the understanding of implications of design decisions. Designers proceed by performing operations, which reflect internal design decisions, on this external medium. The operations used in design are generally reflective of these physical media. For example, models built of clay tend to be formed by a subtractive processes, whereas models built of wood tend to be additive in nature. Designers who use drawings as their medium still tend to use operations which reflect operations on physical models. Computers provide the fascinating potential to provide a much wider variety of operations at a much greater speed than is available with the traditional means of representation. In addition, a computer based representation can provide quantitative information not easily accessible from traditional forms. This opens the potential for the inclusion of formal means of evaluation in the design process; something which is generally almost absent in traditional design teaching. A computer program which effectively and 'naturally' models physical objects and operations on them would be a valuable assistance to both the teaching and practice design. VEGA has been designed with these objectives in mind. VEGA represents physical objects with a scheme known as boundary representation and provides a wide variety of operations on these objects. VEGA also provides means to associate other, non-geometric, information with the objects it represents. VEGA is implemented under the ANDREW system. It communicates to ANDREW through a graphics package, also developed by the author's group. VEGA is intended to serve as a medium for future studio courses in the Architecture, Industrial Design and Arts education
keywords	geometric modeling, solid modeling, CAD, education, assemblies, B-rep, systems
series	CADline
email
last changed	2003/06/02 10:24

_id	2fc1
authors	Zdepski, M. Stephen and Goldman, Glen
year	1986
title	The Computability of Design
source	ACADIA Workshop ‘86 Proceedings - Houston (Texas - USA) 24-26 October 1986, pp. 103-111
doi	https://doi.org/10.52842/conf.acadia.1986.103
summary	A number of architectural design studios (second, third and fifth year) at the School of Architecture at the New Jersey Institute of Technology have undertaken traditional design problems through the use of IBM-AT microcomputer based CAD/Graphics systems. Utilizing three-dimensional modeling software, color graphics "paint" software, and animation software, the studios integrated the use of computers into the very heart of the core program as the primary means of design, simulation, and evaluation. At the same time, other non-computer based studios engaged in similar (and often identical) design problems. Therefore, the opportunity became available to compare and evaluate both the impact the computer made to the traditional architectural studio and also to the building design itself.
series	ACADIA
email
last changed	2022/06/07 07:57

_id	242d
authors	Atkin, Brian L. and Gill, E. Moira
year	1986
title	CAD and Management of Construction Projects
source	Journal of Construction Engineering and Management, Vol. 112, December, pp. 557-565
summary	The increasing interest in computer-aided design (CAD) has prompted research that is aimed at identifying the opportunities for construction managers and building contractors. It has been found that the use of CAD systems in the U.K. is mainly confined to the production of detailed drawings. Indeed, most of the systems used are 2-D drafting tools and incapable of supporting the integration of even modest amounts of nongraphical (construction) data. On the other hand, many 3-D modeling systems have the potential to integrate construction data, although they appear to be almostignored. The use of 3-D modeling systems is considered to be the most suitable vehicle for successfully integrating these data. However, this is likely to necessitate the introduction of separate databases, preferably of the relational type. The use of 3-D modeling systems in assessing the construction implications of outline designs also presents interesting possibilities and is discussed.
series	journal paper
last changed	2003/04/23 15:14

_id	6c8e
authors	Barbera, Salvatore and Correnti, Gabriele
year	1986
title	Reticular and Linear Planning of Erecting Yards Aided by Personal Computer
source	Teaching and Research Experience with CAAD [4th eCAADe Conference Proceedings] Rome (Italy) 11-13 September 1986, pp. 157-166
doi	https://doi.org/10.52842/conf.ecaade.1986.157
summary	This study has been carried out during the Course of Ergotecnica Edile hold at the Instituto Dipartimentale di Architettura e Urbanistica of Catania University, and it has been addressed to the students of the Faculty of Civil Engineering (manufacturing and direction of civil works). The present study aims at instructing the students as refers to planning, through computers, erecting yards. Work-planning is specifically important with reference both to the starting program and to the carrying on of the work. Within this context, workplanning is useful as regard the control and contingent correction of the work. In the latter case, divergencies between work-evolution and forecast are of primary value.
series	eCAADe
last changed	2022/06/07 07:54

_id	aec8
authors	Bellinghall, Leigh
year	1986
title	The MicroCad Explosion : An Eye to Applications Clarifies Choices
source	computer Graphics World March, 1986. vol. 9: pp. 23-28 : col. ill.
summary	Two strong trends affirm increasing market interest in micro systems. While early programs were developed for personal computers, turnkey system houses are now stretching heavy-duty mini and mainframe-hosted programs down to micros. This article gives a selective survey of popular micro-CAD software, looks at packages in both development areas
keywords	drafting, systems, CAD, software, applications
series	CADline
last changed	1999/02/12 15:07

_id	ed51
authors	Bergeron, Philippe
year	1986
title	A General Version of Crow's Shadow Volumes
source	IEEE Computer Graphics and Applications September, 1986. vol. 6: pp. 17-28 : col. ill. includes bibliography.
summary	In 1977 Frank Crow introduced a new class of algorithms for the generation of shadows. His technique, based on the concept of shadow volumes, assumes a polygonal database and a constrained environment. For example, polyhedrons must be closed, and polygons must be planar. This article presents a new version of Crow's algorithm, developed at the Universite de Montreal, which attempts a less constrained environment. The method has allowed the handling of both open and closed models and nonplanar polygons with the viewpoint anywhere, including any shadow volume. It does not, however, sacrifice the essential features of Crow's original version: penetration between polygons is allowed, and any number of light sources can be defined anywhere in 3D space, including the view volume and any shadow volume. The method has been used successfully in the film Tony de Peltrie and is easily incorporated into an existing scan-line, hidden-surface algorithm
keywords	algorithms, shadowing, polygons, computer graphics
series	CADline
last changed	1999/02/12 15:07

_id	6733
authors	Bettels, Juergen and Myers, David R.
year	1986
title	The PIONS Graphics System
source	IEEE Computer Graphics and Applications. July, 1986. vol. 6: pp. 30-38 : col. ill. includes a short bibliography
summary	During 1979, CERN began to evaluate how interactive computer graphics displays could aid the analysis of high-energy physics experiments at the new Super Proton Synchrotron collider. This work led to PIONS, a 3D graphics system, which features the ability to store and view hierarchical graphics structures in a directed-acyclic-graph database. It is possible to change the attributes of these structures by making selections on nongraphical information also stored in the database. PIONS is implemented as an object-oriented message-passing system based on SmallTalk design principles. It supports multiple viewing transformations, logical input devices, and 2D and 3D primitives. The design allows full use to be made of display hardware that provides dynamic 3D picture transformation
keywords	visualization, computer graphics, database, systems, modeling
series	CADline
last changed	2003/06/02 13:58

_id	a7de
authors	Bic, Lubomir and Jonathan P. Gilbert
year	1986
title	Learning from AI : New Trends in Database Technology
source	IEEE Computer. March, 1986. vol. 19: pp. 44-54. includes bibliography
summary	With the steadily increasing demand for user-oriented systems, new trends in database technology have evolved outside of the scope of the traditional data models. The authors are concentrated in this article on two closely related efforts: The incorporation of more semantic modeling capabilities into database models, and the development of better user environment, which include user friendly interfaces and support different user views of the content and organization of the data
keywords	AI, user interface, database, relational database
series	CADline
last changed	1999/02/12 15:07

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