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	9fcb
authors	Steele, Guy Lewis
year	1980
title	The Definition and Implementation of a Computer Programming Language Based Constraints
source	MIT - AITR-595
summary	The constraint paradigm is a model of computation in which values are deduced whenever possible, under the limitation that deductions be local in a certain sense. One may visualize a constraint 'program' as a network of devices connected by wires. Data values may flow along the wires, and computation is performed by the devices. A device computes using only locally available information (with a few exceptions), and places newly derived values on other, locally attached wires. In this way computed values are propagated. An advantage of the constraint paradigm (not unique to it) is that a single relationship can be used in more than one direction. The connections to a device are not labelled as inputs and outputs; a device will compute with whatever values are available, and produce as many new values as it can. General theorem provers are capable of such behavior, but tend to suffer from combinatorial explosion; it is not usually useful to derive all the possible consequences of a set of hypotheses. The constraint paradigm places a certain kind of limitation on the deduction process. The limitations imposed by the constraint paradigm are not the only one possible. It is argued, however, that they are restrictive enough to forestall combinatorial explosion in many interesting computational situations, yet permissive enough to allow useful computations in practical situations. Moreover, the paradigm is intuitive: It is easy to visualize the computational effects of these particular limitations, and the paradigm is a natural way of expressing programs for certain applications, in particular relationships arising in computer-aided design. A number of implementations of constraint-based programming languages are presented. A progression of ever more powerful languages is described, complete implementations are presented and design difficulties and alternatives are discussed. The goal approached, though not quite reached, is a complete programming system which will implicitly support the constraint paradigm to the same extent that LISP, say, supports automatic storage management.
series	thesis:PhD
email
more	ftp://publications.ai.mit.edu/ai-publications/pdf/AITR-595.pdf
last changed	2003/02/12 22:37

_id	cdc2008_243
id	cdc2008_243
authors	Loukissas, Yanni
year	2008
title	Keepers of the Geometry: Architects in a Culture of Simulation
source	First International Conference on Critical Digital: What Matters(s)? - 18-19 April 2008, Harvard University Graduate School of Design, Cambridge (USA), pp. 243-244
summary	“Why do we have to change? We’ve been building buildings for years without CATIA?” Roger Norfleet, a practicing architect in his thirties poses this question to Tim Quix, a generation older and an expert in CATIA, a computer-aided design tool developed by Dassault Systemes in the early 1980’s for use by aerospace engineers. It is 2005 and CATIA has just come into use at Paul Morris Associates, the thirty-person architecture firm where Norfleet works; he is struggling with what it will mean for him, for his firm, for his profession. Computer-aided design is about creativity, but also about jurisdiction, about who controls the design process. In Architecture: The Story of Practice, Architectural theorist Dana Cuff writes that each generation of architects is educated to understand what constitutes a creative act and who in the system of their profession is empowered to use it and at what time. Creativity is socially constructed and Norfleet is coming of age as an architect in a time of technological but also social transition. He must come to terms with the increasingly complex computeraided design tools that have changed both creativity and the rules by which it can operate. In today’s practices, architects use computer-aided design software to produce threedimensional geometric models. Sometimes they use off-the-shelf commercial software like CATIA, sometimes they customize this software through plug-ins and macros, sometimes they work with software that they have themselves programmed. And yet, conforming to Larson’s ideas that they claim the higher ground by identifying with art and not with science, contemporary architects do not often use the term “simulation.” Rather, they have held onto traditional terms such as “modeling” to describe the buzz of new activity with digital technology. But whether or not they use the term, simulation is creating new architectural identities and transforming relationships among a range of design collaborators: masters and apprentices, students and teachers, technical experts and virtuoso programmers. These days, constructing an identity as an architect requires that one define oneself in relation to simulation. Case studies, primarily from two architectural firms, illustrate the transformation of traditional relationships, in particular that of master and apprentice, and the emergence of new roles, including a new professional identity, “keeper of the geometry,” defined by the fusion of person and machine. Like any profession, architecture may be seen as a system in flux. However, with their new roles and relationships, architects are learning that the fight for professional jurisdiction is increasingly for jurisdiction over simulation. Computer-aided design is changing professional patterns of production in architecture, the very way in which professionals compete with each other by making new claims to knowledge. Even today, employees at Paul Morris squabble about the role that simulation software should play in the office. Among other things, they fight about the role it should play in promotion and firm hierarchy. They bicker about the selection of new simulation software, knowing that choosing software implies greater power for those who are expert in it. Architects and their collaborators are in a continual struggle to define the creative roles that can bring them professional acceptance and greater control over design. New technologies for computer-aided design do not change this reality, they become players in it.
email
last changed	2009/01/07 08:05

_id	ascaad2007_019
id	ascaad2007_019
authors	Morsy, S.M.
year	2007
title	A Social Approach to Intelligent Buildings
source	Em‘body’ing Virtual Architecture: The Third International Conference of the Arab Society for Computer Aided Architectural Design (ASCAAD 2007), 28-30 November 2007, Alexandria, Egypt, pp. 229-242
summary	Intelligent buildings were a hot topic since the 1980's. The vision was to share building telecommunication backbones with energy management systems, fire alarms, security systems and even office automation. The benefits were touted to include cost savings for cabling and long term maintenance, plus a future potential for interoperability between systems. The potential within these concepts and the surrounding technology is vast, and lives of users are changing from the effects of Intelligent Buildings developments on their living and working environments. In other words, the main aim of building intelligent building is merely a technological trend. But using intelligent buildings has wider effects on users than intended. Neglecting the human aspects of the users may be considered as a shortcoming. This paper considers the causes of this new trend in architecture in a larger social context, from which the rationalism of building intelligent buildings must arise. This will be done through exploring the concepts and applications of intelligent buildings, showing how all of them affect human life in such many ways.
series	ASCAAD
email
last changed	2008/01/21 22:00

_id	48db
authors	Proctor, George
year	2001
title	CADD Curriculum - The Issue of Visual Acuity
source	Architectural Information Management [19th eCAADe Conference Proceedings / ISBN 0-9523687-8-1] Helsinki (Finland) 29-31 August 2001, pp. 192-200
doi	https://doi.org/10.52842/conf.ecaade.2001.192
summary	Design educators attempt to train the eyes and minds of students to see and comprehend the world around them with the intention of preparing those students to become good designers, critical thinkers and ultimately responsible architects. Over the last eight years we have been developing the digital media curriculum of our architecture program with these fundamental values. We have built digital media use and instruction on the foundation of our program which has historically been based in physical model making. Digital modeling has gradually replaced the capacity of physical models as an analytical and thinking tool, and as a communication and presentation device. The first year of our program provides a foundation and introduction to 2d and 3d design and composition, the second year explores larger buildings and history, the third year explores building systems and structure through design studies of public buildings, fourth year explores urbanism, theory and technology through topic studios and, during the fifth year students complete a capstone project. Digital media and CADD have and are being synchronized with the existing NAAB accredited regimen while also allowing for alternative career options for students. Given our location in the Los Angeles region, many students with a strong background in digital media have gone on to jobs in video game design and the movie industry. Clearly there is much a student of architecture must learn to attain a level of professional competency. A capacity to think visually is one of those skills and is arguably a skill that distinguishes members of the visual arts (including Architecture) from other disciplines. From a web search of information posted by the American Academy of Opthamology, Visual Acuity is defined as an ability to discriminate fine details when looking at something and is often measured with the Snellen Eye Chart (the 20/20 eye test). In the context of this paper visual acuity refers to a subject’s capacity to discriminate useful abstractions in a visual field for the purposes of Visual Thinking- problem solving through seeing (Arnheim, 1969, Laseau 1980, Hoffman 1998). The growing use of digital media and the expanding ability to assemble design ideas and images through point-and-click methods makes the cultivation and development of visual skills all the more important to today’s crop of young architects. The advent of digital media also brings into question the traditional, static 2d methods used to build visual skills in a design education instead of promoting active 3d methods for teaching, learning and developing visual skills. Interactive digital movies provide an excellent platform for promoting visual acuity, and correlating the innate mechanisms of visual perception with the abstractions and notational systems used in professional discourse. In the context of this paper, pedagogy for building visual acuity is being considered with regard to perception of the real world, for example the visual survey of an environment, a site or a street scene and how that visual survey works in conjunction with practice.
keywords	Curriculum, Seeing, Abstracting, Notation
series	eCAADe
email
last changed	2022/06/07 08:00

_id	cf2011_p170
id	cf2011_p170
authors	Barros, Mário; Duarte José, Chaparro Bruno
year	2011
title	Thonet Chairs Design Grammar: a Step Towards the Mass Customization of Furniture
source	Computer Aided Architectural Design Futures 2011 [Proceedings of the 14th International Conference on Computer Aided Architectural Design Futures / ISBN 9782874561429] Liege (Belgium) 4-8 July 2011, pp. 181-200.
summary	The paper presents the first phase of research currently under development that is focused on encoding Thonet design style into a generative design system using a shape grammar. The ultimate goal of the work is the design and production of customizable chairs using computer assisted tools, establishing a feasible practical model of the paradigm of mass customization (Davis, 1987). The current research step encompasses the following three steps: (1) codification of the rules describing Thonet design style into a shape grammar; (2) implementing the grammar into a computer tool as parametric design; and (3) rapid prototyping of customized chair designs within the style. Future phases will address the transformation of the Thonet’s grammar to create a new style and the production of real chair designs in this style using computer aided manufacturing. Beginning in the 1830’s, Austrian furniture designer Michael Thonet began experimenting with forming steam beech, in order to produce lighter furniture using fewer components, when compared with the standards of the time. Using the same construction principles and standardized elements, Thonet produced different chairs designs with a strong formal resemblance, creating his own design language. The kit assembly principle, the reduced number of elements, industrial efficiency, and the modular approach to furniture design as a system of interchangeable elements that may be used to assemble different objects enable him to become a pioneer of mass production (Noblet, 1993). The most paradigmatic example of the described vision of furniture design is the chair No. 14 produced in 1858, composed of six structural elements. Due to its simplicity, lightness, ability to be stored in flat and cubic packaging for individual of collective transportation, respectively, No. 14 became one of the most sold chairs worldwide, and it is still in production nowadays. Iconic examples of mass production are formally studied to provide insights to mass customization studies. The study of the shape grammar for the generation of Thonet chairs aimed to ensure rules that would make possible the reproduction of the selected corpus, as well as allow for the generation of new chairs within the developed grammar. Due to the wide variety of Thonet chairs, six chairs were randomly chosen to infer the grammar and then this was fine tuned by checking whether it could account for the generation of other designs not in the original corpus. Shape grammars (Stiny and Gips, 1972) have been used with sucesss both in the analysis as in the synthesis of designs at different scales, from product design to building and urban design. In particular, the use of shape grammars has been efficient in the characterization of objects’ styles and in the generation of new designs within the analyzed style, and it makes design rules amenable to computers implementation (Duarte, 2005). The literature includes one other example of a grammar for chair design by Knight (1980). In the second step of the current research phase, the outlined shape grammar was implemented into a computer program, to assist the designer in conceiving and producing customized chairs using a digital design process. This implementation was developed in Catia by converting the grammar into an equivalent parametric design model. In the third phase, physical models of existing and new chair designs were produced using rapid prototyping. The paper describes the grammar, its computer implementation as a parametric model, and the rapid prototyping of physical models. The generative potential of the proposed digital process is discussed in the context of enabling the mass customization of furniture. The role of the furniture designer in the new paradigm and ideas for further work also are discussed.
keywords	Thonet; furniture design; chair; digital design process; parametric design; shape grammar
series	CAAD Futures
email
last changed	2012/02/11 19:21

_id	2fdd
authors	Barsky, Brian A. and Thomas, Spencer W.
year	1980
title	Transpline Curve Representation System
source	April, 1980. 19 p. : ill. includes bibliography
summary	An interactive curve representation system has been developed based on the concept of transforming among several parametric spline curve formulations. The available formulations are the interpolatory spline, uniform B-spline, spline under tension, and NU-spline. The system implementation is described in the context of a sample design session
keywords	computational geometry, curves, representation, splines
series	CADline
last changed	2003/06/02 13:58

_id	8629
authors	Barzilay, Amos
year	1980
title	Human Problem Solving on Master Mind
source	Carnegie Mellon University
summary	The purpose of this work is to analyze the task of playing Master Mind and to examine subjects behaviors on solving that task. The methods and the ideas that are used in the work are the same found in the references for other tasks. The author wants to show that those ideas and methods can be used for that specific task as well. In other words, subjects behave in such a domain as an information processing system. [includes bibliography]
keywords	Psychology, Problem Solving
series	CADline
last changed	1999/02/15 15:10

_id	e825
authors	Baybars, Ilker and Eastman, Charles M.
year	1980
title	Enumerating Architectural Arrangements by Generating Their Underlying Graphs
source	Environment and Planning B. 1980. vol. 7: pp. 289- 310 : ill. includes bibliography. -- See also 'Enumerating Architectural Arrangements: Comment on a Recent Paper by Baybars and Eastman' by C.F. Earl
summary	One mathematical correspondence to the partitioning of the plane is a Weighted Plane Graph (WPG). This paper first focuses on the systematic generation of WPGs, in a fashion similar to crystal growth. During this process, the WPGs are represented by adjacency matrices. The authors, thus, present a method for embedding the WPG in the plane, given its adjacency matrix. These graphs can, then, be mapped into floor plans. The common practice here is the use of the `geometric dual' of a WPG. The authors propose, instead, the use of the `Pseudogeometric dual' of a WPG directly to translate (part of) a design brief into alternative spatial layouts. Also discussed is the ability to create courtyards and/or circulation spaces given a specific WPG, without increasing the size of the problem
keywords	enumeration, architecture, floor plans, graphs, design process, automation, algorithms, space allocation, CAD
series	CADline
email
last changed	2003/05/17 10:15

_id	cf2011_p127
id	cf2011_p127
authors	Benros, Deborah; Granadeiro Vasco, Duarte Jose, Knight Terry
year	2011
title	Integrated Design and Building System for the Provision of Customized Housing: the Case of Post-Earthquake Haiti
source	Computer Aided Architectural Design Futures 2011 [Proceedings of the 14th International Conference on Computer Aided Architectural Design Futures / ISBN 9782874561429] Liege (Belgium) 4-8 July 2011, pp. 247-264.
summary	The paper proposes integrated design and building systems for the provision of sustainable customized housing. It advances previous work by applying a methodology to generate these systems from vernacular precedents. The methodology is based on the use of shape grammars to derive and encode a contemporary system from the precedents. The combined set of rules can be applied to generate housing solutions tailored to specific user and site contexts. The provision of housing to shelter the population affected by the 2010 Haiti earthquake illustrates the application of the methodology. A computer implementation is currently under development in C# using the BIM platform provided by Revit. The world experiences a sharp increase in population and a strong urbanization process. These phenomena call for the development of effective means to solve the resulting housing deficit. The response of the informal sector to the problem, which relies mainly on handcrafted processes, has resulted in an increase of urban slums in many of the big cities, which lack sanitary and spatial conditions. The formal sector has produced monotonous environments based on the idea of mass production that one size fits all, which fails to meet individual and cultural needs. We propose an alternative approach in which mass customization is used to produce planed environments that possess qualities found in historical settlements. Mass customization, a new paradigm emerging due to the technological developments of the last decades, combines the economy of scale of mass production and the aesthetics and functional qualities of customization. Mass customization of housing is defined as the provision of houses that respond to the context in which they are built. The conceptual model for the mass customization of housing used departs from the idea of a housing type, which is the combined result of three systems (Habraken, 1988) -- spatial, building system, and stylistic -- and it includes a design system, a production system, and a computer system (Duarte, 2001). In previous work, this conceptual model was tested by developing a computer system for existing design and building systems (Benr__s and Duarte, 2009). The current work advances it by developing new and original design, building, and computer systems for a particular context. The urgent need to build fast in the aftermath of catastrophes quite often overrides any cultural concerns. As a result, the shelters provided in such circumstances are indistinct and impersonal. However, taking individual and cultural aspects into account might lead to a better identification of the population with their new environment, thereby minimizing the rupture caused in their lives. As the methodology to develop new housing systems is based on the idea of architectural precedents, choosing existing vernacular housing as a precedent permits the incorporation of cultural aspects and facilitates an identification of people with the new housing. In the Haiti case study, we chose as a precedent a housetype called ‚Äúgingerbread houses‚Äù, which includes a wide range of houses from wealthy to very humble ones. Although the proposed design system was inspired by these houses, it was decided to adopt a contemporary take. The methodology to devise the new type was based on two ideas: precedents and transformations in design. In architecture, the use of precedents provides designers with typical solutions for particular problems and it constitutes a departing point for a new design. In our case, the precedent is an existing housetype. It has been shown (Duarte, 2001) that a particular housetype can be encoded by a shape grammar (Stiny, 1980) forming a design system. Studies in shape grammars have shown that the evolution of one style into another can be described as the transformation of one shape grammar into another (Knight, 1994). The used methodology departs takes off from these ideas and it comprises the following steps (Duarte, 2008): (1) Selection of precedents, (2) Derivation of an archetype; (3) Listing of rules; (4) Derivation of designs; (5) Cataloguing of solutions; (6) Derivation of tailored solution.
keywords	Mass customization, Housing, Building system, Sustainable construction, Life cycle energy consumption, Shape grammar
series	CAAD Futures
email
last changed	2012/02/11 19:21

_id	8a27
authors	Bentley, Jon L. and Carruthers, Wendy
year	1980
title	Algorithms for Testing the Inclusion of Points in Polygons
source	Allertorn Conference on Communication, Control and Computing (18th : 1980). (10) p. includes bibliography
summary	Determining whether a given point lies inside or outside a simple polygon is an important problem in many applications, including computer vision systems and computer-assisted political redistricting systems. In this paper the authors give algorithms for inclusion problems that are efficient for polygons that are 'close to convex' in a certain precise sense. An empirical study of polygons that arise in several applications shows that typical polygons are indeed 'close to convex,' and a program implementing the algorithm shows that is extremely efficient on point sets of practical sizes
keywords	point inclusion, polygons, algorithms, computational geometry
series	CADline
last changed	2003/06/02 13:58

_id	4580
authors	Borgerson, B. R. and Johnson, Robert H.
year	1980
title	Beyond CAD to Computer Aided Engineering
source	(8) p. : ill. Manufacturing Data Systems Incorporated, 1980? includes bibliography
summary	Current CAD systems significantly aid the drafting function and many provide some aid to selected design activities. For the development of mechanical systems, much more can be done. Future systems will aid the interactive engineering process of design, analysis, control, documentation, and manufacturing engineering. Computer based systems which address this broader spectrum of engineering activities are referred to as `Computer Aided Engineering,' or `CAE,' systems. CAE systems will use volumetric techniques to create and evaluate the individual components of a machine design in conjunction with data base management schemas to support the interrelationships of the components of machines. This paper focuses on computer assistance to the engineering of mechanical systems
keywords	mechanical engineering, CAE, solid modeling, objects
series	CADline
last changed	2003/06/02 13:58

_id	0189
authors	Brodlie, K.W. (editor)
year	1980
title	Mathematical Methods in Computer Graphics and Design
source	xi, 147 p. : ill. New York: Academic Press, 1980. includes subject index
summary	Based on the proceeding of the conference on mathematical methods in computer graphics and design, organized by the Institute of Mathematics and Its Applications and held at the university of Leicester on september 28th, 1978
keywords	algorithms, geometric modeling, techniques, computer graphics, mathematics
series	CADline
last changed	2003/06/02 13:58

_id	e952
authors	Carrara, Gianfranco and Paoluzzi, Alberto
year	1980
title	A Systems Approach to Building Program Planning
source	computer Aided Building Design Laboratory Research Report. 80 p. : ill. Rome, Italy: December, 1980. CABD LAB RR. 80-02. includes bibliography
summary	In this paper problems of design performance and of building program planning are considered from the view point of the general system theory. After having formalized the concept of requirement, performance and performance specification, it is shown that a set of building objects (spaces and constructive elements) foreseeable within a program is a semilattice, and that therefore the ordering of constructive elements and spaces corresponds to an ordering of relations among feasible 'behaviors.' A set of feasible behaviors is then presented as an abstract system, eventually discussing some assumptions on which to base an input-state-output representation of it
keywords	theory, methods, problem solving, architecture, design, knowledge
series	CADline
last changed	2003/06/02 13:58

_id	2ddb
authors	Davies, R.S.
year	1980
title	A Review of Computer Techniques for Representation of Geometry
source	1980? pp. 213-225 : ill. includes bibliography
summary	The primary role of the computer in the design process is to provide a means of recording the design, and subsequently of extracting information from the record. The choice of technique for recording geometry depends on the characteristics of the component and the nature of the information subsequently required about it. This paper reviews the principal techniques currently in use with particular emphasis on these two aspects
keywords	CAD, curves, representation, geometric modeling, techniques
series	CADline
last changed	2003/06/02 13:58

_id	ddss2004_ra-33
id	ddss2004_ra-33
authors	Diappi, L., P. Bolchim, and M. Buscema
year	2004
title	Improved Understanding of Urban Sprawl Using Neural Networks
source	Van Leeuwen, J.P. and H.J.P. Timmermans (eds.) Recent Advances in Design & Decision Support Systems in Architecture and Urban Planning, Dordrecht: Kluwer Academic Publishers, ISBN: 14020-2408-8, p. 33-49
summary	It is widely accepted that the spatial pattern of settlements is a crucial factor affecting quality of life and environmental sustainability, but few recent studies have attempted to examine the phenomenon of sprawl by modelling the process rather than adopting a descriptive approach. The issue was partly addressed by models of land use and transportation which were mainly developed in the UK and US in the 1970s and 1980s, but the major advances were made in the area of modelling transportation, while very little was achieved in the area of spatial and temporal land use. Models of land use and transportation are well-established tools, based on explicit, exogenouslyformulated rules within a theoretical framework. The new approaches of artificial intelligence, and in particular, systems involving parallel processing, (Neural Networks, Cellular Automata and Multi-Agent Systems) defined by the expression “Neurocomputing”, allow problems to be approached in the reverse, bottom-up, direction by discovering rules, relationships and scenarios from a database. In this article we examine the hypothesis that territorial micro-transformations occur according to a local logic, i.e. according to use, accessibility, the presence of services and conditions of centrality, periphericity or isolation of each territorial “cell” relative to its surroundings. The prediction capabilities of different architectures of supervised Neural networks are implemented to the south Metropolitan area of Milan at two different temporal thresholds and discussed. Starting from data on land use in 1980 and 1994 and by subdividing the area into square cells on an orthogonal grid, the model produces a spatial and functional map of urbanisation in 2008. An implementation of the SOM (Self Organizing Map) processing to the Data Base allows the typologies of transformation to be identified, i.e. the classes of area which are transformed in the same way and which give rise to territorial morphologies; this is an interesting by-product of the approach.
keywords	Neural Networks, Self-Organizing Maps, Land-Use Dynamics, Supervised Networks
series	DDSS
last changed	2004/07/03 22:13

_id	acadia07_164
id	acadia07_164
authors	Diniz, Nancy; Turner, Alasdair
year	2007
title	Towards a Living Architecture
source	Expanding Bodies: Art • Cities• Environment [Proceedings of the 27th Annual Conference of the Association for Computer Aided Design in Architecture / ISBN 978-0-9780978-6-8] Halifax (Nova Scotia) 1-7 October 2007, 164-173
doi	https://doi.org/10.52842/conf.acadia.2007.164
summary	Interaction is the latest currency in architecture, as responsive components are now reacting to the inhabitant of the space. These components are designed and installed by the architect with a view to the phenomenology of space, where the experience of the environment is previewed and pre-constructed before it is translated into the conception of the space. However, this traditional approach to new technology leaves no scope for the architecture to be alive in and of itself, and thus the installed piece quickly becomes just that—an installation: isolated and uncontained by its environment. In this paper, we argue that a way to approach a responsive architecture is to design for a piece that is truly living, and in order to propose a living architecture first we need to understand what the architecture of a living system is. This paper suggests a conceptual framework based on the theory of Autopoiesis in order to create a “self-producing” system through an experiment entitled, “The Life of a Wall” (Maturana and Varela 1980). The wall has a responsive membrane controlled by a genetic algorithm that reconfigures its behaviour and learns to adapt itself continually to the evolutionary properties of the environment, thus becoming a situated, living piece.
series	ACADIA
email
last changed	2022/06/07 07:55

_id	d22c
authors	Eastman, C.M.
year	1980
title	System Facilities for CAD Databases
source	17th Design Automation Conference Proceedings
summary	In this paper, an attempt is made to lay out the special needs of design databases, as compared to the facilities provided in conventional database systems now commercially available. The paper starts from a point of commonality and focusses on the limitations and shortcomings commonly found in current database systems. It is impossible and unwise to make universal statements about DBMS capabilities. Instead, the goal is to identify those special features that, by their capability, provide distinctions beyond the general notions of speed and ratio of logical size to physical size.
series	journal paper
email
last changed	2003/05/15 21:22

_id	076e
authors	Ennis, G. and Lindsay, M.
year	1999
title	VRML Possibilities: The evolution of the Glasgow Model
source	Proceedings of International Conference on Virtual Systems and MultiMedia. University of Abertay. Dundee
summary	During the 1980's, ABACUS, a research unit at the University of Strathclyde developed an interest in the ability to model and manipulate large geometrical databases of urban topography. Initially, this interest lay solely in the ability to source, capture and store the relevant data. However, once constructed, these models proved genuinely useful to a wide range of users and there was soon a demand for more functionality relating to the manipulation not just of the graphics, but also the range of urban attributes. Although a number of improvements were implemented there were drawbacks to the wide adoption of the software produced. The problems were almost all due to deficiencies in the then current hardware and software system available to the professions, and although this strand of research continued to be pursued, most of the development had to be focused on research applications and deployment. However, the recent advent of the Virtual Reality Modelling Language (VRML) standards have rekindled interest in this field since this language enables many of the issues that have proved problematic in the past to be addressed and solved. The potential now exists to provide wide access to large scale urban models. This paper focuses on the application of VRML as applied to the 'Glasgow Model'.
series	other
email
last changed	2003/04/23 15:50

_id	6a59
authors	Franklin, Randolph
year	1980
title	A Linear Time Exact Hidden Surface Algorithm
source	SIGGRAPH '80 Conference Proceedings. July, 1980. vol. 14 ; no. 3: pp. 117-133 : ill. includes bibliography
summary	This Paper presents a new hidden surface algorithm. Its output is the set of the visible pieces of edges and faces, and is as accurate as the arithmetic precision of the computer. Thus calculating the hidden surfaces for a higher resolution device takes no more time. If the faces are independently and identically distributed, then the execution time is linear in the number of faces. In particular, the execution time does not increase with the depth complexity. This algorithm overlays a grid on the screen whose fineness depends on the number and size of the faces. Edges and faces are sorted into grid cells. Only objects in the same cell can intersect or hide each other. Also, if a face completely covers a cell then nothing behind it in the cell is relevant. Three programs have tested this algorithm. The first verified the variable grid concept on 50,000 intersecting edges. The second verified the linear time, fast speed, and irrelevance of depth complexity for hidden lines on 10,000 spheres. This also tested depth complexities up to 30, and showed that perspective scenes with the farther objects smaller are even faster to calculate. The third verified this for hidden surfaces on 3,000 squares
keywords	hidden surfaces, algorithms, hidden lines, variables, grids, computer graphics, programming
series	CADline
last changed	2003/06/02 13:58

_id	c46e
authors	Fuchs, H., Kedem, Z.M. and Naylor, B.F.
year	1980
title	On Visible Surface Generation by a Priori Tree Structures
source	SIGGRAPH '80 Conference Proceedings. July, 1980. vol. 14 ; no. 3: pp. 124-133 : ill. includes bibliography
summary	This paper describes a new algorithm for solving the hidden surface (or line) problem, to more rapidly generate realistic images of 3-D scenes composed of polygons, and presents the development of theoretical foundations in the area as well as additional related algorithms. As in many applications the environment to be displayed consists of polygons many of whose relative geometric relations are static. It is attempted to capitalize on this by preprocessing the environment's database so as to decrease the run-time computations required to generate a scene. This preprocessing is based on generating a 'binary space partitioning' tree whose inorder traversal of visibility priority at run-time will produce a linear order, dependent upon the viewing position, on (parts of) the polygons, which can then be used to easily solve the hidden surface problem. In the application where the entire environment is static with only the viewing-position changing, as is common in simulation, the results presented will be sufficient to solve completely the hidden surface problem
keywords	hidden lines, hidden surfaces, algorithms, computer graphics, polygons
series	CADline
last changed	2003/06/02 14:42

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