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	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	66eb
authors	Grayer, Alan R.
year	1980
title	Alternative Approaches in Geometric Modelling
source	Computer Aided Design. July, 1980. vol. 12: pp. 189-192 : ill. includes bibliography
summary	As systems for computer-aided design and production of mechanical parts have developed there has arisen a need for techniques for the comprehensive description of the desired part, including its three-dimensional shape. The creation and manipulation of shapes is generally known as Geometric Modelling, but some misconceptions have arisen as to the true meaning and import of the term. The paper argues for a broad, flexible approach to the subject, allowing the use of many techniques suited to particular applications, unifying them through common data structures
keywords	data structures, geometric modeling, solids
series	CADline
last changed	2003/06/02 10:24

_id	ga9809
id	ga9809
authors	Kälviäinen, Mirja
year	1998
title	The ideological basis of generative expression in design
source	International Conference on Generative Art
summary	This paper will discuss issues concerning the design ideology supporting the use and development of generative design. This design ideology is based on the unique qualities of craft production and on the forms or ideas from nature or the natural characteristics of materials. The main ideology presented here is the ideology of the 1980´s art craft production in Finland. It is connected with the general Finnish design ideology and with the design ideology of other western countries. The ideology for these professions is based on the common background of design principles stated in 19th century England. The early principles developed through the Arts and Crafts tradition which had a great impact on design thinking in Europe and in the United States. The strong continuity of this design ideology from 19th century England to the present computerized age can be detected. The application of these design principles through different eras shows the difference in the interpretations and in the permission of natural decorative forms. The ideology of the 1980ïs art craft in Finland supports the ideas and fulfilment of generative design in many ways. The reasons often given as the basis for making generative design with computers are in very many respects the same as the ideology for art craft. In Finland there is a strong connection between art craft and design ideology. The characteristics of craft have often been seen as the basis for industrial design skills. The main themes in the ideology of the 1980´s art craft in Finland can be compared to the ideas of generative design. The main issues in which the generative approach reflects a distinctive ideological thinking are: Way of Life: The work is the communication of the maker´s inner ideas. The concrete relationship with the environment, personality, uniqueness, communication, visionary qualities, development and growth of the maker are important. The experiments serve as a media for learning. Taste and Aesthetic Education: The real love affair is created by the non living object with the help of memories and thought. At their best objects create the basis in their stability and communication for durable human relationships. People have warm relationships especially with handmade products in which they can detect unique qualities and the feeling that the product has been made solely for them. Counter-culture: The aim of the work is to produce alternatives for technoburocracy and mechanical production and to bring subjective and unique experiences into the customerïs monotonious life. This ideology rejects the usual standardized mass production of our times. Mythical character: There is a metamorphosis in the birth of the product. In many ways the design process is about birth and growth. The creative process is a development story of the maker. The complexity of communication is the expression of the moments that have been lived. If you can sense the process of making in the product it makes it more real and nearer to life. Each piece of wood has its own beauty. Before you can work with it you must find the deep soul of its quality. The distinctive traits of the material, technique and the object are an essential part of the metamorphosis which brings the product into life. The form is not only for formïs sake but for other purposes, too. You cannot find loose forms in nature. Products have their beginnings in the material and are a part of the nature. This art craft ideology that supports the ideas of generative design can be applied either to the hand made crafts production or to the production exploiting new technology. The unique characteristics of craft and the expression of the material based development are a way to broaden the expression and forms of industrial products. However, for a crafts person it is not meaningful to fill the world with objects. In generative, computer based production this is possible. But maybe the production of unique pieces is still slower and makes the industrial production in that sense more ecological. People will be more attached to personal and unique objects, and thus the life cycle of the objects produced will be longer.
series	other
email
more	http://www.generativeart.com/
last changed	2003/08/07 17:25

_id	08ba
authors	Requicha, Aristides A.G.
year	1980
title	Representations for Rigid Solids : Theory, Methods, and Systems
source	Computing Surveys December, 1980. vol. 12: pp. 437-464 : ill. includes bibliography.
summary	Computer-based systems for modeling the geometry of rigid solid objects are becoming increasingly important in mechanical and civil engineering, architecture, computer graphics, computer vision, and other fields that deal with spatial phenomena. At the heart of such systems are symbol structures (representations) designating 'abstract solids' (subsets of Euclidean space) that model physical solids. Representations are the sources of data for procedures which compute useful properties of objects. The variety and uses of systems embodying representations of solids are growing rapidly, but so are the difficulties in assessing current designs, specifying the characteristics that future systems should exhibit, and designing systems to meet such specifications. This paper resolves many of these difficulties by providing a coherent view, based on sound theoretical principles, of what is presently known about the representation of solids. The paper is divided into three parts. The first introduces a simple mathematical framework for characterizing certain important aspects of representations, for example, their semantic (geometric) integrity. The second part uses the framework to describe and compare all of the major known schemes for representing solids. The third part briefly surveys extant geometric modeling systems and then applies the concepts developed in the paper to the high-level design of a multiple- representation geometric modeling system which exhibits a level of reliability and versatility superior to that of systems currently used in industrial computer-aided design and manufacturing
keywords	CAD, CAM, computational geometry, geometric modeling, representation,CSG, B-rep
series	CADline
last changed	2003/06/02 13:58

_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	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	0105
authors	Bossan, Mario and Ronchi, Alfredo M.
year	1989
title	Presentazione Esperienza Didattica del Dipartimento di Ingegneria dei Sistemi Edilizi e Territoriali - Politecnico di Milano
doi	https://doi.org/10.52842/conf.ecaade.1989.x.x4i
source	CAAD: Education - Research and Practice [eCAADe Conference Proceedings / ISBN 87-982875-2-4] Aarhus (Denmark) 21-23 September 1989, pp. 9.8.1-9.8.19
summary	Didactic and research experience developed at the "Dipartimento di Ingegneria dei Sistemi Edilizi e Territoriali del Politecnico di Milano" in the environment of Computer Aided Architectural Design (CAAD). From the early part of the 1980's, using initially at an experimental level the resources available at the departmental centre of calculation various applications of CAD techniques in the building sector have been effected at DISET (Dipartimento di Ingegneria del Politecnico di Milano). During 1983, after a three year period of experimenting with these systems, it was decided to organise and activate a small computer aided design centre, within the department, the use of which was reserved for dissertation and research students.
series	eCAADe
email
last changed	2022/06/07 07:50

_id	8593
authors	Braid, I.C.
year	1980
title	Superficial Blends in Geometric Modelling
source	12 p. : ill. February, 1980. Document No. 105. includes bibliography
summary	In engineering practice, many blended surfaces are both indicated and manufactured by rounding off a sharp edge. The authors term them `superficial' blends in contrast to `designed' blends for which existing surface techniques are appropriate. The provision of superficial blends in a geometric modeling system is explained, and a method is given for drawing objects containing blended edges
keywords	geometric modeling, CAD, representation, solids
series	CADline
last changed	2003/06/02 13:58

_id	e2a9
authors	Carpenter, Loren
year	1980
title	Computer Rendering of Fractal Curves and Surfaces
source	Computer Graphics: SIGGRAPH Proceedings, Vol 14, no 3 (supplement), July 1980, pp 9-
summary	Fractals are a class of highly irregular shapes that have myriad counterparts in the real world, such as islands, river networks, turbulence, and snowflakes. Classic fractals include Brownian paths, Cantor sets, and plane-filling curves. Nearly all fractal sets are of fractional dimension and all are nowhere differentiable. Previously published procedures for calculating fractal curves employ shear displacement processes, modified Markov processes, and inverse Fourier transforms. They are either very expensive or very complex and do not easily generalize to surfaces. This paper presents a family of simple methods for generating and displaying a wide class of fractal curves and surfaces. In so doing, it introduces the concept of statistical subdivision in which a geometric entity is split into smaller entities while preserving certain statistical properties.
series	journal paper
last changed	2003/04/23 15:14

_id	a587
authors	Cohen, Elaine, Lyche, Tom and Riesenfeld, Richard F.
year	1980
title	Discrete B-Splines and Subdivision Techniques in Computer-Aided Geometric Design and Computer Graphics
source	computer Graphics and Image Processing. October, 1980. vol. 14: pp. 87- 111 : ill. includes bibliography
summary	The relevant theory of discrete B-splines with associated new algorithms is extended to provide a framework for understanding and implementing general subdivision schemes for nonuniform B-splines. The new derived polygon corresponding to an arbitrary refinement of the knot vector for an existing B-spline curve, including multiplicities, is shown to be formed by successive evaluations of the discrete B-spline defined by the original vertices, the original knot vector, and the refined knot vector. Existing subdivision algorithms can be seen as proper special cases. General subdivision has widespread applications in computer-aided geometric design, computer graphics, and numerical analysis. The new algorithms resulting from the new theory lead to a unification of the display model, the analysis model, and other needed models into a single geometric model from which other necessary models are easily derived. New sample algorithms for interference calculation, contouring, surface rendering, and other important calculations are presented
keywords	computational geometry, theory, algorithms, computer graphics, B-splines, curved surfaces
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	acadia07_164
id	acadia07_164
authors	Diniz, Nancy; Turner, Alasdair
year	2007
title	Towards a Living Architecture
doi	https://doi.org/10.52842/conf.acadia.2007.164
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
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	659f
authors	Earl, C.F.
year	1981
title	Enumerating Architectural Arrangements : Comment on a Recent Paper by Baybars and Eastman
source	Environment and Planning B. 1981. vol. 8: pp. 115-118 : ill. includes bibliography. -- See Baybars, I. and Eastman, Charles M. 'Enumerating Architectural Arrangements by Generating Their Underlying Graphs' (Environmental and Planning B, 1980, vol.7, pp. 289-310)
summary	Comments and discussion on the method proposed for generating the graphs for enumerating architectural arrangements by Baybars and Eastman (1980)
keywords	enumeration, architecture, floor plans, graphs
series	CADline
last changed	2003/05/17 10:15

_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	c444
authors	Forrest, Robin A.
year	1980
title	The Twisted Cubic Curve : A Computer-Aided Geometric Design Approach
source	Computer Aided Design. July, 1980. vol. 12: pp. 165-172 : ill. includes bibliography
summary	The twisted cubic curve has the attraction of combining both commonly used curve definitions, the conic section and the parametric cubic, in a single form. A definition of the twisted cubic is developed in terms of geometric `handles' convenient for CAD and independent of parametrization, analogous to a well-known definition of conics. Conditions for the occurrence of asymptotes are investigated and shown to be considerably more complex than those for conics. Several more controllable subsets of the general curve are described. The paper concludes that use of the full generality of the twisted cubic is in most cases unjustified
keywords	computational geometry, curves, CAD, parametrization
series	CADline
last changed	2003/06/02 13:58

_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

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