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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	678e
authors	Aish, Robert
year	1986
title	Three-dimensional Input and Visualization
source	Computer-Aided Architectural Design Futures [CAAD Futures Conference Proceedings / ISBN 0-408-05300-3] Delft (The Netherlands), 18-19 September 1985, pp. 68-84
summary	The aim of this chapter is to investigate techniques by which man-computer interaction could be improved, specifically in the context of architectural applications of CAD. In this application the object being designed is often an assembly of defined components. Even if the building is not actually fabricated from such components, it is usually conceptualized in these terms. In a conventional graphics- based CAD system these components are usually represented by graphical icons which are displayed on the graphics screen and arranged by the user. The system described here consists of three- dimensional modelling elements which the user physically assembles to form his design. Unlike conventional architectural models which are static (i.e. cannot be changed by the users) and passive (i.e. cannot be read by a CAD system), this model is both 'user generated' and 'machine readable'. The user can create, edit and view the model by simple, natural modelling activities and without the need to learn complex operating commands often associated with CAD systems. In particular, the user can view the model, altering his viewpoint and focus of attention in a completely natural way. Conventional computer graphics within an associated CAD system are used to represent the detailed geometry which the different three-dimensional icons may represent. In addition, computer graphics are also used to present the output of the performance attributes of the objects being modelled. In the architectural application described in this chapter an energy- balance evaluation is displayed for a building designed using the modelling device. While this system is not intended to offer a completely free-form input facility it can be considered to be a specialist man-machine interface of particular relevance to architects or engineers.
series	CAAD Futures
email
last changed	2003/11/21 15:15

_id	4ed0
authors	Bartels, R.H., Beatty, J.C. and Barsky, B.A.
year	1986
title	An Introduction to Splines for Use in Computer Graphics and Geometric Modeling
source	xiv, 476 p. : ill. (some col.) Los Altos, California: Morgan Kaufmann Pub. Inc., 1986. Forewords by Pierre Bezier and Robin A. Forrest. Includes bibliography: p. 455-465 and index
summary	Discusses the use of splines from the point of view of the computer scientist concentrating on parametric spline curves and parametric,tensor-product spline surfaces
keywords	splines, theory, computer graphics, computational geometry
series	CADline
last changed	2003/06/02 14:42

_id	09b3
authors	Bier, Eric A. and Sloan, Kenneth R. Jr.
year	1986
title	Two-Part Texture Mappings
source	IEEE Computer Graphics and Applications September, 1986. pp. 40-53 : col. ill. includes bibliography.
summary	Most published techniques for mapping two-dimensional texture patterns onto three-dimensional curved surfaces assume that either the texture pattern has been predistorted to compensate for the distortion of the mapping or the curved surfaces are represented parametrically. The authors address the problem of mapping undistorted planar textures onto arbitrarily represented surfaces. Their mapping technique is done in two parts. First the texture pattern is embedded in 3- space on an intermediate surface. Then the pattern is projected onto the target surface in a way that depends only on the geometry of the target object (not on its parametrization). Both steps have relatively low distortion, so the original texture need not be predistorted. The authors also discuss interactive techniques that make two-part mapping practical
keywords	texture mapping, curved surfaces, computer graphics, rendering
series	CADline
last changed	2003/06/02 10:24

_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	4418
authors	Franklin, Randolph, Wu, Peter, Y. F. and Samaddar, Sumitro (et al)
year	1986
title	Prolog and Geometry Projects
source	IEEE Computer Graphics and Applications. November, 1986. vol. 6: pp. 46-55 : ill. includes bibliography
summary	Prolog is a useful tool for geometry and graphics implementations because its primitives, such as unification, match the requirements of many geometric algorithms. During the last two years, programs have been implemented to solve several problems in Prolog, including a subset of the Graphical Kernel System, convex-hull calculation, planar graph traversal, recognition of groupings of objects, Boolean combinations of polygons using multiple precision rational numbers, and cartographic map overlay. Certain paradigms or standard forms of geometric programming in Prolog are becoming evident. They include applying a function to every element of a set, executing a procedure so long as a certain geometric pattern exists, and using unification to propagate a transitive function. This article describes the experiences, including paradigms of programming that seem useful, and finally lists those considered as the advantages and disadvantages of Prolog
keywords	geometric modeling, computer graphics, PROLOG, programming
series	CADline
last changed	2003/06/02 13:58

_id	a241
authors	Freund, Dwight D.
year	1986
title	A Note : An Interactive Procedure for Constructing Line and Circle Tangencies
source	IEEE Computer Graphics and Applications. April, 1986. vol. 6: pp. 59-63 : ill. includes bibliography
summary	This note describes a procedure that enables a designer or draftsperson with limited mathematical training to discover interactively the construction of a wide variety of tangency and intersection problems. Requiring very little code to implement, it supplements the standard tangency constructions available on commercial turnkey computer-aided-design systems with a flexibility unavailable even through the inclusion of the numerous special-purpose algorithms available in the literature
keywords	drawings, circles, computational geometry, user interface
series	CADline
last changed	2003/06/02 10:24

_id	0354
authors	Goodman, Gary and Reddy, Raj D.
year	1978
title	Alternative Control Structures for Speech Understanding Systems
source	1978 ? [13] p. : ill. includes bibliography Control structures are an essential part of any speech recognition system. They are the devices by which passive knowledge about the task and language is transformed into active and effective processes. In the chapter, three areas of control structures are defined and discussed: knowledge source interaction, knowledge source activation, and knowledge source focusing. Discussion relates the concepts presented to systems developed during the five-year ARPA speech understanding project. speech recognition / systems / control / structures / AI. 64. Goodman, Tim and Keith Unsworth. 'Manipulating Shape and Producing Geometric Continuity in B-spline Curves.' IEEE Computer Graphics and Applications. February, 1986. vol. 6: pp. 50-56 : ill. includes bibliography.
summary	This article examines some of the desirable features of B- splines that make them particularly suitable for computer- aided design. First, a theoretical analysis is presented regarding the effects upon the shape of a design curve when the bias and tension parameters are allowed to vary in certain ways. Second, the concept of geometric continuity is discussed, and conditions are derived upon the control vertices to ensure that the design curve has second-order geometric continuity. Illustrations of B-spline curves are presented to support the theoretical conclusions
keywords	computational geometry, B-splines, curves, CAD
series	CADline
last changed	2003/06/02 13:58

_id	4e59
authors	Koparkar, P. A. and Mudur, S.P.
year	1986
title	Generation of Continuous Smooth Curves Resulting from Operations on Parametric Surface Patches
source	Computer Aided Design. May, 1986. pp. 193-206 : ill. includes bibliography
summary	In recent years a number of techniques based on the subdivision principle have been suggested for detecting the curves resulting from the intersection of two parametrically defined surface patches. Silhouette curves of surfaces can also be detected using analogous techniques. Usually the output is a set of pixels or line segments which form the complete curve, though not necessarily in an ordered manner. This paper presents data structures for maintaining the result of subdivision, and algorithms for tracing the curves in a continuous fashion. Using a few iterations of the Newton-Raphson technique the curve points may be refined to any required precision. For each point on the curve the nonlinear equations are chosen by looking at the local topological nature of the curve so as to guarantee convergence of the Newton-Raphson technique in one or two iterations
keywords	curved surfaces, parametrization, curves, intersection, relaxation, geometric modeling, computational geometry
series	CADline
last changed	2003/06/02 14:41

_id	8816
authors	Penn, Michael A. and Patterson, Richard R.
year	1986
title	Projective Geometry and its Application to Computer Graphics
source	xi, 403 p. Englewood Cliffs, New Jersey: Prentice Hall, 1986. includes bibliography: p. 394-395
summary	The goal of the book is to support the design of solutions to computer graphic problems through an understanding of the underlying elements of projective geometry. Some of the topics discussed are: How to view the structure of two and three dimensional graphic libraries, how to create two dimensional perspective and parallel images of a three dimensional object, how to draw the graph of a function of two real variables, and more
keywords	computer graphics, projective geometry
series	CADline
last changed	2003/06/02 13:58

_id	4577
authors	Piegl, L.
year	1986
title	Representation of Rational Bezier Curves and Surfaces by Recursive Algorithms
source	Computer Aided Design Butterworth & Co. (publishers) Ltd., September, 1986. vol. 18: pp. 361-366 : ill.
summary	includes a short bibliography. Recursive algorithms for the computation and subdivision of rational Bezier curves and surfaces are presented. The development uses the relationship between the R4 geometry and the rational scheme
keywords	curves, curved surfaces, recursion, Bezier, representation
series	CADline
last changed	2003/06/02 13:58

_id	6728
authors	Rossignac, Jaroslaw R. and Requicha, Aristides A. G.
year	1986
title	Depth- Buffering Display Techniques for Constructive Solid Geometry
source	IEEE Computer Graphics and Applications. September, 1986. vol. 6: pp. 29-39 : ill. some col. includes bibliography
summary	Solid modelers based on constructive solid geometry (CSG) typically generate shaded displays directly from CSG by using ray-casting techniques, which do not require information on the faces, edges, and vertices that bound a solid. This article describes an alternative - a simple new algorithm based on a depth-buffering or z-buffering approach. The z- buffer display algorithm operates directly on CSG, does not require explicit boundary data, and is easier to implement than ray casting. Ray-casting and z-buffering algorithms have comparable performances, but z-buffering is often faster for objects with complex surfaces, because it avoids expensive curve/surface intersection calculations. Because of their simplicity, depth-buffering algorithms for CSG are well- suited to hardware implementations, and may lead to machines simpler than those now being built for ray casting
keywords	geometric modeling, CSG, display, computer graphics
series	CADline
last changed	2003/06/02 13:58

_id	28d8
authors	Sarnak, Neil and Tarjan, Robert E.
year	1986
title	Planar Point Location Using Persistent Search Trees
source	Communications of the ACM July, 1986. vol. 29: pp. 669-679 : ill. includes bibliography.
summary	A classical problem in computational geometry is the planar point location problem. This problem calls for preprocessing a polygonal subdivision of the plane defined by n line segments so that, given a sequence of points, the polygon containing each point can be determined quickly on-line. Several ways of solving this problem in O(log n) query time and O(n) space are known, but they are all rather complicated. The authors propose a simple O(log n) query-time, O(n) space solution, using persistent search trees. A persistent search tree differs from an ordinary search tree in that after an insertion or deletion, the old version of the tree can stillÔ h)000*°° ÔŒ be accessed. A persistent form of binary search tree that supports insertions and deletions in the present and queries in the past is developed. The time per query or update is O(log m), where m is the total number of updates, and the space needed is O(1) per update. The planar point location algorithm is an immediate application of this data structure. The structure also provides an alternative to Chazelle's 'hive graph' structure, which has a variety of applications in geometric retrieval
keywords	search, data structures, algorithms, point inclusion, computational geometry
series	CADline
last changed	2003/06/02 13:58

_id	c92d
authors	Sederberg, Thomas W. and Goldman, Ronald N.
year	1986
title	Algebraic Geometry for Computer-Aided Geometric Design
source	IEEE Computer Graphics and Applications. June, 1986. vol. 6: pp. 52-59
summary	An object description associating a tolerance with each of its topological features (vertices, edges, and faces) is introduced. The use of tolerances leads to a definition of topological consistency that is readily applied to boundary representations. The implications of using tolerances to aid in making consistent topological determinations from imprecise geometric data are explored and applied to the calculations of a polyhedral solid modeler
keywords	Algorithms; Curves; Computational Geometry; Mathematics; Education; Intersection
series	CADline
last changed	2003/06/02 10:24

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