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

PDF papers
References

Hits 1 to 20 of 145

_id c341
authors Cohen, Michael F. and Greenberg, Donald P.
year 1985
title The Hemi-Cube: A Radiosity Solution for Complex Environments
source SIGGRAPH '85 conference proceedings. July, 1985. vol. 19 ; no. 3: pp. 31-39 : ill. (some col.). includes bibliography
summary This paper presents a comprehensive method to calculate object to object diffuse reflections within complex environments containing hidden surfaces and shadows. In essence, each object in the environment is treated as a secondary light source. The method provides an accurate representation of the 'diffuse' and 'ambient' terms found in typical image synthesis algorithms. The phenomena of 'color bleeding' from one surface to another, shading within shadow envelopes, and penumbras along shadow boundaries are accurately reproduced. Additional advantages result because computations are independent of viewer position. This allows the efficient rendering of multiple views of the same scene for dynamic sequences. Light sources can be modulated and object reflectivities can be changed, with minimal extra computation. The procedures extend the radiosity method beyond the bounds previously imposed
keywords hidden surfaces, shadowing, computer graphics, geometric modeling, radiosity
series CADline
last changed 2003/06/02 13:58

_id c547
authors Fenves, Stephen J. and Rasdorf, William J.
year 1985
title Treatment of Engineering Design Constraints in a Relational Database
source Engineering with Computers. Springer-Verlag, Spring, 1985. vol. 1: pp. 27-37. includes bibliography
summary A major aspect of engineering design is the formulation, application, evaluation, and satisfaction of design constraints. The ability to represent and process a wide variety of such constraints is a necessary ingredient of an engineering design database. This is especially true in databases integrating several design processes, where the database management system must serve as an active design agent performing many of the consistency and integrity checks that are currently done manually. This paper presents a mechanism for representing and processing engineering design constraints. The mechanism can be used for checking that constraints are satisfied as well as for deriving attribute values that satisfy the applicable constraints. Furthermore, the mechanism provides flexibility in sequencing the enforcement of constraints by allowing new constraints to be applied to a preexisting state of the database as well as to all subsequent operations on the database. In both these respects, the mechanism proposed appears to have applications beyond engineering design. The mechanism presented handles a broad class of single-relation, single-tuple constraints typical in engineering design applications. Instead of relying on normalization where possible, to remove functional dependencies, the mechanism incorporates new attributes that represent the status (satisfied or violated) of each constraint, thereby increasing the functional dependence of the relation. Consequently, passive constraint checking can be readily extended to active assignment of attribute values that automatically satisfy constraints. A prototype system implementing many of the components presented has been programmed in Pascal. In addition, portions of the system were implemented using the Relational Information Management (RIM) system, a commercially available DBMS
keywords civil engineering, design, knowledge, relational database, CAE, constraints management
series CADline
last changed 2003/06/02 13:58

_id 4494
authors Maher, Mary Lou
year 1985
title Hi-Rise and Beyond : Directions for Expert Systems in Design
source Computer Aided Design. November, 1985. vol. 17: pp. 420-427 : ill. includes bibliography
summary This paper commences with a brief introduction to expert systems and then describes the Hi-Rise expert system for structural design in terms of scope, problem solving strategy, knowledge representation and implementation. It then discusses the potential for developing an expert system capable of innovative design and describes the possibility of developing a generic expert system framework appropriate for any structural design problem
keywords expert systems, civil engineering, structures, knowledge, representation, synthesis
series CADline
email
last changed 2003/05/17 10:19

_id ce52
authors Abram, Greg, Weslover, Lee and Whitted, Turner
year 1985
title Efficient Alias-Free Rendering using Bit-masks and Look-up Tables
source SIGGRAPH '85 Conference Proceedings. July, 1985. vol. 19 ; no. 3: pp. 53-59 : ill. (some col.). includes bibliography
summary The authors demonstrate methods of rendering alias-free synthetic images using a precomputed convolution integral. The method is based on the observation that a visible polygon fragment's contribution to an image is solely a function of its position and shape, and that within a reasonable level of accuracy, a limited number of shapes represent the majority of cases encountered in images commonly rendered. The basic technique has been applied to several different rendering algorithms. A version of the newly non-uniform sampling technique implemented in the same program but with different tables values was introduced
keywords algorithms, computer graphics, anti-aliasing
series CADline
last changed 2003/06/02 13:58

_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 6de2
authors Burnett, J. Jeffrey
year 1985
title A Prototype Voice Operated Computer Aided Design Workstation Intended for High Productivity Commercial & Educational Use
doi https://doi.org/10.52842/conf.acadia.1985.083
source ACADIA Workshop ‘85 [ACADIA Conference Proceedings] Tempe (Arizona / USA) 2-3 November 1985, pp. 83-95
summary The recent availability of easy to use, tow cost voice recognition input devices combined with increasingly sophisticated mini and micro-computer based Computer Aided Design (CAD) systems offer numerous possibilities for quadriplegics to enter (or re-enter) the job market as draft-persons and design professionals. Serious productivity potential needs much more study, however, preliminary benchmarks indicate that it would be reasonable to expect ratios of .9 to 1.4 over manual drafting using the configuration described.
series ACADIA
last changed 2022/06/07 07:54

_id avocaad_2001_02
id avocaad_2001_02
authors Cheng-Yuan Lin, Yu-Tung Liu
year 2001
title A digital Procedure of Building Construction: A practical project
source AVOCAAD - ADDED VALUE OF COMPUTER AIDED ARCHITECTURAL DESIGN, Nys Koenraad, Provoost Tom, Verbeke Johan, Verleye Johan (Eds.), (2001) Hogeschool voor Wetenschap en Kunst - Departement Architectuur Sint-Lucas, Campus Brussel, ISBN 80-76101-05-1
summary In earlier times in which computers have not yet been developed well, there has been some researches regarding representation using conventional media (Gombrich, 1960; Arnheim, 1970). For ancient architects, the design process was described abstractly by text (Hewitt, 1985; Cable, 1983); the process evolved from unselfconscious to conscious ways (Alexander, 1964). Till the appearance of 2D drawings, these drawings could only express abstract visual thinking and visually conceptualized vocabulary (Goldschmidt, 1999). Then with the massive use of physical models in the Renaissance, the form and space of architecture was given better precision (Millon, 1994). Researches continued their attempts to identify the nature of different design tools (Eastman and Fereshe, 1994). Simon (1981) figured out that human increasingly relies on other specialists, computational agents, and materials referred to augment their cognitive abilities. This discourse was verified by recent research on conception of design and the expression using digital technologies (McCullough, 1996; Perez-Gomez and Pelletier, 1997). While other design tools did not change as much as representation (Panofsky, 1991; Koch, 1997), the involvement of computers in conventional architecture design arouses a new design thinking of digital architecture (Liu, 1996; Krawczyk, 1997; Murray, 1997; Wertheim, 1999). The notion of the link between ideas and media is emphasized throughout various fields, such as architectural education (Radford, 2000), Internet, and restoration of historical architecture (Potier et al., 2000). Information technology is also an important tool for civil engineering projects (Choi and Ibbs, 1989). Compared with conventional design media, computers avoid some errors in the process (Zaera, 1997). However, most of the application of computers to construction is restricted to simulations in building process (Halpin, 1990). It is worth studying how to employ computer technology meaningfully to bring significant changes to concept stage during the process of building construction (Madazo, 2000; Dave, 2000) and communication (Haymaker, 2000).In architectural design, concept design was achieved through drawings and models (Mitchell, 1997), while the working drawings and even shop drawings were brewed and communicated through drawings only. However, the most effective method of shaping building elements is to build models by computer (Madrazo, 1999). With the trend of 3D visualization (Johnson and Clayton, 1998) and the difference of designing between the physical environment and virtual environment (Maher et al. 2000), we intend to study the possibilities of using digital models, in addition to drawings, as a critical media in the conceptual stage of building construction process in the near future (just as the critical role that physical models played in early design process in the Renaissance). This research is combined with two practical building projects, following the progress of construction by using digital models and animations to simulate the structural layouts of the projects. We also tried to solve the complicated and even conflicting problems in the detail and piping design process through an easily accessible and precise interface. An attempt was made to delineate the hierarchy of the elements in a single structural and constructional system, and the corresponding relations among the systems. Since building construction is often complicated and even conflicting, precision needed to complete the projects can not be based merely on 2D drawings with some imagination. The purpose of this paper is to describe all the related elements according to precision and correctness, to discuss every possibility of different thinking in design of electric-mechanical engineering, to receive feedback from the construction projects in the real world, and to compare the digital models with conventional drawings.Through the application of this research, the subtle relations between the conventional drawings and digital models can be used in the area of building construction. Moreover, a theoretical model and standard process is proposed by using conventional drawings, digital models and physical buildings. By introducing the intervention of digital media in design process of working drawings and shop drawings, there is an opportune chance to use the digital media as a prominent design tool. This study extends the use of digital model and animation from design process to construction process. However, the entire construction process involves various details and exceptions, which are not discussed in this paper. These limitations should be explored in future studies.
series AVOCAAD
email
last changed 2005/09/09 10:48

_id ascaad2006_paper20
id ascaad2006_paper20
authors Chougui, Ali
year 2006
title The Digital Design Process: reflections on architectural design positions on complexity and CAAD
source Computing in Architecture / Re-Thinking the Discourse: The Second International Conference of the Arab Society for Computer Aided Architectural Design (ASCAAD 2006), 25-27 April 2006, Sharjah, United Arab Emirates
summary These instructions are intended to guide contributors to the Second Architecture is presently engaged in an impatient search for solutions to critical questions about the nature and the identity of the discipline, and digital technology is a key agent for prevailing innovations in architectural design. The problem of complexity underlies all design problems. With the advent of CAD however, Architect’s ability to truly represent complexity has increased considerably. Another source that provides information about dealing with complexity is architectural theory. As Rowe (1987) states, architectural theory constitutes “a corpus of principles that are agreed upon and therefore worthy of emulation”. Architectural theory often is a mixed reflection on the nature of architectural design, design processes, made in descriptive and prescriptive terms (see Kruft 1985). Complexity is obviously not a new issue in architectural theory. Since it is an inherent characteristic of design problems, it has been dealt with in many different ways throughout history. Contemporary architects incorporate the computer in their design process. They produce architecture that is generated by the use of particle systems, simulation software, animation software, but also the more standard modelling tools. The architects reflect on the impact of the computer in their theories, and display changes in style by using information modelling techniques that have become versatile enough to encompass the complexity of information in the architectural design process. In this way, architectural style and theory can provide directions to further develop CAD. Most notable is the acceptance of complexity as a given fact, not as a phenomenon to oppose in systems of organization, but as a structuring principle to begin with. No matter what information modelling paradigm is used, complex and huge amounts of information need to be processed by designers. A key aspect in the combination of CAD, complexity, and architectural design is the role of the design representation. The way the design is presented and perceived during the design process is instrumental to understanding the design task. More architects are trying to reformulate this working of the representation. The intention of this paper is to present and discuss the current state of the art in architectural design positions on complexity and CAAD, and to reflect in particular on the role of digital design representations in this discussion. We also try to investigate how complexity can be dealt with, by looking at architects, in particular their styles and theories. The way architects use digital media and graphic representations can be informative how units of information can be formed and used in the design process. A case study is a concrete architect’s design processes such as Peter Eisenman Rem Koolhaas, van Berkel, Lynn, and Franke gehry, who embrace complexity and make it a focus point in their design, Rather than viewing it as problematic issue, by using computer as an indispensable instrument in their approaches.
series ASCAAD
email
last changed 2007/04/08 19:47

_id 23bc
authors Demko, Stephen, Hodges, Laurie and Naylor, Bruce F.
year 1985
title Construction of Fractal Objects with Iterated Function Systems
source SIGGRAPH '85 Conference Proceedings. July, 1985. vol. 19 ; no. 3: pp. 271-278 : ill. col. includes bibliography
summary In computer graphics, geometric modeling of complex objects is a difficult process. An important class of complex objects arise from natural phenomena: trees, plants, clouds, mountains, etc. Researchers are investigating a variety of techniques for extending modeling capabilities to include these as well as other classes. One mathematical concept that appears to have significant potential for this is fractals. Much interest currently exists in the general scientific community in using fractals as a model of complex natural phenomena. However, only a few methods for generating fractal sets are known. We have been involved in the development of a new approach to computing fractals. Any set of linear maps (affine transformations) and an associated set of probabilities determines an Iterated Function System (IFS). Each IFS has a unique 'attractor' which is typically a fractal set (object). Specification of only a few maps can produce very complicated objects. Design of fractal objects is made relatively simple and intuitive by the discovery of an important mathematical property relating the fractal sets to the IFS. The method also provides the possibility of solving the inverse problem, given the geometry of an object, determine an IFS that will (approximately) generate that geometry. This paper presents the application of the theory of IFS to geometric modeling
keywords computer graphics, geometric modeling, fractals, visualization
series CADline
last changed 2003/06/02 13:58

_id c898
authors Gero, John S.
year 1986
title An Overview of Knowledge Engineering and its Relevance to CAAD
source Computer-Aided Architectural Design Futures [CAAD Futures Conference Proceedings / ISBN 0-408-05300-3] Delft (The Netherlands), 18-19 September 1985, pp. 107-119
summary Computer-aided architectural design (CAAD) has come to mean a number of often disparate activities. These can be placed into one of two categories: using the computer as a drafting and, to a lesser extent, modelling system; and using it as a design medium. The distinction between the two categories is often blurred. Using the computer as a drafting and modelling tool relies on computing notions concerned with representing objects and structures numerically and with ideas of computer programs as procedural algorithms. Similar notions underly the use of computers as a design medium. We shall return to these later. Clearly, all computer programs contain knowledge, whether methodological knowledge about processes or knowledge about structural relationships in models or databases. However, this knowledge is so intertwined with the procedural representation within the program that it can no longer be seen or found. Architecture is concerned with much more than numerical descriptions of buildings. It is concerned with concepts, ideas, judgement and experience. All these appear to be outside the realm of traditional computing. Yet architects discoursing use models of buildings largely unrelated to either numerical descriptions or procedural representations. They make use of knowledge - about objects, events and processes - and make nonprocedural (declarative) statements that can only be described symbolically. The limits of traditional computing are the limits of traditional computer-aided design systems, namely, that it is unable directly to represent and manipulate declarative, nonalgorithmic, knowledge or to perform symbolic reasoning. Developments in artificial intelligence have opened up ways of increasing the applicability of computers by acquiring and representing knowledge in computable forms. These approaches supplement rather than supplant existing uses of computers. They begin to allow the explicit representations of human knowledge. The remainder of this chapter provides a brief introduction to this field and describes, through applications, its relevance to computer- aided architectural design.
series CAAD Futures
email
last changed 2003/05/16 20:58

_id 0551
authors Haller, Fritz
year 1985
title The Design of Buildings Which Have Complex Mechanical Infrastructure Using Expert Systems
source 1985? 24 p. : ill. Co-authored by several contributors. Includes bibliography
summary The paper presents a project whose aim is to find better methods for the design of buildings like laboratories, office buildings, schools, hospitals etc., which have complex mechanical systems. The design of the mechanical infrastructure in such buildings is as important as the design of other architectural or construction parts. The fundamental idea of the project is to integrate design problems of the mechanical system into the design of the architectural and structural concepts of the entire building. This is based on the belief that using an expert system containing computer programs for the solution of design problems can support the whole design process and that the design of buildings having complex mechanical infrastructure can be qualitatively better and more efficient than the design with traditional methods
keywords architecture, expert systems, mechanical, systems, applications, design, building, construction
series CADline
last changed 1999/02/12 15:08

_id e234
authors Kalay, Yehuda E. and Harfmann, Anton C.
year 1985
title An Integrative Approach to Computer-Aided Design Education in Architecture
source February, 1985. [17] p. : [8] p. of ill
summary With the advent of CAD, schools of architecture are now obliged to prepare their graduates for using the emerging new design tools and methods in architectural practices of the future. In addition to this educational obligation, schools of architecture (possibly in partnership with practicing firms) are also the most appropriate agents for pursuing research in CAD that will lead to the development of better CAD software for use by the profession as a whole. To meet these two rather different obligations, two kinds of CAD education curricula are required: one which prepares tool- users, and another that prepares tool-builders. The first educates students about the use of CAD tools for the design of buildings, whereas the second educates them about the design of CAD tools themselves. The School of Architecture and Planning in SUNY at Buffalo has recognized these two obligations, and in Fall 1982 began to meet them by planning and implementing an integrated CAD environment. This environment now consists of 3 components: a tool-building sequence of courses, an advanced research program, and a general tool-users architectural curriculum. Students in the tool-building course sequence learn the principles of CAD and may, upon graduation, become researchers and the managers of CAD systems in practicing offices. While in school they form a pool of research assistants who may be employed in the research component of the CAD environment, thereby facilitating the design and development of advanced CAD tools. The research component, through its various projects, develops and provides state of the art tools to be used by practitioners as well as by students in the school, in such courses as architectural studio, environmental controls, performance programming, and basic design courses. Students in these courses who use the tools developed by the research group constitute the tool-users component of the CAD environment. While they are being educated in the methods they will be using throughout their professional careers, they also act as a 'real-world' laboratory for testing the software and thereby provide feedback to the research component. The School of Architecture and Planning in SUNY at Buffalo has been the first school to incorporate such a comprehensive CAD environment in its curriculum, thereby successfully fulfilling its obligation to train students in the innovative methods of design that will be used in architectural practices of the future, and at the same time making a significant contribution to the profession of architecture as a whole. This paper describes the methodology and illustrates the history of the CAD environment's implementation in the School
keywords CAD, architecture, education
series CADline
email
last changed 2003/06/02 13:58

_id 6db4
authors Karakatsanis, Andreas Georgiou
year 1985
title Floder: A Floor Designer Expert System
source Department of Civil Engineering, Carnegie Mellon University, Pittsburgh PA
summary The use of computers in structural design for the last two decades has been limited to algorithmic and procedural tasks. The use of expert system environments facilitates the implementation of conceptual tasks in computer programs. The goal of this study is to develop an expert system for the structural design of floor framings. FLODER, the resulting expert system, generates, analyzes, and evaluates floor framings for a given architectural plan. Framing generation consists of determination of the locations of structural elements in the architectural plan. Analysis involves an approximation of the dimensions of the slabs. Evaluation numerically ranks all generated framings using heuristic features for the alternatives. FLODER is implemented in OPS5 and LISP. The primary representations used are OPS5 production rules for the knowledge-base, and OPS5 working memory elements, for the context. Tasks amenable to algorithmic approaches are implemented in LISP. FLODER, even in its present state, can be viewed as a useful assistant to a designer. It can rapidly generate and evaluate alternative framings for a given architectural plan and thus increase the work productivity of its users [includes bibliography].
keywords Knowledge Base, Systems, Design, Architecture, Civil Engineering, Representation, Expert Systems, Floor Plans, Synthesis, Structures
series CADline
last changed 1999/02/15 15:27

_id e02f
authors Lenart, Mihaly
year 1985
title The Design of Buildings which Have Complex Mechanical Infrastructure using Expert Systems
doi https://doi.org/10.52842/conf.acadia.1985.052
source ACADIA Workshop ‘85 [ACADIA Conference Proceedings] Tempe (Arizona / USA) 2-3 November 1985, pp. 52-68
summary This paper presents a project under development at the University of Karlsruhe in which the author took part for two years. The aim of this project which was supported by the German Research Association (Deutsche Forschungsgemeinschaft) is to find better methods for the design of buildings having complex mechanical systems like laboratories, office buildings, schools, hospitals. etc. The design of the mechanical infrastructure in such buildings is as important as the design of other architectural or construction parts. The fundamental idea of the project is to consider design problems of the mechanical system as part of the design of the architectural and structural concepts of the entire building. This is based on the belief that the use of an expert system containing computer programs for the solution of design problems can support the whole design procedure and that the design of buildings having complex mechanical infrastructure can be qualitatively better and more efficient than the design with traditional methods.

series ACADIA
last changed 2022/06/07 07:52

_id ae09
authors Lieberman, Henry
year 1985
title There's More to Menu Systems Than Meets the Screen
source SIGGRAPH '85 Conference Proceedings. July, 1985. vol. 19 ; no. 3: pp. 181-189 : ill. includes bibliography
summary Love playing with those fancy menu-based graphical user interfaces, but afraid to program one yourself for your own application? Do windows seem opaque to you? Are you scared of Mice? Like what-you-see-is-what-you-get but don't know how to get-what-you-want-to-see on the screen? Everyone agrees using systems like graphical document illustrators, circuit designers, and iconic file systems is fun, but programming user interfaces for these systems isn't as much fun as it should be. Systems like the Lisp Machines, Xerox D- Machines, and Apple Macintosh provide powerful graphics primitives, but the casual applications designer is often stymied by the difficulty of mastering the details of window specification, multiple processes, interpreting mouse input, etc. This paper presents a kit called EZWin, which provides many services common to implementing a wide variety of interfaces, described as generalized editors for sets of graphical objects. An individual application is programmed simply by creating objects to represent the interface itself, each kind of graphical object, and each command. A unique interaction style is established which is insensitive to whether commands are chosen before or after their arguments. The system anticipates the types of arguments needed by commands preventing selection mistakes which are a common source of frustrating errors. Displayed objects are made 'mouse-sensitive' only if selection of the object is appropriate in the current context. The implementation of a graphical interface for a computer network simulation is described to illustrate how EZWin works
keywords user interface, computer graphics
series CADline
last changed 1999/02/12 15:09

_id 0397
authors Nadler, Edmond
year 1985
title Piecewise Linear Approximation on Triangulations of a Planar Region
source Reports in Pattern Analysis. [2], V, 76 p. :ill. May, 1985. No. 140. includes bibliography
summary For any triangulation of a given polygonal region, consider the piecewise linear least squares approximation of a given smooth function u. The problem is to characterize triangulations for which the global error of approximation is minimized for the number of triangles. The analogous problem in one dimension has been thoroughly analyzed, but in higher dimensions one has also to consider the shapes of the subregions, and not only their relative size. After establishing the existence of such an optimal triangulation, the local problem of best triangle shape is considered. Using an expression for the error of approximation involving the matrix H of second derivatives, the best shaped triangle is seen to be an equilateral transformed by a matrix related to H. This triangle is long in the direction of minimum curvature and narrow in the direction of maximum curvature, as one would expect. For the global problem, a series of two lower bounds on the approximation error are obtained, which suggest an asymptotic error estimate for optimal triangulation. The error estimate is shown to hold, and the conditions for attaining the lower bounds characterize the sizes and shapes of the triangles in the optimal triangulation. The shapes are seen to approach the optimal shapes described in the local analysis, and the errors on the triangles are seen to be asymptotically balanced
keywords triangulation, landscape, topology, computational geometry, computer graphics
series CADline
last changed 1999/02/12 15:09

_id 85d0
authors Peachey, Darwyn R.
year 1985
title Solid Texturing of Complex Surfaces
source SIGGRAPH '85 Conference Proceedings. July, 1985. vol. 19 ; no. 3: pp. 279-286 : ill. includes bibliography
summary Texturing is an effective method of simulating surface detail at relatively low cost. Traditionally, texture functions have been defined on the two-dimensional surface coordinate systems of individual surface patches. This paper introduces the notion of 'solid texturing.' Solid texturing uses texture functions defined throughout a region of three-dimensional space. Many nonhomogeneous materials, including wood and stone, may be more realistically rendered using solid texture functions. In addition, solid texturing can easily be applied to complex surfaces which are difficult to texture using two- dimensional texture functions. The paper gives examples of solid texture functions based on Fourier synthesis, stochastic texture models, projections of two-dimensional textures, and combinations of other solid textures
keywords shading, texture mapping, solid modeling, objects, computer graphics, rendering, visualization
series CADline
last changed 2003/06/02 10:24

_id 4f7a
authors Piegl, L.
year 1985
title The Sphere as a Rational Bezier Surface
source [4], 18 p. : ill. October, 1985. Preprint No. 07-13. includes bibliography
summary A method is developed for the efficient representation of spherical caps by using the rational Bezier scheme of Computer Aided Design. The technique is applied to describe special spherical patches such as the hemi-sphere, an octant of a sphere and the whole sphere. A geometric interpretation of quadratic curves and quadric patches is used in order to obtain an insight into the geometry inherent in the rational Bezier scheme and so to make easier the selection of the spherical patch out of the quadric primitives
keywords Bezier, curved surfaces, CAD
series CADline
last changed 2003/06/02 13:58

_id a36a
authors Rasdorf, William J.
year 1985
title Perspectives on Knowledge in Engineering Design
source Proceedings of the International Computers in Engineering Conference. Boston, MA: American Society of Mechanical Engineers, August, 1985. Vol. 2: pp. 249-253. CADLINE has abstract only
summary Of all the contributions of artificial intelligence (AI), expert systems show some of the most significant promise for engineering applications. Expert systems provide a framework for acquiring, representing, and using knowledge about a particular application's domain. The role of knowledge in engineering design merits closer attention so that AI- oriented computer-aided engineering (CAE) systems can be developed and maintained systematically. Because 'knowledge' in engineering applications is loosely defined, it is necessary to identify knowledge types and the correlations between them before widespread engineering design applications can be achieved. The types of domain knowledge; facts, procedures, judgments, and control; differ from the classes of that knowledge; creative, innovative, and routine. Feasible tasks for expert systems can be determined based on these types and classes of knowledge. Interpretive tasks require reasoning about a task in light of the knowledge available, while generative tasks create potential solutions to be tested against constraints. Only after classifying the domain by type and level can the engineer select an appropriate knowledge-engineering tool for the domain being considered. The critical features to be weighed after problem classification are knowledge representation techniques, control strategies, interface requirements, compatibility with traditional systems, and economic considerations. After considering all of these factors in the selection of the expert system tool, the engineer can then proceed with the acquisition of knowledge and the construction and the use of the expert system
keywords knowledge, AI, civil engineering, expert systems, CAE, representation
series CADline
last changed 2003/06/02 13:58

_id 8307
authors Rehak, Daniel R. and Howard, Craig H.
year 1985
title Interfacing Expert Systems with Design Databases in Integrated CAD Systems
source Computer Aided Design. November, 1985. vol. 17: pp. 443-454 : ill. includes bibliography
summary A model of a distributed network DBMS, using knowledge-base programming techniques, for interfacing KBS-to-DBMS is presented. In this model, the description of the data model of each KBS and DBMS component of the CAD system is represented as knowledge describing the components, making the components independent of each other. KADBASE, a prototype of such a flexible interface is demonstrating an approach to developing an integrated, distributed CAD system containing a variety of heterogeneous expert systems and design databases
keywords expert systems, design, database, user interface, integration, CAD
series CADline
last changed 2003/06/02 13:58

For more results click below:

this is page 0show page 1show page 2show page 3show page 4show page 5... show page 7HOMELOGIN (you are user _anon_551394 from group guest) CUMINCAD Papers Powered by SciX Open Publishing Services 1.002