bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of an interactive graphics system to the kinematic design of an artificial knee joint
Authors: Kaufman Roger E. 
Published: November 2005

KINSYN is an interactive general purpose computer system for the kinematic synthesis and analysis of mechanisms. It is applicable to kinematics problems ranging from the synthesis of spacecraft antenna deployment mechanisms to the design of folding high chairs. Features of KINSYN have been described in several recent publications.
The results shown in this paper were obtained during the first two or three trial runs on KINSYN. Of course, extensive work would remain to be done in order to apply these techniques to a practical artificial limb design, Nonetheless, the fact that so much useful design data can be obtained so readily with the aid of KINSYN indicates that it could be a significant aid in a physiological limb development program.
Some problems associated with interactive graphics in computer mediated tutorials
Authors: Weber J. C. , Linden D. J. , Frayer W. W. , Hagamen W. D. 
Published: November 2005

Whether one is talking about the verbal or graphic aspects of a computer mediated tutorial, there are two prime considerations. (1) How easy is it for the medical teacher to input the information? (2) How closely does the interaction with the student approximate a free format tutorial?
Our experience has gone through two distinct phases. For the first two years we worked with the IBM 1500 System and its associated language COURSEWRITER II (1). The 1500 has both a CRT with light pen and a random access, computer addressed, 35mm film strip projector.
For the past two years we have been working with APL/360 and an IBM 2741 Communications Terminal with no graphic capabilities. Using APL we have developed a new (author) programming language called ATS (A Tutorial System) (2,3,4).
Our purpose here today is to focus on the two aspects of a computer mediated tutorial already mentioned. Because of the nature of our personal experience, we would like to compare the problems (both the similarities and differences) associated with handling verbal and graphic input. The discussion will be divided into the following major topics. (1) A brief description of the 1500 System and our contributions to it.
This work has been documented previously. (2) Interfacing the medical author with the computer. (3) Providing the machine with the intelligence to handle free format interactions with the student. (4) A word about encoding verbal and graphic information.
A questionnaire
Authors: Lucido Anthony P. 
Published: November 2005

Comments from the editors
To determine the current status of some of the work being done by our readers I have put together a questionnaire. The questionnaire itself will be found following this short note. I would appreciate hearing from all persons currently doing some work in the area of computer graphics, or from anyone wishing to contribute information on a system in use. I will try to put all responses together (assuming someone out there responds) and summarize what is being done, as indicated by the returned questionnaires.
A retrospective (Panel)
Authors: Dunn Robert M. 
Published: November 2005

Graphics has been an industry for more than 15 years. Some workers trace its origins almost )0 years. The dramatic gains in silicon technology along with more highly developed understanding of the mathematics of graphics have transformed the architecture of computer graphic systems and produced a bewildering array of products and services.
This retrospective panel will try to put several key things in perspective. Dr. Alan Kay, recently of Atari Computer and currently an Apple Fellow, will characterize the role of graphics in the overall world of computing and information processing. Carl Machover of Machover Associates will trace the development of display technology and its employment in computer graphics systems. Dr. David Evan, Chairman of the Board of Evans and Sutherland will create the retrospective on our ability to produce realism in imagery. In turn Dr. Robert Sproull, Sutherland, Sutherland and Associates will trace the development of transformation that have found their way into silicon technology. Dr. James Foley, of George Washington University will track our progress in the technology of interaction, while Dr. Robin Forrest of the University of East Angela will trace geometric modeling and Dr. Ed Cattail, Director of Development at Lucasfilm will put our progress in animation in perspective.
Invisibility coherence for faster scan-line hidden surface algorithms
Authors: Crocker Gary A. 
Published: November 2005

Invisibility coherence is a new technique developed to decrease the time necessary to render shaded images by existing scan-line hidden surface algorithms. Invisibility coherence is a technique for removing portions of a scene that are not likely to be visible. If a large portion of the scene is invisible, as is often the case in three-dimensional computer graphics, the processing time eliminated may be substantial. Invisibility coherence takes advantage of the observation that a minimal amount of processing needs to be done on objects (polygons, patches, or surfaces) that will be hidden by other objects closer to the viewer. This fact can be used to increase the efficiency of current scan-line algorithms, including both polygon-based and parametrically curved surface-based algorithms.
Invisibility coherence was implemented and tested with the polygon hidden surface algorithm for constructive solid geometry developed by Peter Atherton [1]. The use of invisibility coherence substantially increases the efficiency of this scan-line algorithm. Invisibility coherence should work as well or even better with other scan-line hidden surface algorithms, such as the Lane-Carpenter, Whitted, and Blinn algorithms for parametrically curved surfaces [2]., or the Watkins, Romney, and Bouknight algorithms for polygons [3, 4, 5].
Beam tracing polygonal objects
Authors: Heckbert Paul S. , Hanrahan Pat 
Published: November 2005

Ray tracing has produced some of the most realistic computer generated pictures to date. They contain surface texturing, local shading, shadows, reflections and refractions. The major disadvantage of ray tracing results from its point-sampling approach. Because calculation proceeds
ab initio
at each pixel it is very CPU intensive and may contain noticeable aliasing artifacts. It is difficult to take advantage of spatial coherence because the shapes of reflections and refractions from curved surfaces are so complex.

In this paper we describe an algorithm that utilizes the spatial coherence of polygonal environments by combining features of both image and object space hidden surface algorithms. Instead of tracing infinitesimally thin rays of light, we sweep areas through a scene to form “beams.” This technique works particularly well for polygonal models since for this case the reflections are linear transformations, and refractions are often approximately so.
The recursive beam tracer begins by sweeping the projection plane through the scene. Beam-surface intersections are computed using two-dimensional polygonal set operations and an occlusion algorithm similar to the Weiler-Atherton hidden surface algorithm. For each beam-polygon intersection the beam is fragmented and new beams created for the reflected and transmitted swaths of light. These sub-beams are redirected with a 4×4 matrix transformation and recursively traced. This beam tree is an object space representation of the entire picture.
Since the priority of polygons is pre-determined, the final picture with reflections, refractions, shadows, and hidden surface removal is easily drawn. The coherence information enables very fast scan conversion and high resolution output. Image space edge and texture antialiasing methods can be applied.
Microcomputer graphics (Panel)
Authors: Pearlmutter Howard 
Published: November 2005

Ranging from home computers for entertainment and education to personal work-stations for design and presentation, microprocessor hardware spans the entire spectrum of graphic applications. Through live demonstrations of the latest and most popular hardware and software offerings, we hope to give you a feeling for the rapidly growing field of personal, “human scale” computing. The session will include a visual tour of the MacPaint package and the Quickdraw firmware on Apple's Macintosh personal computer, as well as brief demos of software for educational videogrames, low resolution typography and interactive, real-time animation.
Depending on audience questions, we might also take a look at issues and trends involved in mass marketing of software, personalization of technology and ownership of knowledge...and what the ramifications might be for the future of computer graphics and the human (-) computer dialogue.
The role and reality of graphics standards (Panel)
Authors: Warner James R. 
Published: November 2005

Graphics standards are formally sanctioned guidelines for graphics programming. Just as ANSI standards provide FORTRAN programmers with a common ground among compilers, the role of graphics standards is to define a set of common procedures or subroutines for developing graphics applications. The primary objectives underlying graphics standards are program portability and a common methodology for application program development.
Graphic standards are clearly desirable and efforts to bring them about are well underway. Nevertheless, the role of graphics standards must be matched with the reality of software development environments.
A common problem faced by all standards committees is the very long lead time required to arrive at consensus. Most standards groups are staffed by volunteers, chartered to develop standards models around generally-accepted current professional practices. Often, this is a time-consuming process relying on compromise and diplomacy and hampered by long intervals between meetings.
As a result, standards inevitably lag behind the industry, where competitive hardware vendors play leapfrog with one another, pushing the state of the art. Much of the concern surrounding standards implementations stems from the low level of standards literacy in the graphics user community. Beyond a vague understanding of functionality, most graphics software shoppers have little understanding on the different levels of standards, how to measure a good implementation, and methods of programming efficiently using a graphics standards methodology. As a result, standards-based packages face the difficult challenge of balancing the theoretical world of standards with the down to-earth needs of application developers working against deadlines.
This session will measure the several standards proposals now in the ANSI pipeline against the requirements and literacy level of the buying public. The evolution of a standard through ANSI and the implications of certification procedures will be presented and discussed. The problems of implementing a graphics standard will also be discussed, along with the general buying criteria to follow when shopping for standards-based graphics software.
GKS for imaging
Authors: Stoll Cliff 
Published: November 2005

By adopting the Graphical Kernel System (GKS), groups who manipulate pixelated images can take advantage of device independent graphics without giving up the functions which have traditionally been hardware dependent. Most of these functions, including image I/O, zoom, pan, lookup table manipulation, and cursor reading, are supported within GKS; several other functions, such as the use of multiple image planes and multiple look up tables, are accomodated by the GKS Escape and the Generalized Drawing Primitive (GDP). Because GKS has powerful inquire capabilities, it's possible to tightly customize applications code to a particular hardware display device. The inquire functions also can be used by an applications program to determine the hardware display size and thus avoid resampling of a pixelated image.
GKS thoroughly separates applications programs from device- dependencies; however, device drivers must still be written. The time and effort of writing device drivers can be largely eliminated by using a single programmable device driver, which is tailored to each device by a GRAPHCAP configuration file, in much the same way as TERMCAP is used by Berkeley Unix implementations.
Computer graphics research in Japanese Universities
Authors: Herr Laurin 
Published: November 2005

There is considerable research activity related to computer graphics within the Japanese academic community. However, little is known about it outside of Japan. Another problem is that some of the most interesting work being done is not called “Computer Graphics” and is therefore only reported in other fields such as “Precision Engineering” or “Image Processing.” Interpreting “Computer Graphics” broadly, this panel will survey the work of three leading Japanese researchers who will each briefly describe the history of computer graphics at their institutions, outline the level of staffing and equipment resources in their laboratories and report on their current areas of research activity. These presentations will be proceeded by the chairman's overview discussion about Japanese University research, in general. The panel will conclude with a question and answer period.
Professor Makoto Nagao, Department of Electrical Engineering, Kyoto University, Sakyo, Kyoto, Japan - The main thrust of research at Kyoto University has been in the field of digital image processing systems. Work began in 1965 on the problem of Japanese character recognition. One of the earliest digital processing systems in Japan was also designed. Working from beliefs about the human pattern recognition process, efforts were directed towards the development of a structural approach rather than mathematical theories which were popular during the early days of character recognition research. Current topics of interest include the modeling of more human-like image understanding functions, such as trial and error processes, knowledge-driven analysis processes and declaritive representation for image understanding. These can be summarized under the theme “Image Interpretation by Knowledge Presentation”.
Pyramidal parametrics
Authors: Williams Lance 
Published: November 2005

The mapping of images onto surfaces may substantially increase the realism and information content of computer-generated imagery. The projection of a flat source image onto a curved surface may involve sampling difficulties, however, which are compounded as the view of the surface changes. As the projected scale of the surface increases, interpolation between the original samples of the source image is necessary; as the scale is reduced, approximation of multiple samples in the source is required. Thus a constantly changing sampling window of view-dependent shape must traverse the source image.
To reduce the computation implied by these requirements, a set of prefiltered source images may be created. This approach can be applied to particular advantage in animation, where a large number of frames using the same source image must be generated. This paper advances a “pyramidal parametric” prefiltering and sampling geometry which minimizes aliasing effects and assures continuity within and between target images.
Although the mapping of texture onto surfaces is an excellent example of the process and provided the original motivation for its development, pyramidal parametric data structures admit of wider application. The aliasing of not only surface texture, but also highlights and even the surface representations themselves, may be minimized by pyramidal parametric means.
Towards a comprehensive user interface management system
Authors: Buxton W. , Lamb M. R. , Sherman D. , Smith K. C. 
Published: November 2005

A UIMS developed at the University of Toronto is presented. The system has two main components. The first is a set of tools to support the design and implementation of interactive graphics programs. The second is a run-time support package which handles interactions between the system and the user (things such as hit detection, event detection, screen updates, and procedure invocation), and provides facilities for logging user interactions for later protocol analysis.
The design/implementation tool is a preprocessor, called MENULAY, which permits the applications programmer to use interactive graphics techniques to design graphics menus and their functionality. The output of this preprocessor is high-level code which can be compiled with application-specific routines. User interactions with the resulting executable module are then handled by the run-time support package. The presentation works through an example from design to execution in a step-by-step manner.
The simulation of natural phenomena (Panel Session)
Authors: Blinn James , Gomez Julian , Max Nelson , Reeves William , Csuri Charles A. 
Published: November 2005

This panel will discuss the issues and the problems associated with the simulation of natural phenomena. This is a difficult area of research since it generally involves complex data bases and in many instances time variant phenomena. The computational loads can become enormous as one considers the physics or the mathematical modeling of structures.
Most items in nature, trees, clouds, fire and comets being some examples, have not been displayed realistically in computer graphics. This lack stems from a few different problems, all of which are significant. The first is the fact that realistic portrayals require large amounts of storage and consequently large compute time. Nature is able to create diverse detail at the most minute levels within an object of grandoise scale. The second problem is that of diversity of design within a given framework. For example, if a scene requires two dozen poplar trees, how does the designer construct trees that look different but are undeniably poplars? Humans typically become tired after the first few iterations of such a design process, with a resulting degradation in the subsequent models. Clearly, this problem applies to all of the phenomena mentioned above. Finally, there is a lack of models. First, second and third order representations are commonly used in computer graphics to model various kinds of surfaces and their boolean combinations. However, their applications to objects, which do not lend themselves well to being described as surfaces has not been addressed sufficiently.
Previous attempts at realism have dealt with the appearances of the surfaces being modeled, in terms of their illumination or relief. More recently, fractal methods have introduced a new degree of realism into terrain modeling systems. However, it appears that natural phenomena will require more research into the fundamental way things occur in nature, and in terms of computer graphics, their representation will build on previous work, but will still require new modeling techniques.
Anti-aliased line drawing using brush extrusion
Authors: Whitted Turner 
Published: November 2005

This algorithm draws lines on a gray-scale raster display by dragging a “brush” along the path of the line. The style of the line is determined by the properties of the brush. An anti-aliasing calculation is performed once for the brush itself and thereafter only a trivial additional operation is needed for each pixel through which the brush is dragged to yield an anti-aliased line.
There are few constraints on the size, shape, and attributes of the brush. Lines can be curved as well as straight, It is possible to produce lines with a three dimensional appearance.
The semantics of graphical input
Authors: Anson Ed 
Published: November 2005

Any graphical input device may be represented by a data structure, modified from time to time by actions in response to certain events, and the ability to cause certain events as part of its repertoire of actions. Portions of a device's state may be made visible to other devices in a controlled way, and the remainder hidden. Conversely, a device may make use of the visible portions of another device's state. Typically, the pattern of device interaction forms a hierarchy, but no device is part of any other. This provides for the interchangeability of a single device with a group of devices, and allows a single device to support the function of several others. Device independence is thus enhanced without the usual sacrifice of human factors considerations.
A group of devices defined in this manner can simulate any group of devices defined in the usual manner. Conversely, useful groups of devices may be defined, which cannot conveniently be simulated by the usual input semantics. The proposed semantic is thus more complete, and provides the additional benefit of a uniform language for describing both physical and virtual devices.
Human vision and computer graphics
Authors: Montalvo Fanya S. 
Published: November 2005

Is one picture really worth a thousand words? Why do cleverly designed graphic displays make visual information stand out more clearly with strikingly greater impact than numbers buried in pages of computer printout?
Graphic output devices shift the burden of integrating information generated by computers onto the human vision system: the sensory channel with the highest capacity for distributed parallel processing. The system consists of hundreds of successive two-dimensional arrays of millions of interconnected parallel computers. Perception seems instantaneous because we are not conscious of the massive amounts of computation that occur. What we consciously “see at a glance” is already a highly structured, synthesized, and summarized version of the actual light intensity mosaic that enters the retina.
We will demonstrate some results of the visual structuring that occurs in the human visual system, show why some features stand out instantaneously and others do not, and explain why knowledge of the human input device is crucial to the design of effective computer output devices and displays.
A terrain and cloud computer image generation model
Authors: Dungan William 
Published: November 2005

A method is presented that produces a realistic simulation of terrain using source data from the Defense Mapping Agency (DMA). Spatially compact objects are presently modeled with some success at realism. Because terrain is large in extent it exhibits special problems. These problems include: data base size and generation, masking priority, and shading.
An array of height values can be created from the DMA terrain file. Height is a single valued function of the array coordinate pair. The pair has implicit positional information. A masking priority algorithm is used which has no restriction on observer geometry. The algorithm searches the height array along the line of sight for the first visible position in the array. This approach requires no clipping or depth sorting of surface representations. The height array indices are used to access the pixel shade from a registered, orthonormal texture array. The use of texture provides a simple way to add nonlinear shading for a realistic representation with flexible data base generation.
Atmospheric attenuation is a method used to increase realism. Methods are in use which produce haze or fog with constant attenuation. The line-of-sight search is used to produce realistic clouds with spatially variable attenuation.
Terrain and clouds are adequately simulated using this method of modeling. The data structures of height and texture arrays are simple, easily generated, and make good use of storage resources. Resolving masking priority along the line of sight is a visible surface algorithm which has advantages over hidden surface algorithms. Realistic representations such as texture and atmospheric attenuation are used with some success.