bluuebunny/crossref_metadata_2025 huggingface dataset:
Hardware/software solutions for scientfic visualization at large reserach laboratories
Authors: Cook L. , Bancroft G. , Hussey K. , Dragon J. , Johnston W.
Published: November 2005

Good morning. My name is Linnea Cook from Lawrence Livermore Laboratory. This session is a panel session on hardware and software solutions for scientific visualization that are being pursued at some of the large research laboratories in the United States. This panel originated because I saw and other people at Los Alamos saw that we were pursuing different avenues of -- and quite vehemently -- pursuing different avenues of meeting our graphics needs. In Livermore in particular there was real strife for several years over graphics terminals versus graphics workstations. I thought that other people may benefit from seeing why people are pursuing some of the solutions that they are.Today there are five of us who are going to discuss a little bit about what the environment is that we work in and what we're each doing to solve the graphic needs in our environments, and also why we think our solution is the best.Each panelist is going to and make an eight to 10 minute statement to that effect. I will give each panelist a complete introduction when they get up to speak.I suppose I should tell you a little bit about who I am before we get started. My background is in math and computer science. I have a BS/MS in that, and I am currently a group leader for one of the computer science groups that supports one of our large physics divisions at Lawrence Livermore Laboratory. Part of the work we do is to support our physicists with good computer graphics and I have been leading the graphics workstation effort for my group.Our first panelist to speak is Gordon Bancroft. He is from NASA Ames and he has a BS in aeronautics. He's been at NASA for six years, and is currently task manager of workstation applications, as part of the fluid dynamics division. He's involved in the creation of applications for visualization of fluid dynamic simulation. He has been involved in some of the procurement that NASA has been doing. Gordon.
HDTV (Hi-Vision) computer graphics
Authors: Omura K. , Mochizuki R. , Tamegaya H. , Kawajuchi Y. , Miskowich D.
Published: November 2005

Good afternoon, ladies and gentlemen. We'll begin the panel session -- HDTV Computer Graphics. I am Koichi Omura at Osaka Municipal University. I am the chair of this panel. At first I'd like to thank SIGGRAPH, giving us the opportunity speaking today.The first presentation is by Mr. Ryou Mochizuki. He is the controller of NHK Engineering Service Corporation. He will discuss the compact disc application of HDTV, and after that he will present the brief introduction of HDTV.
1989 computer graphics education directory
Authors: Ferguson E.
Published: November 2005

This is SIGGRAPH's fourth directory of college-level computer graphics education, covering courses in computer graphics in several different subjects. This directory is a single source of computer graphics course information. If you are a student entering college or considering a change of studies, a professional considering broadening your skills, or an educator seeking broader contacts in graphics among your peers, this directory is designed for you.We compiled the directory from the responses to a questionnaire sent out this spring, and it is completely updated since the last edition. The responses were separated by topic according to information received on the questionnaire and our perception of the course's audience. The placement of some courses may not be precise, so you may be advised to use more than one directory list in searching for an interesting course. For example, if you are interested in graphics for architects you should consult the Arts, Architecture and Design listings, but you might also find useful information in the list on Engineering, CAD/CAM and Drafting. You should follow up interesting entries by contacting the school directly for the many details of schedule, cost and admission which are not included here. We should point out that our listing is not complete since we do not know of all the computer graphics courses being taught, and some courses listed in previous directories are not here since no information was received on them.The course information we received was placed in individual lists by the following criteria. The Concepts and Systems list contains courses covering general concepts in computer graphics and systems for producing graphics; such courses are often found in Computer Science or EECS programs and have no particular application orientation. The Engineering, CAD/CAM and Drafting list contains courses which seem to be oriented toward applications in these areas. For CAD/CAM and Drafting courses, this is rather easy to tell, while the engineering orientation is inferred from a location in an Engineering program with no other information, or from a title such as "Engineering Computer Graphics." Many engineering programs, however, have courses which seem to fit the Concepts and Systems category most closely and so are listed there. The other lists are fairly easily categorized, except for some problems determining where to place courses in Design; here the home program is usually the determining factor.
The virtual erector set: dynamic simulation with linear recursive constraint propagation
Authors: Schröder Peter , Zeltzer David
Published: November 2005

We have implemented an algorithm for rigid body dynamics which unifies the advantages of linear recursive algorithms with the advantages of earlier linear algebra based constraint force approaches. No restriction is placed on the joints between links. The algorithm is numerically robust and can deal with arbitrary trees of bodies, including kinematic loops. Motion as well as force constraints on the dynamic behavior of any member of the linkage can be added easily. Through the use of
spatial algebra
notation---including our extension to account for
spatial position
---the mathematical expressions are simplified and more efficient to execute. The algorithm has been implemented on workstation class machines and performs at interactive speeds.
Reality built for two: a virtual reality tool
Authors: Blanchard Chuck , Burgess Scott , Harvill Young , Lanier Jaron , Lasko Ann , Oberman Mark , Teitel Mike
Published: November 2005

Researchers have been working with head mounted displays and virtual reality (VR) since 1965 when Ivan Sutherland published his first paper on the subject
1
. This work has centered on a single user within virtual space. The literature has covered applications such as telerobotics, virtual control panels, architectural simulation and scientific visualization.Several factors now militate toward broadening the range of VR applications: developments in hardware and software, as well as a growing readiness in many fields to incorporate VR. User interface constraints of VR systems need to change in response to this changing user profile. Design of environments and behaviors in virtual worlds should be simple and accessible to experts in many fields. With the advent of multi-user systems, communications will become a major application of virtual reality.VPL has recently developed a system that allows more than one user to share a virtual space. The forms and behaviors of virtual worlds are specified graphically, so that non-programmers can design them. The system, called Reality Built for Two, will be demonstrated at the Symposium on Interactive 3D Graphics.
T-buffer: fast visualization of relativistic effects in space-time
Authors: Hsiung Ping-Kang , Thibadeau Robert H. , Wu Michael
Published: November 2005

We have developed an innovative ray-tracing simulation algorithm to describe
R
elativistic
E
ffects in
S
pace
T
ime ("REST"). Our algorithm, called
REST-frame
, models light rays that have assumed infinite speed in conventional ray-tracing to have a
finite
speed in spacetime, and uses the non-Newtonian Lorentz Transformation to relate measurements of a single event in different inertial coordinate systems
(inertial frames)
. Our earlier work [5][6][7] explored the power of
REST-frame
as an
experimentation tool
to study the rich visual properties in natural world modeled by Special Relativity. Non-intuitive images of the anisotropic deformation ("warping") of space, the intensity concentration/spreading of light sources in spacetime, and the relativistic Doppler shift were visualized from our simulations.
Visualization methods and simulation steering for a 3D turbulence model of Lake Erie
Authors: Marshall Robert , Kempf Jill , Dyer Scott , Yen Chieh-Cheng
Published: November 2005

A computational model of Lake Erie serves as a framework for a study of visualization techniques and display methods. Various display methods are used to examine the 3D data. The methods use primitive representations of polygons, volumes, lines and particles. The display methods also incorporate stereo imagery and animation. Three techniques of integrating the control of the computationl model and the display of images are discussed. These visualization techniques are post-processing, tracking and steering. A distributed software environment is used which implements these visualization techniques and display methods. The technique of steering is emphasized with a description of the software requirements and examples. A significant increase in productivity and comprehension is shown when steering is used.
Physical modeling with B-spline surfaces for interactive design and animation
Authors: Thingvold Jeffrey A. , Cohen Elaine
Published: November 2005

Physically based modeling has recently become a subject of widespread interest. This paper defines a model of elastic and plastic B-spline surfaces which supports both animation and design operations, including the interference detection, within the "Eplastics"/Alpha_1 modeling environment. We develop "refinement" operations for spring and hinge B-spline models which are compatible with the physics and the mathematics of B-spline models, including refinement. It is also a step towards a more continuous physical representation of a physical model than the more standard discretized geometry point mass models. We present some interactive operations currently in real-time and some which could be real-time with further optimization and use of multiple processors on machines such as the SGI Iris 4D/240GTX. A movie is used to illustrate the results.
The ThingWorld modeling system: virtual sculpting by modal forces
Authors: Sclaroff Stanley E. , Pentland Alex , Essa Irfan , Friedmann Martin , Horowitz Bradley
Published: November 2005

We describe a real-time solid modeling system that is based on the physical analogy of forming clay by applying forces. The system is implemented by simulating real materials as they react to user-supplied forces. Unlike other physically-based modeling approaches, the Thingworld system allows the user to restrict forming action to simple global deformations during the initial "roughing in" phase of modeling, and then later concern themselves with detailing. The Thingworld system also allows users to automatically model existing objects by using measurements taken from the object's surface. These measurements are used to generate artificial forces that mold the computer model much as a human would mold a clay model. Timed examples for constructing solid models are shown.
Distributing display lists on a multicomputer
Authors: Ellsworth David , Good Howard , Tebbs Brice
Published: November 2005

We have developed techniques for distributing a hierarchical display list from a PHIGS-like library across a multicomputer. By storing a portion of the database at each processor, inter-processor communication is reduced. This reduction promises traversal of the display list at rates supporting rendering speeds of one million polygons/second or more, as we hope to achieve on our new machine, Pixel-Planes 5 (under construction). Our distribution techniques support order-dependent primitives and allow general display list editing.
Snap-dragging in three dimensions
Authors: Bier Eric A.
Published: November 2005

A large portion of the user interface in interactive solid modeling systems is devoted to the problem of placing and orienting objects in three dimensions. In particular, many operations must be provided for selecting control points, curves and surfaces, and for translating, rotating and scaling scene components into precise relationships with other scene components. By factoring these operations carefully, it is possible to provide the desired functionality so as to reduce both the size of the user interface and the time that it takes to use it. With snap-dragging, the user takes advantage of three main elements that work together: a general-purpose gravity function, alignment objects that can be created many at a time, and smooth-motion affine transformations. Scene composition is achieved in a single perspective view using a mouse and keyboard. With 19 mouse commands, 15 keyboard commands, 5 menus of numbers, and 1 single-level menu of numerical transformations, this user interface has fewer commands and requires fewer keystrokes than the skitters and jacks technique reported earlier.
Interactive real-time articulated figure manipulation using multiple kinematic constraints
Authors: Phillips Cary B. , Zhao Jianmin , Badler Norman I.
Published: November 2005

In this paper, we describe an interactive system for positioning articulated figures which uses a 3D direct manipulation technique to provide input to an inverse kinematics algorithm running in real time. The system allows the user to manipulate highly articulated figures, such as human figure models, by interactively dragging 3D "reach goals." The user may also define multiple "reach constraints" which are enforced during the manipulation. The 3D direct manipulation interface provides a good mechanism for control of the inverse kinematics algorithm and helps it to overcome problems with redundancies and singularities which occur with figures of many degrees of freedom. We use an adaptive technique for evaluating the constraints which allows us to ensure that only a certain user-controllable amount of time will be consumed by the inverse kinematics algorithm at each iteration of the manipulation process. This technique is also sensitive to the time it takes to redraw the screen, so it prevents the frame display rate of the direct manipulation from become too slow for interactive control.
A high level language extension for creating and controlling dynamic pictures
Authors: Pfister Gregory F.
Published: November 2005

DALI (Display Algorithm Language Interpreter) is a special purpose high level programming language extension for the creation and control of dynamic pictures which exhibit complex static and dynamic interactions among their elements. DALI allows complex organizations of interpolated (“smooth”) change, discrete (“sudden”) change, and change to the structure of a picture to be generated in a modular way, in the sense that picture elements determine their own behavior and hence manner of change in a local manner.

DALI pictures are composed of elements called
picture modules
. These are analogous to processes or procedural activations, and contain arbitrary event-driven procedures called
daemons
. Daemons, which are user-written, run under the control of
scheduling rules
based on the functional dependence of daemons on one another. These rules result in smooth inter-daemon (process) communication and cooperation with no implicit or explicit reference to semaphores or other synchronization primitives.
A preliminary step towards a language for picture control in a real-time mode
Authors: Katz Lou , Etra Bill
Published: November 2005

With the proliferation of extremely complex analog systems for the control of television images it has become evident that some more efficient system has to be found for dealing with the mire of knobs, switches, levers, and patch cords which make up any video processing device. In planning an attack on this situation, we soon realized that a major aspect of the problem is a linquistic one. Television has only a few terms which deal with the almost infinite number of effects possible in any given system. The specification of wipes, fades, dissolves, keys, etc. tells one the process used, but does not go into great detail as to what it looks like on the screen. A circle wipe, for instance, may start in any part of the screen, have an edge in any of several degrees of softness, may be modulated by a wide range of frequencies, and may have a number of outlines around it in any combination of colors. Given these technical capabilities, the problem of how to catalog the possible effects and how to specify them was approached in terms of a description based on a Cartesian coordinate system representation of the multidimensional video space.

The use of such a coordinate system has given us several advantages. The first is that there is a large body of existing work dealing with physical movements along orthogonal axes. Secondly, image color in television can be measured or specified in terms of phase shifts from 0 to 360 degrees in a planar reference axis system. Another consideration which makes this description natural is that it is standard for zero voltage on a CRT display to be center screen, thus defining our origin and relating it in a simple way to the physical control values. With this as our point of departure we embarked on our work with the clear realization that, because the dimensions and variability of the system were almost infinite, due to the unconstrained combination of analog patches and digital programming, some severe restraint would be necessary in order to make the results meaningful.
Control structures for performance graphics
Authors: DeFanti T. A. , Sandin D. J. , Ainsworth R. A.
Published: November 2005

Responsive control structures allow graphics systems to be used as performance instruments. Control structures are a design element of a system—while they are manipulated by the user or performer, they exist primarily as a result of the system designer's software and hardware engineering.

For example, the control structure of the telephone system allows ten sequential inputs to connect your phone to almost any other in the world. The power of this structure is independent of the specific user control device. Dials, push buttons, tones and clicks can all be used as inputs.

While physical controls provide inputs, control structures determine what these inputs do.
On the design and use of graphics-oriented continuous system simulation languages (CSSL)
Authors: Herring Travis L.
Published: November 2005

Some of the features of CSSL languages are discussed, followed by a discussion of the suitability of CSSL as a basis for an interactive graphics programming system. Features of a graphics implementation of CSSL (GCSSL) are then described. It is noted that GCSSL has applications well beyond that suggested by the fact that it is based on CSSL. Some of these applications are graphics program development, computer animated displays and movies, and the general area of scientific computing. Suggestions for future developments are mentioned.
Computer graphics in medicine
Authors: Mishelevich David J.
Published: November 2005

The objective of this paper is not to present a catalog of current or potential applications of computer graphics in medicine, but rather to raise some basic key issues for consideration. The six theses which I am exploring are:

1. Iconic Communication must be the ultimate objective of computer graphics;

2. Possibilities for dynamism and interaction provide exciting dimensions for graphic presentation;

3. Use of the Optimality Principle can assist in promoting rapid progress;

4. The Building Block Principle is useful for system development and application as well as initially getting started;

5. Adherence to simple design principles can enhance graphic effectiveness; and

6. Cost-Benefit is a key factor in graphics system evaluation and utility.

Each of these theses will be considered in turn in an effort to lay the groundwork for discussing, analyzing and evaluating computer graphics in medicine. It must, of course, be noted that all principles discussed here are pertinent to computer graphics in general and not just related to medicine. In medicine however, the problems are often more difficult to deal with and the consequences greater. Thus interdisciplinary communication is critical if the problems are to be solved.
Computer quantitation of ventricular arrhythmias
Authors: Battersby Edward J.
Published: November 2005

This paper describes a system designed around a small laboratory computer directed toward the task of quantitating ventricular arrhythmias in support of pharmacologic research. This class of disorders of cardiac rhythm is so designated because the site of electrical origin is in the ventricles of the heart. In certain clinical states, the new appearance of or increase in frequency of beats of this type is often a herald of more serious, and at times, catastrophic rhythm disturbances. The presence of frequent ventricular beats or of runs of such beats in general usually motivates the Cardiologist to use drugs to suppress these rhythm disturbances. This system is designed to facilitate the data processing task associated with the investigation of such drugs.
Interactive computer graphics in medical information retrieval and classification
Authors: Thompson David A.
Published: November 2005

The size of the body of medical literature is vast and growing at a rapid rate. The National Library of Medicine collection contains about two million items and at the present rate of growth will double in about 7 years.

Attempts to improve the access to medical literature by professional practitioners, para-medical personnel, and life science researchers has principally included the MEDLARS service, a telephone/mail query service operating in batch mode; and interactive retrieval services operating on-line over long distance telephone lines such as AIM-TWX, developed by Systems Development Corporation.
Application of pattern recognition to shock-Trauma studies
Authors: Cowley R. , Turney S. , Copes W. , Sperrazza J. , Masaitis C. , Sacco W.
Published: November 2005

This paper reports the results of a study to determine
pattern vectors
(Profiles) composed of physiological and biochemical measurements which reflect the severity of injury to
traumatized
individuals. Profiles, selected by clinicians at the University of Maryland Center for the Study of Trauma, were obtained from the Center data bank and subjected to pattern analyses using OLPARS, an on-line pattern analysis and recognition system, located at Rome Air Development Center, Rome, New York. Prognosis regions were delineated in the
Eigenvector Plane
and the
Discriminant Plane
. The time courses of individual patients were plotted in the Eigenvector Plane.
Biological primitives
Authors: DeLand E. C.
Published: November 2005

In developing the graphics computer system BIOMOD, we were concerned primarily with the user-system interface. Rather than developing a formal higher-level language specific to modeling in biology, it appeared more fruitful to examine empirically the activities of the modeling process, and to attempt to design so that these activities would be simple to perform.

Unfortunately, however, it still functioned easily only for chemists, mathematicians, and programmers; a biologist would still not write FORTRAN or differential equations to describe the basic functions—for example, a neuron—of his problem. We would like, therefore, to describe a set of basic biological functions, or primitives, which can have unambiguous definitions and can be parameterized as required in a straightforward, clear way so that they can be called from the library and used in a new problem context. An extension of this concept is to prepare programmed modules, such as a capillary resistance bed, or models, such as a model of the four-chambered heart as a pump, which could be used as required. However, these latter modeling units are not easily parameterized and are usually too individually stylized to carry over from model to model. Instead, we have been concerned with more basic units which can be standardized, as will be described in subsequent sections of this paper. We first briefly describe the BIOMOD system itself.
Man and machine in medical electronics
Authors: Shaw Peter J.
Published: November 2005

Advances in computer technology have come a long way in the past twenty years. By far and away, the largest use of the computer is as a data bank for accounting, inventory and other such type business record keeping procedures. Only recently has man begun to channel his vast resources in computer technology towards the field of medicine. And even here, we now find the great preponderance of computers used exclusively for information retrieval and storage.

The purpose of this paper will be to try to show how simple, inexpensive, man-to-computer interfaces can successfully be used to greatly improve the efficiency and effectiveness of those involved in the healing arts.
ESP
3
Authors: Shapiro Linda G.
Published: November 2005

Most graphics languages are composed of a primitive set of commands which allow for the creation and manipulation of graphical objects. These commands are generally at a low level, in that each command causes one operation to be performed. Often the commands are to subroutines embedded in an algorithmic language so that the arithmetic and control features of the higher level language may be used.ESP
3
(Extended SNOBOL Picture Pattern Processor) is a new high-level graphics and pattern recognition language. ESP
3
was designed in an effort to provide simple, natural, and efficient manipulation of line drawings. ESP
3
differs from present graphics languages in the following ways:1) It provides a high-level method for picture construction. The evaluation of a picture expression (analagous to the SNOBOL4 string-valued expression) causes the construction of a picture.2) It provides extensive referencing facilities for naming and accessing points, subpictures, and attributes of pictures.3) It provides predicates for testing attributes of and relationships among pictures and points.4) It provides a means for defining picture patterns that describe classes of line drawings in much the same way that SNOBOL4 patterns describe classes of strings. Picture pattern matching is a built-in facility.ESP
3
is based on the premise that structural descriptions are an essential part of both picture construction and pattern recognition. The concept of a structural description of a picture has its origin with the linguistic-approach to pattern recognition. In the linguistic approach, formal grammars are used as a mechanism for picture description. [Kirsch (1964), Narasimhan (1964, 1966,1970), Anderson (1968), Evans (1968), Miller and Shaw (1969), Fu and Swain (1971), Shaw (1970, 1972), Chien and Ribak (1972), Thomason and Gonzalez (1975)]. Stanton (1970) described a graphics language based on linguistic pattern recognition. ESP
3
incorporates and extends many ideas from the above work, and includes all of the features of SNOBOL4 to provide a high-level graphics and pattern recognition language. Some suggested applications of ESP
3
are the generation of graphical output, AI programs with imaging capabilities, pattern recognition systems, and scene analysis programs.This paper will describe picture construction and pattern recognition in ESP with emphasis on picture construction. Some tests performed with an experimental version of ESP
3
will also be discussed. For a more detailed description of ESP
3
, see Shapiro (1974).
Computer animation
Authors: Csuri Charles
Published: November 2005

A comprehensive 3-D real-time computer animation system is based upon a broad range of research activities in the field of computer graphics. In many ways the requirements for such a system are more challenging and complex than for other graphics systems. This is particularly true if one builds a language and a system which is truly user oriented and which has viable production capabilities for researchers and film makers. Too often systems which are the result of a research experiment in hardware or software design do not go beyond a beautiful demonstration of potentialities. Such experimentation is essential to advance the state of knowledge but if computer animation is to become a new research and production instrument we must, in addition, provide more examples of useable systems.Although each of the following topics are aspects of a real-time animation environment deserving a detailed explanation, they will be dealt with in a way to introduce to the reader basic requirements and problems. The topics are:I. STATE OF THE ART SYSTEMS, AND LANGUAGES• Used as references and as a basis of comparison.II. AN ANIMATION ENVIRONMENT• Several systems and languages are being implemented to run under RSX-11/D on our PDP-11/45 computer.A. VISIBLE SURFACE SYSTEM• Allan Myers' algorithm• VILAN (VIsual LANguage)B. GRAPHICS SUPPORT SYSTEM• Manfred Knemeyer's system for handling hardware devices, data structures, management of transformations and time, and memory management for the graphics buffer.C. ANIMA• A new graphics programming language has been designed and is being implemented.D. DATA GENERATION SYSTEM• Some approaches to problems are briefly discussed.III. DISPLAY HARDWARE AND GRAPHICS ALGORITHMS• The problems presented by the order of transformations in an algorithm are briefly described.IV. HIGH PERFORMANCE GRAPHICS• some speculations
Three-dimensional human display model
Authors: Potter T. E. , Willmert K. D.
Published: November 2005

A two-dimensional computer graphic display of a three-dimensional model depicting a human being is presented. The major body segments of the model are represented as non-uniform elliptic cylinders. The shadow outlines of these cylinders are displayed on the terminal screen and connected by circular arcs and straight lines to produce a realistic representation of a human being in any position.This human model was developed for the display of results of three-dimensional simulation programs which calculate the positions of an occupant during vehicle impact. However, it is well suited to any other type of human motion. The approach allows the user to select the viewing orientation and was designed for low cost computer and graphic terminal systems.
Plants, fractals, and formal languages
Authors: Smith Alvy Ray
Published: November 2005

Although fractal models of natural phenomena have received much attention recently, there are other models of complex natural objects which have been around longer in Computer Imagery but are not widely known. These are procedural models of plants and trees. An interesting class of these models is presented here which handles plant growth, sports an efficient data representation, and has a high “database amplification” factor. It is based on an extension of the well-known formal languages of symbol strings to the lesser-known formal languages of labeled graphs. It is so tempting to describe these plant models as “fractal” that the similarities of this class of models with fractal models are explored in an attempt at rapprochement. The models are not fractal so the common parts of fractal theory and plant theory are abstracted to form a class of objects, the
graftals
. This class may prove to be of great interest to the future of Computer Imagery. Determinism is shown to provide adequate complexity, whereas randomness is only convenient and often inefficient. Finally, a nonfractal, nongraftal family of trees by Bill Reeves is introduced to emphasize some of the paper's nongrammatical themes.
Global and local deformations of solid primitives
Authors: Barr Alan H.
Published: November 2005

New hierarchical solid modeling operations are developed, which simulate twisting, bending, tapering, or similar transformations of geometric objects. The chief result is that the normal vector of an arbitrarily deformed smooth surface can be calculated directly from the surface normal vector of the undeformed surface and a transformation matrix. Deformations are easily combined in a hierarchical structure, creating complex objects from simpler ones. The position vectors and normal vectors in the simpler objects are used to calculate the position and normal vectors in the more complex forms; each level in the deformation hierarchy requires an additional matrix multiply for the normal vector calculation. Deformations are important and highly intuitive operations which ease the control and rendering of large families of three-dimensional geometric shapes.
Interpolating splines with local tension, continuity, and bias control
Authors: Kochanek Doris H. U. , Bartels Richard H.
Published: November 2005

This paper presents a new method for using cubic interpolating splines in a key frame animation system. Three control parameters allow the animator to change the tension, continuity, and bias of the splines. Each of these three parameters can be used for either local or global control. Our technique produces a very general class of interpolating cubic splines which includes the cardinal splines as a proper subset.
Automatic synthesis of graphical object descriptions
Authors: Friedell Mark
Published: November 2005

A technique is presented for automatically synthesizing graphical object descriptions from high-level specifications. The technique includes mechanisms for describing, selecting, and combining primitive elements of object descriptions. Underlying these mechanisms are a referential framework for describing information used in the construction of object descriptions and a computational model of the object-synthesis process.

This technique has been implemented in two prototype systems to synthesize object descriptions in near-real time. One system creates graphical displays of information that resides in a conventional database. The other system is a computer graphicist's tool for creating backgrounds of complex, three-dimensional scenes.
Computing in the fast lane (Panel)
Authors: Weinberg Richard
Published: November 2005

The fast generation of complex synthetic images by digital computing systems requires immense computational resources, which can be provided by several means.

Supercomputers, flight simulators and special purpose image synthesis architectures will be examined and compared by the panel. Each of these systems represents the very high end of the computational spectrum, with performance measured in hundreds of millions of operations per second.
A hardware stochastic interpolator for raster displays
Authors: Piper Timothy S. , Fournier Alain
Published: November 2005

Stochastic modeling has found uses so far mainly for expensive very realistic graphics display. The cost of rendering is not intrinsic to the technique, but mainly due to the high resolution and the sophisticated display techniques which accompany it. We describe here a basic tool for a less expensive approach to stochastic modeling which is designed for a more “down to earth” type of application, and brings the display of stochastic models nearer to real-time.

A special purpose board for stochastic interpolation has been built, which can generate an array of up to 129×129 12 bit stochastic values to be used by the rest of the display system as a texture source, or for more elaborate algorithms. The board functions as a coprocessor in a traditional frame buffer system, and includes a micro-coded bit-slice processor, a multiplier, special hardware to generate uniformly distributed random numbers, memory to store a look-up table for random numbers with the required distribution, and two buffers for the resulting arrays.

The current implementation generates values at less than 4 microseconds per point, and in conjunction with a standard graphics processor can display nearly 10000 stochastic points in real-time, or can update a full screen of stochastic values in less than one second. Illustrations are given of the output of the board and of pictures and animations generated with it.
International technology transfer (Panel)
Authors: Machover Carl
Published: November 2005

For the past two and one half decades, USA suppliers have generally dominated the computer graphics marketplace, providing an estimated 90 percent of computer graphics shipments worldwide. In the past few years, however, a number of non-USA sources have begun to develop products which not only have captured a growing percentage of their domestic markets, but also have begun to be competitive worldwide. USA companies have increasingly turned to non-USA sources for licenses and products. This panel brings together executives from European, Asian and South African companies to discuss the growing exchange of computer graphics technology among USA and non-USA suppliers.
An analytic visible surface algorithm for independent pixel processing
Authors: Catmull Edwin
Published: November 2005

An algorithm is presented that solves the visible surface problem at each pixel independently. This allows motion blur and depth of field blurring to be integrated into the algorithm. It also allows parallel processing. The algorithm works on large numbers of polygons. An analytic Gaussian filter is used. The filter can be elongated or scaled differently for each polygon to adjust for its speed or distance from the focal plane. This is achieved by shrinking or scaling the polygon prior to solving the hidden surface problem so that blurring is correctly presented when objects obscure each other.
International market opportunities (Panel)
Authors: Husby Philip G.
Published: November 2005

The Panel will discuss the subject of entering foreign markets with the objective of increasing company revenues. The first panelist will discuss the general benefits of international trade and the potential for the computer graphics industry. Foreign markets which hold the greatest promise for penetration will be identified and an overview of the regulations governing the exports of the industry will be presented. The discussion will conclude with the identification of select services offered to U.S. firms by the U.S. Department of Commerce for the purpose of assisting companies in reaching foreign markets.
An adaptive subdivision algorithm and parallel architecture for realistic image synthesis
Authors: Dippé Mark , Swensen John
Published: November 2005

An algorithm for computing ray traced pictures is presented, which adaptively subdivides scenes into
S
subregions, each with roughly uniform load. It can yield speedups of
O
(
S
2/3
) over the standard algorithm.

This algorithm can be mapped onto a parallel architecture consisting of a three dimensional array of computers which operate autonomously. The algorithm and architecture are well matched, so that communication overhead is small with respect to the computation, for sufficiently complex scenes. This allows close to linear improvements in performance, even with thousands of computers, in addition to the improvement due to subdivision.

The algorithm and architecture provide mechanisms to gracefully degrade in response to excessive load. The architecture also tolerates failures of computers without errors in the computation.
A system for algorithm animation
Authors: Brown Marc H. , Sedgewick Robert
Published: November 2005

A software environment is described which provides facilities at a variety of levels for “animating” algorithms: exposing properties of programs by displaying multiple dynamic views of the program and associated data structures. The system is operational on a network of graphics-based, personal workstations and has been used successfully in several applications for teaching and research in computer science and mathematics. In this paper, we outline the conceptual framework that we have developed for animating algorithms, describe the system that we have implemented, and give several examples drawn from the host of algorithms that we have animated.
Priority windows
Authors: Littlefield Richard J.
Published: November 2005

Priority windows are a basic tool for interactive graphics, underlying such techniques as pop-up menus and single screen viewing and control of multiple contexts. Most implementations of priority windows are raster oriented, frequently relying on special hardware capabilities such as high speed rasterops. This paper discusses an alternative approach, based on vector clipping, that works with any display device capable of drawing and erasing vectors. It has been used to implement a general purpose windowing package that supports application programs using a vector graphics model. It is device independent, running without change on a desktop computer with integral graphics and on a timesharing system with a peripheral display. In purely device independent form, windowing performance depends on host processing speed and communications bandwidth. Techniques are described for improving responsiveness by overlapping some windowing computations with the user's think time. Performance improvements based on extended device capabilities such as rectangular fill, hardware characters, and local display lists with clipping are also suggested.

Presentation of this paper included a videotape showing the dynamics of one application on an HP-9000 desktop computer and on a VAX 11/780 plus Ramtek Marquis configuration.
Computer graphics in commercial and broadcast production (Panel)
Authors: Rosendahl Carl
Published: November 2005

The goal of this panel is to acquaint the listener with what is perhaps the most visible area of computer graphics - the use of animation in television and motion pictures

Creating animation for commercial use is subject to many factors outside of the animator's control. Pieces are constrained by deadlines and budgets and yet must be “ new, fresh and different” in order to satisfy the client. The speakers on the panel represent four of the leading computer animation production houses and are well acquainted with having to work with these constraints while still delivering work of the highest possible quality. In addition to showing some of their work, the participants will discuss methods for creating animation for commercial use.
Modeling the interaction of light between diffuse surfaces
Authors: Goral Cindy M. , Torrance Kenneth E. , Greenberg Donald P. , Battaile Bennett
Published: November 2005

A method is described which models the interaction of light between diffusely reflecting surfaces. Current light reflection models used in computer graphics do not account for the object-to-object reflection between diffuse surfaces, and thus incorrectly compute the global illumination effects. The new procedure, based on methods used in thermal engineering, includes the effects of diffuse light sources of finite area, as well as the “color-bleeding” effects which are caused by the diffuse reflections. A simple environment is used to illustrate these simulated effects and is presented with photographs of a physical model. The procedure is applicable to environments composed of ideal diffuse reflectors and can account for direct illumination from a variety of light sources. The resultant surface intensities are independent of observer position, and thus environments can be preprocessed for dynamic sequences.
A family of new algorithms for soft filling
Authors: Fishkin Kenneth P. , Barsky Brian A.
Published: November 2005

Soft filling
algorithms change the color of an anti-aliased region, maintaining the anti-aliasing of the region. The two published algorithms for soft filling work only if the foreground region is anti-aliased against a black background. This paper presents three new algorithms. The first fills against a region consisting of any
two
distinct colors, and is faster than the published algorithms on a pixel-by-pixel basis for an RGB frame buffer; the second fills against a region composed of
three
distinct colors; and the third fills against a region composed of
four
distinct colors. As the power of the algorithms increases, so do the number of assumptions they make, and the computational cost.
A programmer's interface to graphics dynamics
Authors: Turner Joshua U.
Published: November 2005

The term “graphics dynamics” is used in this paper to describe a capability which permits the application programmer to specify a relationship between various graphics input devices and aspects of the graphics output presentation. Subsequent use of the input devices results in continuous real-time changes to the picture. An experimental graphics system is described, in which a powerful programmer's interface to graphics dynamics was implemented. This interface appears suitable for use as an extension to any of the existing standards and standards proposals, including, CORE, GKS, and PHIGS.
Lighting controls for synthetic images
Authors: Warn David R.
Published: November 2005

The traditional point source light used for synthetic image generation provides no adjustments other than position, and this severely limits the effects that can be achieved. It can be difficult to highlight particular features of an object. This paper describes new lighting controls and techniques which can be used to optimize the lighting for synthetic images. These controls are based in part on observations of the lights used in the studio of a professional photographer. Controls include a light direction to aim a light at a particular area of an object, light concentration to simulate spotlights or floodlights, and flaps or cones to restrict the path of a light. Another control relates to the color of the light source and its effect on the perceived color of specular highlights. An object color can be blended with a color for the highlights to simulate different materials, paints, or lighting conditions. This can be accomplished dynamically while the image is displayed, using the video lookup table to approximate the specular color shift
Ray tracing algebraic surfaces
Authors: Hanrahan Pat
Published: November 2005

Many interesting surfaces can be written as polynomial functions of the spatial coordinates, often of low degree. We present a method based on a ray casting algorithm, extended to work in more than three dimensions, to produce pictures of these surfaces. The method uses a symbolic algebra system to automatically derive the equation of intersection between the ray and the surface and then solves this equation using an exact polynomial root finding algorithm.

Included are illustrations of the cusp catastrophe surface, and two unusually shaped quartic surfaces, Kummer's quadruple and Steiner's surface.