bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-thread input
Authors: Tanner P P
Published: November 2005

Implementors of interactive computer workstations have tended to shy away from making several devices simultaneously available to a user of their systems. The principal reason for this reluctance has been the difficulty faced by an application program in analyzing the several streams of input that such a configuration would present. Recently systems have been developed that support such multi-thread input. This paper discusses the requirements of multi-thread input and gives examples of how the requirements are being met by the experimental systems.
VisFiles
Authors: Elvins T. Todd
Published: November 2005

This is the first in a series of columns on the subject of data visualization. I'm excited to have this opportunity because it will give me an excuse to finally learn about some subjects that I've wanted to learn about but never gave myself the time. Gordon Cameron,
Computer Graphics
Editor, has given me some latitude on topics so future visualization columns will deal with color selection, data visualization systems and APIs, data visualization research, information visualization, user interface issues, tips and hints, etc. If you have comments on this column or suggestions for future columns, please send me email
(todd@acm.org).
In this issue I will give an overview of some familiar, and some probably unfamiliar, time-series data presentation techniques. Time-series data visualization is becoming an increasingly important topic as data archives grow exponentially and computing becomes ubiquitous. Some researchers claim that time-series data can be imaged using techniques similar to those applied to spatial data (since time is most often linear), and some claim that temporal data is a much different beast. For example, temporal data can have multiple strands and events, features not present in spatial data. There are also many interesting unsolved problems and data handling issues associated with temporal data:• Boolean and other mathematical operations• Data storage and temporal databases• Data query and retrieval• Data generalization (handling data at vastly different resolutions)• Data models and representation• Data presentationI have lately been working on designing a user interface for a simple geographic information system capable of manipulating and compositing time-series geo-referenced data. This project started me thinking about the different ways of visually representing temporal data. Without going into much detail on any one method, following are all the methods I could find within arms length in my office. Most of these methods allow the scientist or visualizer to present the time-series in a single image, while the final method uses an animation technique. Good techniques for visually presenting time-series data will:• Reveal spatial and temporal relationships• Uncover patterns• Show variability
The end of the CRT?
Authors: Myers Bob
Published: November 2005

Several technologies are becoming serious challengers to the time-honored cathode ray tube (CRT) as the display of choice for desktop use. This shift alone will have an impact on graphics hardware and software, but there are potentially greater changes on the horizon as these displays move off the desktop. This article examines the transition away from the CRT display, the changes this transition will demand from the rest of the computer system and what might be enabled by these new technologies and interfaces.
The ImmersaDesk and Infinity Wall projection-based virtual reality displays
Authors: Czernuszenko Marek , Pape Dave , Sandin Daniel , DeFanti Tom , Dawe Gregory L. , Brown Maxine D.
Published: November 2005

Virtual reality (VR) can be defined as interactive computer graphics that provides viewer-centered perspective, large field of view and stereo. Head-mounted displays (HMDs) and BOOMs™ achieve these features with small display screens which move with the viewer, close to the viewer's eyes. Projection-based displays [3, 7], supply these characteristics by placing large, fixed screens more distant from the viewer. The Electronic Visualization Laboratory (EVL) of the University of Illinois at Chicago has specialized in projection-based VR systems. EVL's projection-based VR display, the CAVE™ [2], premiered at the SIGGRAPH 92 conference.In this article we present two new, CAVE-derived, projection-based VR displays developed at EVL: the ImmersaDesk™ and the Infinity Wall™, a VR version of the PowerWall [9]. We describe the different requirements which led to their design, and compare these systems to other VR devices.
Health issues with virtual reality displays
Authors: Wann John P. , Mon-Williams Mark
Published: November 2005

During the late 1980s and early 1990s virtual reality (VR) technology enjoyed a prolonged honeymoon with the international media who presented a glossy futuristic image of the technology. It was inevitable that the media would eventually tire of this image and look for new journalistic angles, such as the negative effects of VR. Some speculation then ensued about the negative social consequences of VR in the public domain ("Social autism" and "The end of civilisation as we know it…" --- Stone, 1992, BBC Horizon), although these speculations now appear unfounded.The first direct assertion, in the international media, that there might be visual safety issues with VR technology, came from the reporting of findings from Mon-Williams, Wann and Rushton in 1993 [5]. Since then a steady trickle of media features have strongly hinted at virtual problems that may arise (e.g.
Business Week,
July 10, 1995;
New Scientist,
Jan 27, 1996), each being followed by accusations of "scare-mongering" from some sectors of the VR community. Our research findings have fueled some of the negative reports, and our position has angered some VR protagonists. Also, like other research groups in this field, we are often approached by journalists in pursuit of a sensationalist story.Hence we think it is timely to examine what we know about the effects of virtual reality displays; what we don't know about virtual reality displays; and what research should be undertaken to resolve the unknown issues.
A personal job-seeking odyssey
Authors: Collier Nancy
Published: November 2005

Imagine a world in which the oranges that looked so beautiful an hour ago in the market have a completely different color when you get them out of the bag at home. Imagine, when you approach a traffic light, you cannot tell what color the light is. Imagine the colors of traffic lights changing from one block to the next one. Could you?If you can't, just go to your computer and launch your World Wide Web browser. Viewing a color document on the Web, you cannot be sure what the colors will be. Some of it has been deliberate; so that people with different viewing capabilities can still view documents. That is why, under most circumstances, the color of the background, text and hyperlinks are all left to the choice of the client (browser) side.However, the World Wide Web has become a major source of information. Not only does it provide a wealth of information for you to consume, but it also gives you the opportunity to be an information producer --- a publisher.This, in turn, gives you the opportunity to violate every known recommendation for effective color usage! Indeed, a large majority of information producers on the Web either have not bothered to study such recommendations, or have decided to deliberately ignore them.Color on the Web has experienced the same neglect as in other applications of visual computing such as computer graphics, imaging and visualization. In all these cases, color was ignored or neglected for a long period of time before interest mounted.A case in point is the default color most Web browsers assign to hyperlinks: blue. As is well known, our visual system has the lowest sensitivity to blue, making it the worst color for small samples, such as text and line graphics.There are many other examples of sites on the Web that burden the viewer with text in colors that are barely readable, with insufficient contrast between foreground and background, with annoying color and texture combinations and more.As the Web is becoming more and more a preferred choice of publishing --- either exclusively, or in conjunction with traditional publishing channels --- the demand for higher-quality graphics, imaging, and thus color, will increase. It will not be long before publishers --- and, remember, on the Web
anybody
can be a publisher --- seek to publish high-quality graphics, just like the glossy stuff you see in magazines. To date, there isn't enough color capability in standard Web technology to support this goal.This article briefly explores color issues on the World Wide Web. We summarize the main color capabilities that are available to us on the Web today; the summary is as short as the capabilities to date.We anticipate that, as with other visual computing applications, interest will eventually arise in using and supporting color in a more complete and effective way. We thus attempt to outline what we consider to be the needs that lie ahead to obtain the improved color support needed.
Money
Authors: Wolfe R. J.
Published: November 2005

This article marks the beginning of a new column devoted to items of interest and concern to educators at all age levels. It addresses issues for those who teach computer graphics, as well as for those who use computer graphics to teach. This first column focuses on funding and how to obtain technology for the classroom.
The history of computer graphics standards development
Authors: Carson Steve , van Dam Andries , Puk Dick , Henderson Lofton R.
Published: November 2005

In keeping with the retrospective theme of this issue of
Computer Graphics,
Standards Pipeline takes a long look back at the history of the development of formal standards for computer graphics. As is fitting for a retrospective, there is a focus on where we have succeeded
and
where we have failed.Three guest authors contributed to this column. First, Andy van Dam takes us back to the early beginnings of standards for computer graphics and the forces that led to the first attempts at standards. Andy ends by describing the beginnings of the PHIGS and PHIGS+ standards efforts. Our second contributor, Richard F. Puk, who was the editor of the ISO PHIGS standard, describes its development in more detail, ending with its successes and its failures and a vision for the future. Our final contributor, Lofton Henderson brings us up to date on the development of the Computer Graphics Metafile and its amendments.
Computer graphics in Singapore
Authors: Chesnais Alain , Encarnação Jose , Seah H. , Lee Y. T.
Published: November 2005

This issue, we travel to Singapore for an update of this country's computer graphics activities.
SIGGRAPH VRML 3D Ph.D Conetree
Authors: Badler Norman I. , Webster Roger W.
Published: November 2005

This paper describes the work-in-progress of a VRML 3D conetree to visualize Ph.D. graduates and their Ph.D. thesis advisors in the field of computer graphics. As part of the SIGGRAPH history project chaired by Carl Machover, this VRML 3D conetree debuts publicly at the 25th conference celebration at SIGGRAPH 98, July 1998, in Orlando, FL. This conetree allows a VRML-enabled browser to visualize Ph.D. contributors to the field of computer graphics and to trace their influences and academic progeny. The database developed may seed further studies of the field's contributors. The initial phase of this project (using Ph.D advisors/graduates) provides a hierarchical (if arbitrary) view of part of SIGGRAPH's academic structure.
Introduction to collaborative visualization
Authors: Johnson Greg , Elvins T. Todd
Published: November 2005

To gain additional perspectives and expertise on data and information imaging topics, I will periodically solicit articles from researchers in the visualization community. Greg Johnson has graciously contributed this month's introduction to collaborative visualization. The subject is one that I feel is of growing importance and interest. Greg and I are interested in your views on this emerging technology and welcome your email.
Public policy issues featured at numerous conferences
Authors: Ellis Bob
Published: November 2005

This column again covers several items: a final update on ACM's Policy 98 conference and presentations I made at a Visualization 97 workshop and a Computers, Freedom and Privacy 98 birds-of-a-feather (BOF) meeting.
Professional chapters annual report
Authors: Lang Scott , Cleary Collen
Published: November 2005

Every year, each Director on the SIGGRAPH Executive Committee compiles an annual report for the annual SIGGRAPH organization report. To keep the overall report from becoming a book, the SIGGRAPH Chair must pick highlights from each area. This issue's
Computer Graphics
column contains my full annual report as presented to the SIGGRAPH Executive Committee. I hope that it helps to give you a better understanding of the structure of the Professional Chapters Committee, the events we sponsor at the annual conference and what the chapters do over the course of a typical year. Please keep in mind that this report is for the 1997-98 year so some information dates back to SIGGRAPH 97. As always, if you have any questions or comments, you can email me at
lang@siggraph.org.
Sketching in 3D
Authors: Zeleznik Robert
Published: November 2005

Of the numerous changes to the implements for creating 2D images and 3D models, one of the most radical has been the recent adoption of WIMP interfaces. Ironically, there is good reason to believe that WIMP interaction for 3D modeling is actually inferior to the real-world interfaces (pencils, large sheets of paper, clay, paint palettes) that it supplants. In fact, WIMP interaction's principal benefit is its straightforward integration with computer 3D model representations which have many advantages including ease of transformation, archival, replication and distribution.Instead of interpreting user compliance as an affirmation of WIMP interaction, we explore the dichotomy of how easy it is to depict a 3D object with just a pencil and paper, and how hard it is to model the same object using a multithousand dollar workstation. Our challenge is to blend the essence of pencil sketching interfaces with the power of computer model representations.This paper presents an overview of ongoing research in "sketch-like" 3D modeling user interfaces. The objective of this research is to design interfaces that match human ergonomics, exploit prelearned skills, foster new skills and support the transition from novice to skilled expert. Thus pencil sketching is an interaction ideal, supporting users ranging from children to adults, and from doodlers to artists. Perhaps the best testament to the effectiveness of the pencil and paper interface is that very few people even consider it a user interface.
Designing special-purpose input devices
Authors: Paley W. Bradford
Published: November 2005

For an increasing number of applications, we may be reaching the point of diminishing returns with general purpose computer input devices, such as the keyboard and mouse. At Digital Image Design Incorporated (DID) we've created special purpose input devices to perform tasks that are commonly addressed with software and general purpose devices alone. These more specific devices have led to significant advantages in accomplishing the tasks, and we've developed an approach to designing these devices that I hope will help others in doing similar work.When someone says "Build us a system to speed up computer character animation," the typical solution is purely software. This is not necessarily optimal or even cost effective, and the only way to determine that is to consider developing a hardware device during the initial project exploration. Let's go through the process of designing a special purpose device together. Real-world details are critical to this process, so we'll do it in the problem domain of animation, where DID and others have previously developed special purpose input devices. I'll generalize where appropriate.
Put that where? voice and gesture at the graphics interface
Authors: Billinghurst Mark
Published: November 2005

A person stands in front of a large projection screen on which is shown a checked floor. They say, "Make a table," and a wooden table appears in the middle of the floor."On the table, place a vase," they gesture using a fist relative to palm of their other hand to show the relative location of the vase on the table. A vase appears at the correct location."Next to the table place a chair." A chair appears to the right of the table."Rotate it like this," while rotating their hand causes the chair to turn towards the table."View the scene from this direction," they say while pointing one hand towards the palm of the other. The scene rotates to match their hand orientation.
In a matter of moments, a simple scene has been created using natural speech and gesture. The interface of the future? Not at all; Koons, Thorisson and Bolt demonstrated this work in 1992 [23]. Although research such as this has shown the value of combining speech and gesture at the interface, most computer graphics are still being developed with tools no more intuitive than a mouse and keyboard. This need not be the case. Current speech and gesture technologies make multimodal interfaces with combined voice and gesture input easily achievable. There are several commercial versions of continuous dictation software currently available, while tablets and pens are widely supported in graphics applications. However, having this capability doesn't mean that voice and gesture should be added to every modeling package in a haphazard manner. There are numerous issues that must be addressed in order to develop an intuitive interface that uses the strengths of both input modalities.In this article we describe motivations for adding voice and gesture to graphical applications, review previous work showing different ways these modalities may be used and outline some general interface guidelines. Finally, we give an overview of promising areas for future research. Our motivation for writing this is to spur developers to build compelling interfaces that will make speech and gesture as common on the desktop as the keyboard and mouse.
HMDs, caves & chameleon
Authors: Buxton Bill , Fitzmaurice George W.
Published: November 2005

There are a various approaches to implementing virtual reality (VR) systems. The head mounted display (HMD) and Cave approaches are two of the best known. In this paper, we discuss such approaches from the perspective of the types of interaction that they afford. Our analysis looks at interaction from three perspectives: solo interaction, collaborative interaction in the same physical space and remote collaboration. From this analysis emerges a basic taxonomy that is intended to help systems designers make choices that better match their implementation with the needs of their application and users.
The hemi-cube
Authors: Cohen Michael F. , Greenberg Donald P.
Published: November 2005

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 indepedent 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.
Compositing 3-D rendered images
Authors: Duff Tom
Published: November 2005

The complexity of anti-aliased 3-D rendering systems can be controlled by using a tool-building approach like that of the UNIX™ text-processing tools. Such an approach requires a simple picture representation amenable to anti-aliasing that all rendering programs can produce, a compositing algorithm for that representation and a command language to piece together scenes. This paper advocates a representation that combines Porter and Duff's compositing algebra with a Z-buffer to provide simple anti-aliased 3-D compositing.
Statistically optimized sampling for distributed ray tracing
Authors: Lee Mark E. , Redner Richard A. , Uselton Samuel P.
Published: November 2005

Cook, Porter, and Carpenter coined the phrase "distributed ray tracing" to describe a technique for using each ray of a super-sampled ray tracing procedure as a sample in several dimensions to achieve effects such as penumbras and motion blur in addition to spatial anti-aliasing. The shade to be displayed at a pixel is a weighted integral of the image function. The purpose of using many rays per pixel is to estimate the value of this integral. In this work, a relationship between the number of sample rays and the quality of the estimate of this integral is derived. Furthermore, the number of rays required does not depend on the dimensionality of the space being sampled, but only on the variance of the multi-dimensional image function. The algorithm has been optimized through the use of statistical testing and stratified sampling.
A two-and-a-half-D motion-blur algorithm
Authors: Max Nelson L. , Lerner Douglas M.
Published: November 2005

Algorithms are presented for raster and vector motion blur, which produce images and masks suitable for combination by the 21/2-D compositing process. The raster algorithm is based on a "skew, blur, unskew" scheme, using a very efficient one-dimensional blurring algorithm. The vector algorithm extends the ideas of anti-aliased scan conversion to motion blur.
Fast spheres, shadows, textures, transparencies, and imgage enhancements in pixel-planes
Authors: Fuchs Henry , Goldfeather Jack , Hultquist Jeff P. , Spach Susan , Austin John D. , Brooks Frederick P. , Eyles John G. , Poulton John
Published: November 2005

Pixel-planes is a logic-enhanced memory system for raster graphics and imaging. Although each pixel-memory is enhanced with a one-bit ALU, the system's real power comes from a tree of one-bit adders that can evaluate linear expressions
Ax+By+C
for every pixel
(x,y)
simultaneously, as fast as the ALUs and the memory
circuits
can accept the results. We and others have begun to develop a variety of algorithms that exploit this fast linear expression evaluation capability. In this paper we report some of those results. Illustrated in this paper is a sample image from a small working prototype of the Pixel-planes hardware and a variety of images from simulations of a full-scale system. Timing estimates indicate that 30,000 smooth shaded triangles can be generated per second, or 21,000 smooth-shaded and shadowed triangles can be generated per second, or over 25,000 shaded spheres can be generated per second. Image-enhancement by adaptive histogram equalization can be performed within 4 seconds on a 512x512 image.
Bintrees, CSG trees, and time
Authors: Samet Hanan , Tamminen Markku
Published: November 2005

A discussion is presented of the relationship between two solid representation schemes: constructive solid geometry (CSG trees) and recursive spatial subdivision exemplified by the bintree, a generalization of the quadtree and octree. Detailed algorithms are developed and analyzed for evaluating CSG trees by bintree conversion, i.e., by determining explicitly which parts of space are solid and which empty. These techniques enable the addition of the time dimension and motion to the approximate analysis of CSG trees in a simple manner to solve problems such as dynamic interference detection. For "well-behaved" CSG trees, the execution time of the conversion algorithm is directly related to the spatial complexity of the object represented by the CSG tree (i.e., asymptotically it is proportional to the number of bintree nodes as the resolution increases). The set of well-behaved CSG trees includes all trees that define multidimensional polyhedra in a manner that does not give rise to tangential intersections at CSG tree nodes.
A unified approach to interference problems using a triangle processor
Authors: Yamaguchi Fujio
Published: November 2005

Triangulation is an efficient way to simplify and unify interference problems, such as hidden line and surface elimination and Boolean shape operations in solid modeling. Almost all of the processing relevant to a triangle can be performed by computing some 4 x 4 determinants. The author proposes a hardware processor (TRIANGLE PROCESSOR) that quickly intersects a triangle with a point, a line segment, or another triangle. Various applications of the TRIANGLE PROCESSOR are explained in this paper, including applications to face and volume triangulations.The author stresses that the triangulation approach and the TRIANGLE PROCESSOR simplify, speed up and unify various types of processing relating to interference.
Blend surfaces for set theoretic volume modelling systems
Authors: Middleditch Alan E. , Sears Kenneth H.
Published: November 2005

Most volume modelling systems are very limited in the complexity of the surfaces which they support. This is satisfactory for basic models of most mechanical components, since the functional surfaces are not usually complex. However, there are often blends between simple base surfaces. This paper presents a technique appropriate for blend definition and profile control. A discussion of blend conics is used to develop analogous surfaces for use in typical volume modelling systems. These surfaces are then used to set theoretically define bounded volumes for fillets and chamfers. Empirical results show that the method described suits many engineering applications.
On ray tracing parametric surfaces
Authors: Toth Daniel L.
Published: November 2005

A new method for ray tracing parametric surfaces is presented. The new algorithm solves the ray surface intersection directly using multivariate Newton iteration. This provides enough generality to render surfaces which could not be ray traced using existing methods. To overcome the problem of finding a starting point for the Newton algorithm, techniques from Interval Analysis are employed. The results are presented in terms of solving a general nonlinear system of equations f(x)= 0, and thus can be extended to a large class of problems which arise in computer graphics.
Juno, a constraint-based graphics system
Authors: Nelson Greg
Published: November 2005

Juno is a system that harmoniously integrates a language for describing pictures with a what-you-see-is-what-you-get image editor. Two of Juno's novelties are that geometric constraints are used to specify locations, and that the text of a Juno program is modified in response to the interactive editing of the displayed image that the program produces.
Animating rotation with quaternion curves
Authors: Shoemake Ken
Published: November 2005

Solid bodies roll and tumble through space. In computer animation, so do cameras. The rotations of these objects are best described using a four coordinate system, quaternions, as is shown in this paper. Of all quaternions, those on the unit sphere are most suitable for animation, but the question of how to construct curves on spheres has not been much explored. This paper gives one answer by presenting a new kind of spline curve, created on a sphere, suitable for smoothly in-betweening (i.e. interpolating) sequences of arbitrary rotations. Both theory and experiment show that the motion generated is smooth and natural, without quirks found in earlier methods.
Computational modeling for the computer animation of legged figures
Authors: Girard Michael , Maciejewski A. A.
Published: November 2005

Modeling techniques for animating legged figures are described which are used in the PODA animation system. PODA utilizes pseudoinverse control in order to solve the problems associated with manipulating kinematically redundant limbs. PODA builds on this capability to synthesize a kinematic model of legged locomotion which allows animators to control the complex relationships between the motion of the body of a figure and the coordination of its legs. Finally, PODA provides for the integration of a simple model of legged locomotion dynamics which insures that the accelerations of a figure's body are synchronized with the timing of the forces applied by its legs.
Solid texturing of complex surfaces
Authors: Peachey Darwyn R.
Published: November 2005

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 surface 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.
Approximate and probabilistic algorithms for shading and rendering structured particle systems
Authors: Reeves William T. , Blau Ricki
Published: November 2005

Detail enhances the visual richness and realism of computer-generated images. Our stochastic modelling approach, called
particle systems
, builds complex pictures from sets of simple, volume-filling primitives. For example, structured particle systems have been used to generate trees and a grass-covered forest floor. Particle systems can produce so much irregular, three-dimensional detail that exact shading and visible surface calculations become infeasible. We describe approximate and probabilistic algorithms for shading and the visible surface problem. Because particle systems algorithms generate richly-detailed images, it is hard to detect any deviation from an exact rendering. Recent work in stochastic modelling also enables us to model complex motions with random variation, such as a field of grass blowing in the breeze. We analyze the performance of our current algorithms to understand the costs of our stochastic modelling approach.
"Last-mile" bandwidth recap and committee survey activity
Authors: Ellis Bob , Losch Myles , Nelson David , Reinhart Laurie
Published: November 2005

For people interested in graphics and graphical user interfaces, the greatest shortcoming of the Internet is bandwidth, particularly lines to consumer premises. Although most computing professionals have access to high bandwidth connections, most consumers do not. Consumer access to computing and the Internet is probably the most significant development in computing since 1980. This market now drives computing, and hence computer graphics, so it behooves all of us to understand the "last-mile" issues, both technical and political.I have enlisted the assistance of SIGGRAPH Public Policy Committee member Myles Losch to co-author this report with me, I'd also like to give advance notice of the forthcoming Public Policy BOF, which will be held at the SIGGRAPH 99 conference in Los Angeles. This will feature Myles, as well as perhaps an outside speaker and myself speaking on this topic. At time of writing, the BOF has yet to be scheduled, but traditionally it has been held early afternoon on the Thursday of the conference.Following up on our announcement of the first on-line public policy survey in the last issue, committee members Laurie Reinhart and David Nelson present the initial results. Don't forget that sometime in April the second survey replaced the first one. The second survey looks at computer graphics developments that will be important in research and commercial areas and is our contribution to the forward-looking events at the SIGGRAPH 30th year celebration at SIGGRAPH 99.
BIIF, VRML and CGM
Authors: Kuzma Bernadette , Carson George S. , Puk Richard F. , Gebhardt John
Published: November 2005

This edition of the Standards Pipeline consists of three articles that provide an in-depth look at applications of three important international standards. In the first article, Bernadette Kuzma of SEMCOR, Inc. describes the Basic Image Interchange Format (BIIF) formally known as ISO/IEC 12087-5:1998. While BIIF originated in the defense community, it is beginning to find wider applications in areas ranging from electronic libraries to medical imaging. In the second article, Richard F. Puk of Intelligraphics describes the current status and future prospects for the Virtual Reality Modeling Language (VRML) formally known as ISO/IEC 14772-1. In the final article, Lofton Henderson of Inso Corporation and John Gebhardt of InterCAP Graphics Systems, Inc. describe the work of the CGM Open Consortium and in particular the WebCGM profile.
Large networks present visualization challenges
Authors: Abello James , Koutsofios Eleftherios , Gansner Emden R. , North Stephen C.
Published: November 2005

Large networks pose an increasingly important visualization problem. So for the first guest column during my tenure as VisFiles columnist, I asked Stephen North to contribute an article about the great work at AT&T Labs - Research.
A look at 3D graphics industry
Authors: Latta John
Published: November 2005

In this month's Real-time Interactive Graphics column we take a look at the 3D graphics industry through the unique perspective of long-time industry analyst and observer, John Latta. Latta's company, 4th Wave, Inc. publishes a widely read newsletter on 3D and digital media called the Wave Report
(http://www.wave-report.com/).
A Reminder
We are very interested in hearing from our readers. In particular, if you are involved in a new (real-time, interactive) application, or have a related topic that you think might be interesting to share with the SIGGRAPH membership through our column, please let us know. Also, if you have feedback to offer on current or past columns, we would be more than glad to hear it!
Computer graphics in Scandanavia
Authors: Chesnais Alain , Encarnação Jose
Published: November 2005

Nowadays, computer graphics is a commonly utilized tool deployed both in universities and industry. A short overview like this can't hope to cover all activities, but I've attempted to give some examples from the field in Scandinavia.Overviews of computer graphics activity in Scandinavia have previously been published in
Computer Graphics,
30(2) May 1996 (research) and 30(3) August 1996 (education). In addition, the journal
Computers and Graphics
had a special issue on computer graphics in Scandinavia in 1995. In this overview we won't duplicate the material from the previous overviews, but rather attempt to give some additional examples of computer graphics research work.
Focus on “last mile” bandwidth continues
Authors: Losch Myles
Published: November 2005

As mentioned in the last column (
Computer Graphics
33(2) May 1999), committee member Myles Losch and I will present and discuss the "last-mile" bandwidth issue at the annual Public Policy SIG meeting at SIGGRAPH 99 in Los Angeles. The meeting is Thursday, August 12 from 2:00 to 3:00 p.m. in room 507 of the Los Angeles Convention Center. We will be reviewing the material contained in the May 1999 column and answering questions on technical topics and policy issues. All Internet users, particularly computer graphics users, will be interested in this topic.Each year the Computers, Freedom and Privacy (CFP) conference brings together technical people and policy makers to discuss issues resulting from the availability and use of computing technology. This year, Myles and I (well, mostly Myles) organized a session on "Last-Mile" Broadband Access with speakers representing all the major players. Below, Myles summarizes this session as well as presents highlights from the CFP 99 conference.
Presenting visual infomation responsibly
Authors: Gershon Nahum
Published: November 2005

"Seeing is believing""Seeing is not believing"
Are faithfulness and accuracy necessary?
Authors: Gershon Nahum
Published: November 2005

"We are approximate beings…Animals don't require precise measurements and high accuracy to function. Machines do."
Vision in film and special effects
Authors: Roble Doug
Published: November 2005

Computer vision techniques have become increasingly important in visual effects. When a digital artist inserts an effect into a live-action scene, the more information that they know about the scene, the better. In visual effects, we use vision techniques to calculate the location of the camera, construct a 3D model of the scene and follow objects as they move through the scene.Think back to the 1980s, before computer graphics in special effects really took hold. In most of the films of that era, it was very easy to spot the "effects shot" in a film. The give-away was the sudden halting of a previously dynamic, moving camera. This was done because inserting a special effect character or object into a scene with a moving camera was very difficult. The camera move used in filming the live action part of the scene must be exactly reproduced by the camera on the effects set when the model or puppet is filmed. To accomplish this, one of two techniques were employed: 1) mechanical devices were used to encode the motion of the camera and then the encoded information was used to control the motion of the camera on the effects set, or 2) an experienced motion control engineer matched the move by eye. Both of these techniques are terribly prone to error and were used only on high budget productions.In the 1990s with the advent of widespread computer generated effects and digital scanning of film, it became possible to apply computer vision techniques to extract information from the scene to aid the digital artist in blending an effect with the reality of the filmed image.
Computer vision for computer interaction
Authors: Freeman William T. , Beardsley Paul A. , Kage Hiroshi , Tanaka Ken-Ichi , Kyuma Kazuo , Weissman Craig D.
Published: November 2005

Figure 1 shows a vision of the future from the 1939 World's Fair. The human-machine interface that was envisioned is wonderful. Both machines are equipped with cameras; the woman interacts with the machine using an intuitive gesture. That degree of naturalness is a goal today for researchers designing human-machine interfaces.
Teaching computer graphics visual literacy to art and computer science students
Authors: Eber Dena , Wolfe Rosalee
Published: November 2005

Although it is a requisite skill for success in industry, visual literacy in graphics is intimidating to computer science and art students. Computer science majors are uneasy about using their eyes to examine images while art students may not have much background in the technical terminology. This column is the second in a two-part series that discusses an interdisciplinary teaching technique that overcomes these obstacles. Part one was published in
Computer Graphics
34(1) February 2000, pp. 24-26. With this approach students become more familiar with the limits and possibilities of the medium of computer graphics, learn how to analyze and talk about what visual images might mean and develop a deeper understanding of time constraints. In addition, they gain confidence with technological terminology and the idea of suggesting alternative algorithms to create a desired visual "look." As a result both computer science and art students become more able to communicate effectively about and with visual imagery.
A collaborative and interdisciplinary computer animation course
Authors: Ebert David S. , Bailey Dan
Published: November 2005

David Ebert and Dan Bailey have developed an innovative and supportive environment for art and computer science students to collaborate on large scale graphics projects. This is exciting because in many academic institutions, students from these two disciplines never have a chance to meet each other, much less work together. Ebert hails from the CSEE Department at the University of Maryland Baltimore County, and Bailey is a member of the Visual Arts Department at UMBC. In this article, they discuss their choice of topics, their pedagogy and an evaluation of what worked.
Spatial standardization
Authors: Carson George S.
Published: November 2005

This Standards Pipeline reports on recent work within the international standards community to coordinate standards efforts that deal with spatial information, and especially geo-spatial information. Two special meetings on this topic were recently held. The first meeting was at Sun Microsystems in Menlo Park, CA, February 14-16, 2000 and the second at ISO headquarters in Geneva, Switzerland on May 2-4, 2000.
Principles of traditional animation applied to 3D computer animation
Authors: Lasseter John
Published: November 2005

This paper describes the basic principles of traditional 2D hand drawn animation and their application to 3D computer animation. After describing how these principles evolved, the individual principles are detailed, addressing their meanings in 2D hand drawn animation and their application to 3D computer animation. This should demonstrate the importance of these principles to quality 3D computer animation.
Fast ray tracing by ray classification
Authors: Arvo James , Kirk David
Published: November 2005

We describe a new approach to ray tracing which drastically reduces the number of ray-object and ray-bounds intersection calculations by means of 5-dimensional space subdivision. Collections of rays originating from a common 3D rectangular volume and directed through a 2D solid angle are represented as hypercubes in 5-space. A 5D volume bounding the space of rays is dynamically subdivided into hypercubes, each linked to a set of objects which are candidates for intersection. Rays are classified into unique hypercubes and checked for intersection with the associated candidate object set. We compare several techniques for object extent testing, including boxes, spheres, plane-sets, and convex polyhedra. In addition, we examine optimizations made possible by the directional nature of the algorithm, such as sorting, caching and backface culling. Results indicate that this algorithm significantly outperforms previous ray tracing techniques, especially for comples environments.
FRAMES: Software tools for modeling, rendering and animation of 3D scenes
Authors: Potmesil Michael , Hoffert Eric M.
Published: November 2005

FRAMES is a set of flexible software tools, developed for the UNIX programming environment, that can be used to generate images and animation of 3D scenes. In FRAMES, each stage of the image-rendering pipeline is assigned to a UNIX System filter. The following is a typical FRAMES pipe sequence where each filter performs a task implied by its name:cat scene.frm|euclid|mover|shade|camera|abufFRAMES was designed to be easy to use, to permit flexible experimentation with new ideas in image rendering and geometric modeling, to allow distribution of different parts of the rendering pipeline to different processors, and to specify images in a common format for display on a variety of devices.The user communicates with FRAMES via a command language. This language is extended whenever a software developer needs to incorporate a new idea into the system by adding new commands. Data flowing through the pipeline is modified by a collection of filter programs and passed through the pipe in text or binary format.The modular and pipe-based nature of FRAMES allows for multi/parallel processor implementations and device independence. FRAMES has generated images on a local-area network of minicomputers (each filter runs on a different processor) and on a 64-processor hypercube machine (one filter runs on 64 processors). Applications of FRAMES have ranged from reconstruction of neurons from serial sections to rendering of antialiased octree objects with subpixel detail.
Ray tracing complex models containing surface tessellations
Authors: Snyder John M. , Barr Alan H.
Published: November 2005

An approach to ray tracing complex models containing mathematically defined surfaces is presented. Parametric and implicit surfaces, and boolean combinations of these, are first tessellated into triangles. The resulting triangles from many such surfaces are organized in a hierachy of lists and 3D grids, allowing efficient calculation of ray/model intersections.The technique has been used to ray trace models containing billions of traiangles and surfaces never before ray traced. The organizing scheme developed is also independently useful for efficiently ray tracing any complex model, whether or not it contains surface tessellations.
Set operations on polyhedra using binary space partitioning trees
Authors: Thibault William C. , Naylor Bruce F.
Published: November 2005

We introduce a new representation for polyhedra by showing how Binary Space Partitioning Trees (BSP trees) can be used to represent regular sets. We then show how they may be used in evaluating set operations on polyhedra. The BSP tree is a binary tree representing a recursive partitioning of d-space by (sub-)hyperplanes, for any dimension d. Their previous application to computer graphics has been to organize an arbitrary set of polygons so that a fast solution to the visible surface problem could be obtained. We retain this property (in 3D) and show how BSP trees can also provide an exact representation of arbitrary polyhedra of any dimension. Conversion from a boundary representation (B-reps) of polyhedra to a BSP tree representation is described. This technique leads to a new method for evaluating arbitrary set theoretic (boolean) expressions on B-reps, represented as a CSG tree, producing a BSP tree as the result. Results from our language-driven implmentation of this CSG evaluator are discussed. Finally, we show how to modify a BSP tree to represent the result of a set operation between the BSP tree and a B-rep. We describe the embodiment of this approach in an interactive 3D object design program that allows incremental modification of an object with a tool. Placement of the tool, selection of views, and performance of the set operation are all performed at interactive speeds for modestly complex objects.
Marching cubes: A high resolution 3D surface construction algorithm
Authors: Lorensen William E. , Cline Harvey E.
Published: November 2005

We present a new algorithm, called
marching cubes
, that creates triangle models of constant density surfaces from 3D medical data. Using a divide-and-conquer approach to generate inter-slice connectivity, we create a case table that defines triangle topology. The algorithm processes the 3D medical data in scan-line order and calculates triangle vertices using linear interpolation. We find the gradient of the original data, normalize it, and use it as a basis for shading the models. The detail in images produced from the generated surface models is the result of maintaining the inter-slice connectivity, surface data, and gradient information present in the original 3D data. Results from computed tomography (CT), magnetic resonance (MR), and single-photon emission computed tomography (SPECT) illustrate the quality and functionality of
marching cubes
. We also discuss improvements that decrease processing time and add solid modeling capabilities.