bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predetermining visibility priority in 3-D scenes (Preliminary Report)
Authors: Fuchs Henry , Kedem Zvi M. , Naylor Bruce 
Published: November 2005

The principal calculation performed by all visible surface algorithms is the determination of the visible polygon at each pixel in the image. Of the many possible speedups and efficiencies found for this problem, only one published algorithm (developed almost a decade ago by a group at General Electric) took advantage of an observation that many visibility calculations could be performed without knowledge of the eventual viewing position and orientation—
once for all possible images
. The method is based on a “potential obscuration” relation between polygons in the simulated environment. Unfortunately, the method worked only for certain objects; unmanagable objects had to be manually (and expertly!) subdivided into managable pieces.

Described in this paper is a solution to this problem which allows substantial a priori visibility determination for all possible objects without any manual intervention. The method also identifies the ( hopefully, few) visibility calculations which remain to be performed after the viewing position is specified. Also diescussed is the development of still stronger solutions which could further reduce the number of these visibility calculations remaining at image generation time.
The reduction in overall processing and memory requirements enabled by this approach may be quite significant, especially for those applications (e.g., 3-D simulation, animation, interactive design) in which numerous visible surface images are generated from a relatively stable data base.
A colour display unit for a 21-channel EEG-monitor
Authors: Paternoster R. H. , Bousse L. J. , Steenhaut O. L. 
Published: November 2005

A system for the simultaneous display of several functions of one or two variables has been developed. One-variable functions are represented by their graphs, while two-variable functions are displayed by means of contour maps, with a light intensity proportional to the displayed value. By assigning a fixed colour to each contour map, it is possible to superimpose different maps without losing charity. The display unit is connected with a microprocessor system, which allows the real-time calculation and display of time-changing functions.
The primary application of the system is the representation of the distribution of the spectral contents of EEG (electro-encephalographic) signals on the surface of the head.
A network graphical conferencing system
Authors: O'Brien Michael T. 
Published: November 2005

A network-oriented color graphical conferencing system is being built by the Information Sciences Dept. of the Rand Corporation. This system is designed to allow several people to confer simultaneously over a network. Users share a common display, which is divided into sections: an individual section (or “window”) for each user, and a common graphical “blackboard” window where the users may take turns sketching out and modifying a graphical display in full color. The display uses bit-map color raster-scan technology.
Each user's private window is identified with that user's name and location. Text typed by a user appears in his window as he types it. Several users may be typing text simultaneously. A special symbol appears in the window of a user who is sketching to indicate who is drawing the picture.
Several conferences may be going on at the same time; users may request a menu page showing who is participating in which conferences. Conferences may be “locked” to prevent others from joining.
The system makes use of other Rand-developed utilities for the design and display of arbitrary characters, as well as Rand's Virtual Terminal UNIX (TM) operating system.
Generating smooth 2-D monocolor line drawings on video displays
Authors: Barros Jose , Fuchs Henry 
Published: November 2005

One of the major drawbacks of video display systems for line drawing applications has been the poor image quality they usually produce—“jaggy”, “staircased” line edges, moire patterns in regions of closely spaced lines, even, with some systems, lines disappearing (“falling in”) between pixels. Correcting these effects, with appropriate area-sampling techniques, has generally been too computationally expensive to adopt.
A new algorithm is presented which generates precise, smooth images of line drawings and solid polygonal-shaped objects on multi-grey-level pixel-mapped video systems. The method is based on an analysis of boundary conditions at each pixel affected by one or more lines. With this method a number of previously needed steps can be quickly eliminated. The commonality of boundary conditions between adjacent pixels and the coherence of such conditions in a raster-scan ordering of such pixels allows efficient generation of these boundary conditions. A recursive subdivision approach allows handling of arbitrarily complex cases by a simple boundary-analyzing technique. Compared with current line-drawing systems, a video system with this algorithm would also display an improved image with respect to certain common visual effects—e.g., distance modulation of line intensity (which may be desirable), artificial small bright clusters of detail (which is undesirable).
Since the software interface to the algorithm may be handled through already-standard graphical subroutines, adoption of the algorithm may be accomplished without burdening graphic system users or graphic system-utilizing software.
The theory, design, implementation and evaluation of a three-dimensional surface detection algorithm
Authors: Artzy Ehud , Frieder Gideon , Herman Gabor T. 
Published: November 2005

In many three-dimensional imaging applications the three-dimensional scene is represented by a three-dimensional array of volume elements, or voxels for short. A subset Q of the voxels is specified by some property. The objects in the scene are then defined as subsets of Q formed by voxels which are “connected” in some appropriate sense. It is often of interest to detect and display the surface of an object in the scene, specified say by one of the voxels in it.
In this paper, the problem of surface detection is translated into a problem of traversal of a directed graph, G. The nodes of G correspond to faces separating voxels in Q from voxels not in Q. It has been proven that connected subgraphs of G correspond to surfaces of connected components of Q (i.e., of objects in the scene). Further properties of the directed graph have been proven, which allow us to keep the number of marked nodes (needed to avoid loops in the graph traversal) to a small fraction of the total number of visited nodes.
This boundary detection algorithm has been implemented. We discuss the interaction between the underlying mathematical theory and the design of the working software. We illustrate the software on some clinical studies in which the input is computed tomographic (CT) data and the output is dynamically rotating three-dimensional displays of isolated organs. Even though the medical application leads to very large scale problems, our theory and design allows us to use our method routinely on the minicomputer of a CT scanner.
Polygon comparison using a graph representation
Authors: Weiler Kevin 
Published: November 2005

All of the information necessary to perform the polygon set operations (union, intersection, and difference) and therefore polygon clipping can be generated by a single application of a process called
polygon comparison.
This process accepts two or more input polygons and generates one or more polygons as output. These output polygons contain unique homogenous areas, each falling within the domain of one or more input polygons. Each output polygon is classified by the list of input polygons in which its area may be found. The union contour of all input is also generated, completing all of the information necessary to perform the polygon set operations.

This paper introduces a polygon comparison algorithm which features reduced complexity due to its use of a graph data representation. The paper briefly introduces some of the possible approaches to the general problem of polygon comparison including the polygon set and clipping problems. The new algorithm is then introduced and explained in detail.
The algorithm is sufficiently general to compare sets of concave polygons with holes. More than two polygons can be compared at one time; all information for future comparisons of subsets of the original input polygon sets is available from the results of the initial application of the process.
The algorithm represents polygons using a graph of the boundaries of the polygons. These graphs are imbedded in a two dimensional geometric space. The use of the graph representation simplifies the comparison process considerably by eliminating many special cases from explicit consideration.
Polygon operations like the ones described above are useful in a variety of application areas, especially those which deal with problems involving two dimensional or projected two dimensional geometric areas. Examples include VLSI circuit design, cartographic and demographic applications, and polygon clipping for graphic applications such as viewport clipping, hidden surface and line removal, detailing, and shadowing.
High-performance raster graphics for microcomputer systems
Authors: Bechtolsheim Andreas , Baskett Forest 
Published: November 2005

A frame buffer architecture is presented that reduces the overhead of frame buffer updating by three means. First, the bit-map memory is (x,y) addressable, whereby a string of pixels can be accessed in parallel. Second, the pixel-change operation is performed by hardware in a single read-modify-write cycle. Third, multiple objects in the frame buffer are addressable simultaneously by a set of address registers. The remaining task of generating (x,y) addresses and providing new data can be managed rapidly by current microprocessors or DMA-devices.
With a modest expenditure of hardware, this architecture eliminates all the bit-shifting, bit-masking, and bit-manipulation conventionally associated with frame buffer graphics, while retaining the full generality of user-programmable control. The particular implementation described allows raster manipulation at full bit-map memory bandwidth. It can paint a 16×16 pixel character into the frame buffer in 16 microseconds and can modify a 1024×1024 pixel raster in 64 milliseconds.
Simulation and expected performance analysis of multiple processor Z-buffer systems
Authors: Parke Frederic I. 
Published: November 2005

The results of expected performance analysis and simulation of three multiple processor Z-buffer architectures are presented. These architectures have been proposed as approaches to applying many processors, working in parallel, to the task of rapidly creating shaded raster images. These architectures are attractive since they offer potentially high performance, in terms of image update rate, at modest cost. All three approaches make use of multiple instances of identical processor modules.
The analyses and simulations indicate that substantial gain is possible by applying multiple processors to the task. But, as more and more processors are added, additional gains in performance become smaller and smaller. This result suggests optimal system sizes. The performance of these architectures depends on the processors used, the number of processors, and certain characteristics of the image environments. Each architecture has its own performance characteristics and limitations.
Trends in high performance graphic systems(Panel Session)
Authors: Cohen D. , Sproull Bob , Clark Jim , Parke Fred , Fuchs Henry 
Published: November 2005

Accompanying the rapid development of integrated circuit fabrication technology has been a parallel, but slower, development of IC design techniques and systems. Recent approaches to IC design enable individual designers to consider developing their own VLSI circuits. Such capability may open the door to a more varied set of system designs than could previously be considered in most design environments.
The panel members are all currently designing graphic systems oriented towards VLSI implementation. Each will give a short presentation describing one of their system designs. Following these presentations, three members of the previous session (Forest Baskett, Andreas Bechtolsheim, and Fred Parke) will discuss common issues, problems, and future prospects.
A prototype Spatial Data Management System
Authors: Herot Christopher F. , Carling Richard , Friedell Mark , Kramlich David 
Published: November 2005

Spatial Data Management is a technique for organizing and retrieving information by positioning it in a spatial framework. Data is accessed in a Spatial Data Management System (SDMS) via pictorial representations which are arranged in space and viewed through a computer graphics system. These pictures can be created by an interactive graphical editor, allowing an SDMS to serve as a personal repository of diagrams, text, and photographs. Pictograms can also be generated from data in a symbolic database management system, allowing SDMS to be used as an interface to large, shared databases.
A prototype SDMS has been constructed which employs a set of color, raster scan displays driven by a large minicomputer. The user can create and examine data surfaces which are larger than the display screen, traversing a surface and zooming in and out to control the level of detail displayed. The prototype system provides a uniform mechanism for accessing a wide variety of data types in a manner which does not require the use of a formal command or query language.
QUADRIL
Authors: Levin Joshua Zev 
Published: November 2005

Most man-made objects can be closely approximated by bodies whose surfaces are composed of portions of second-order (quadric) surfaces. These surfaces include elliptic, hyperbolic, and parabolic cylinders, as well as quadric cones, paraboloids, hyperboloids, ellipsoids, and pairs of planes. Simple planes (first-order surfaces) may be included as degenerate quadric surfaces.
Because these quadric-surface bodies are so useful for modelling man-made objects, it is important that any Computer-Aided Design (CAD) system be able to work with such bodies. The “QUADRIL” language described here was designed to accept descriptions of quadric-surface bodies in character-string form.
QUADRIL has a mixture of English-like and algebraic syntax. It may be used to specify quadric-surface bodies and then to display them on various media.
QUADRIL will accept descriptions of quadric-surface bodies either as “volumetric” combinations of basic bodies, or as boolean functions of bounding surfaces. English-like syntax is used for specifying what surfaces and basic bodies are used, while algebraic syntax is used to transform the canonical forms of the surfaces or bodies into the shape, position, and orientation that the user desires.
Volumetric combination of bodies involves the operations of union (+), intersection (*), and subtraction (-). Boolean specification of volumes is in terms of a boolean tree with the bounding surfaces as leaf nodes. The tree is expressed as a character string.
QUADRIL permits using user-created “STRUCTURES” as component bodies (“OBJECTS”) in greater STRUCTURES.
The display of the quadric-surface bodies may also be specified in QUADRIL. The user is considered fixed in space, while the body is transformed to give the desired view.
A structure from manipulation for text-graphic objects
Authors: Lakin Fred H. 
Published: November 2005

The general purpose graphics systems of the future will need a simple logic for visual objects—one structure underlying both text and graphics. As an experiment, perhaps the immediate handling of visual objects by the user can provide the starting point for developing that structure. This paper describes the PAM graphics system, in which
the structure of text-graphic objects arises directly out of manual manipulation.
The needs of manual manipulation determine the
text-graphic pattern
as the simplest organizing structure for images; PAM stands for
P
Attern
M
anipulating. The PAM system is designed for the agile manipulation of text-graphic patterns—first manually, and then, later, programmatically.

Starting from this strict 'front-in' viewpoint—where immediate manipulation (hand powered animation) was to be the primary application—a 'manipulative grammar' was evolved to give the user a simple yet powerful handle on text-graphic images. This grammar turned out to be a generalization of LISP syntax from textual symbolic expressions to text-graphic forms, structuring such forms as trees and then offering:
@@@@spatial GRABBING of objects into attention
@@@@tree guided attention shifters like FIRST, REST, NEXT, and UP
spatial & tree manipulations on any object in attention.

@@@@The resulting structures also offer surprising computational power (in a manner directly analogous to the way the basic list structures and functions of LISP give rise to the flexibility and power of a full blown LISP system, McCarthy and Talcott [1]), leading finally to
computing with text-graphic forms.
Consequently, a
semantic
function is added to supplement the basic manipulative grammar:

@@@@evaluation of object in attention, result displayed at the cursor. Evaluation supports facilities like naming (and thus saving) visual objects, programming, and creation of menus (patterns of evaluatable function objects).
An experimental version of the PAM system has been implemented in MACLISP at the Stanford Artificial Intelligence Lab.
Computer rendering of fractal curves and surfaces
Authors: Carpenter Loren C. 
Published: November 2005

Fractals are a class of highly irregular shapes that have myriad counterparts in the real world, such as islands, river networks, turbulence, and snowflakes. Classic fractals include Brownian paths, Cantor sets, and plane-filling curves. Nearly all fractal sets are of fractional dimension and all are nowhere differentiable.
Previously published procedures for calculating fractal curves employ shear displacement processes, modified Markov processes, and inverse Fourier transforms. They are either very expensive or very complex and do not easily generalize to surfaces. This paper presents a family of simple methods for generating and displaying a wide class of fractal curves and surfaces. In so doing, it introduces the concept of statistical subdivision in which a geometric entity is split into smaller entities while preserving certain statistical properties.
Stereographic displays of atmospheric model data
Authors: desJardins Mary , Hasler A. Frederick 
Published: November 2005

A system has been developed to display color stereographic time-lapsed sequences of outputs of three-dimensional atmospheric models. Contour lines and wind vectors derived from a model can be overlaid on a geostationary satellite image or displayed with map boundaries. The colors of these graphics can be changed interactively to highlight any desired feature or aid in interpreting relationships between parameters.
The viewing portion of the system consists of a raster scan image display terminal with split screen capability and a stereoscopic viewing hood.
The user of the system can observe model outputs in color and stereo as a function of time and in a manner which permits easy visualization and comparison.
The system permits a meteorologist to visualize atmospheric parameters in a three-dimensional representation and correlate these parameters with information derived from satellite observations. This capability can significantly increase the user's ability to interact with and understand complex meteorological relationships.
Optical printing in computer animation
Authors: Max Nelson , Blunden John 
Published: November 2005

The optical printer can be considered as an optical analog computer, which can perform geometric transformations and simple arithmetic operations on pictures very efficiently. The principles of operation of the printer are explained, and many of its applications to computer animation are listed and discussed briefly.
Two techniques are discussed in detail: the use of high contrast masks to suppress the bright spots where two lines of different colors cross, and the use of continuous tone masks and multiple exposures to create realistic transparency at low cost.
Interactive computer graphics at Ford Motor Company
Authors: Bliss Frank W. 
Published: November 2005

Over the past fourteen years the Ford Motor Company actively pursued the development and use of interactive computer graphics in the design and manufacture of automobiles. The success of Ford's pioneering efforts in the area of minicomputer graphics led to widespread acceptance and support for graphics within the corporation. This in turn led to a rapid expansion of computer graphics equipment. The advent of numerous Federal regulations in the areas of fuel economy, emissions control, and safety has generated additional Corporate interest in the use of computer graphics to help solve these difficult problems. Use of the Ford Computer Graphics System, as well as various commercially available turnkey computer graphics systems, has contributed substantially to cost reductions, improved productivity, and better documentation and control.
This paper describes the on-going computer graphics effort at Ford Motor Company. A brief history of computer graphics is presented along with a detailed description of the Ford Computer Graphics System and the commercial systems. A few applications involving the various graphics systems are discussed. These include design activity at several design and manufacturing areas which are major users of graphics equipment.
Next, four computer graphics-related projects presently receiving considerable attention are described. They include communications between graphics systems, a graphics information system and the use of graphics in both structural analysis and numerical control.
Finally, some indication of where computer graphics is headed in the future is presented.
The workstation concept of GKS and the resulting conceptual differences to the GSPC core system
Authors: Encarnacao J. , Enderle G. , Kansy K. , Nees G. , Schlechtendahl E. G. , Weiss J. , Wißkirchen P. , Germany W. 
Published: November 2005

GKS has evolved from a long process of national /1,2,3,4/ and international /5,6/ discussion on standardization of graphical systems. One of the basic principles of the Graphical Kernel System GKS is the concept of workstations that are used to address a display terminal with several input devices. This is a basic conceptual difference to the GSPC core system /6/, which will be discussed in this paper.
A workstation represents a collection of graphical devices that are operated in a coordinated fashion by an operator at a given site. The whole workstation is treated in GKS as one logical unit.
GKS features two dimensional output to and input from single or multiple workstations. Besides basic line drawing primitives raster graphics primitives are supported. The coordinates are transformed in a two-stage transformation process where the first stage can be set for each primitive and the second can be set for each workstation. Furthermore the setting of a workstation specific pen and text table allows control of the appearance of all primitives on the corresponding workstation.
A segment facility provides means for structuring a picture in subparts. Segments may be created and deleted, the segment attributes may be dynamically modified, and the segments may be transformed. They can be displayed simultaneously or alternatively on different workstations. A device independent segment storage serves for inserting segments into other segments.