bluuebunny/crossref_metadata_2025_split huggingface dataset:
ATOMLLL
Authors: Max Nelson L. 
Published: November 2005

The ATOMS program, written at Bell Telephone Laboratory, is capable of determining the visible portions of a scene consisting of interpenetrating spheres and cylinders, put together to represent “space-filling” or “ball-and-stick” molecular models. The Lawrence Livermore Laboratory version contains enhancements to add shading and highlights, and to render the spheres on film as ellipses, so they will appear round when projected in various wide-screen formats.
The visible parts of each sphere or cylinder are shaded by a minicomputer controlling the film recorder, thus releasing the main computer from transferring the millions of intensity values for each frame. The minicomputer is microprogrammed with an efficient algorithm for the intensities, which uses the color look-up tables in the film recorder to store the reflectance as a function of angle of incidence.
Computer drafting of stones, wood, plant and ground materials
Authors: Yessios Chris I. 
Published: November 2005

Architectural presentation drawings frequently require the drafting of stones, wood patterns, plants and ground materials, which, contrary to the majority of drafting tasks, cannot rely on repetitious procedures. This paper discusses and illustrates computer implemented algorithms which generate graphic representations of the above materials.
Simulating a process known to be applied in practice is certainly a sound approach, and one such algorithm, applicable for the derivation of stone walls, is presented, But the majority of the algorithms discussed are based on a technique which introduces randomly generated disturbances on initially regular patterns. The latter algorithms in particular have produced highly satisfactory graphic representations, which include frequently hand-made qualities.
Special session on large scale applications of computer charting and mapping in industry (Panel Session)
Authors: Paller Alan , d'Hondt Walter , Dahl David , Dupree Robert L. 
Published: November 2005

1. It will demonstrate, with specific examples, the types of planning, justification, expense, and results that are part of the implementation of new computer graphics applications; and,
2. It will attempt to bring out the major barriers to implementation of computer graphics in large organizations and how those barriers may be overcome.
The session is designed to help developers of the new advances in computer graphics software and hardware technology better understand the environments in which their tools will be used in order to optimize the use of the tools they develop. Too often developers of new tools have little opportunity to “get inside the heads” of the managers who will take these new tools and implement them. Through speakers and discussion, the session will draw together the experiences of people who have done the hard work necessary to estimate the costs and benefits and persuade top management that the project is worthwhile, to find the right hardware and software, and to train the staff to work with the new systems.
Interactive color map displays of domestic information
Authors: Dalton J. , Billingsley J. , Quann J. , Bracken P. 
Published: November 2005

Governmental decision makers require an increasing variety and volume of information in order to formulate effective policies, plans, and legislation. Moreover, rapid access to this broad body of information is critical to timely and effective governmental action. This paper describes a recent joint project undertaken by the NASA/Goddard Space Flight Center and the Bureau of the Census at the request of the Executive of the President to demonstrate the potential of graphic information display technology for the rapid delivery and effective display of Federal statistics. This project resulted in the development of a prototype Domestic Information Display System which was demonstrated to President Carter, members of Congress, and their respective staffs in June 1978.
The Domestic Information Display System is an interactive, menu-driven software system which produces single and bivariate choropleth maps of socio-economic data by county at the national and state level, and by census tract for Standard Metropolitan Statistical Areas (SMSA's). Selected subareas of national and SMSA maps may be dynamically enlarged to show greater detail. Histogram displays may be selected to show statistical as well as geographic structure.
The system is minicomputer-based and utilizes the image manipulation capabilities of a raster-scan color graphics terminal designed at NASA/Goddard as part of the Atmospheric and Oceanographic Information Processing System (AOIPS) which was adapted to demonstrate the potential of a Domestic Information Display System. The system is highly interactive and can produce a color map display within seconds of the selection of a data item from a menu.
This paper discusses the operation of the Domestic Information Display System, presents sample output products, and describes in detail the software and hardware organization through which the system flexibility and rapid response were achieved.
Parallel processing techniques for hidden surface removal
Authors: Kaplan Michael , Greenberg Donald P. 
Published: November 2005

Previous work in the hidden-surface problem has revealed two key concepts. First, the removal of non-visible surfaces is essentially a sorting problem. Second, some form of coherence is essential for the efficient solution of this problem.
In order to provide real-time simulations, it is not only the amount of sorting which must be reduced, but the total time required for computation. One potentially economic strategy to attain this goal is the use of parallel processor systems. This approach implies that the computational time will no longer be dependent on the total amount of sorting, but more on the appropriate division of responsibility.
This paper investigates two existing algorithmic approaches to the hidden-surface problem with a view towards their applicability to implementation on a parallel machine organization. In particular, the statistical results of a parallel processor implementation indicate the difficulties stemming from a loss of coherence and imply potentially important design criteria for a parallel configuration.
Stochastic modeling in computer graphics
Authors: Fournier Alain , Fussell Don 
Published: November 2005

A recurrent problem in generating realistic pictures by computers is to represent natural irregular objects and phenomena without undue time or space overhead. We develop a new and powerful solution to this problem by modeling objects as sample paths of stochastic processes. Of particular interest are those stochastic processes which previously have been found to be useful models of the natural phenomena to be represented. One such model applicable to the representation of terrains, known as “fractional Brownian motion”, has been proposed by B. Mandelbrot.
The value of a new approach to object modeling in Computer Graphics depends largely on the efficiency of the techniques used to implement the model. We introduce here a new, efficient algorithm for rendering realistic surfaces defined using the stochastic process mentioned above. A major advantage of this technique is that it allows us to compute the surface to arbitrary levels of detail without increasing the database. Thus objects with complex appearance can be displayed from a very small database. The character of the surface can be controlled by merely modifying a few parameters. A similar change allows complex motion to be created inexpensively.
A 3-dimensional representation for fast rendering of complex scenes
Authors: Rubin Steven M. , Whitted Turner 
Published: November 2005

Hierarchical representations of 3-dimensional objects are both time and space efficient. They typically consist of trees whose branches represent bounding volumes and whose terminal nodes represent primitive object elements (usually polygons). This paper describes a method whereby the object space is represented entirely by a hierarchical data structure consisting of bounding volumes, with no other form of representation. This homogencity allows the visible surface rendering to be performed simply and efficiently.
The bounding volumes selected for this algorithm are parallelepipeds oriented to minimize their size. With this representation, any surface can be rendered since in the limit the bounding volumes make up a point representation of the object. The advantage is that the visibility calculations consist only of a search through the data structure to determine the correspondence between terminal level bounding volumes and the current pixel. For ray tracing algorithms, this means that a simplified operation will produce the point of intersection of each ray with the bounding volumes.
Memory requirements are minimized by expanding or fetching the lower levels of the hierarchy only when required. Because the viewing process has a single operation and primitive type, the software or hardware chosen to implement the search can be highly optimized for very fast execution.
A linear time exact hidden surface algorithm
Authors: Franklin Wm Randolph 
Published: November 2005

This paper presents a new hidden surface algorithm. Its output is the set of the visible pieces of edges and faces, and is as accurate as the arithmetic precision of the computer. Thus calculating the hidden surfaces for a higher resolution device takes no more time. If the faces are independently and identically distributed, then the execution time is linear in the number of faces. In particular, the execution time does not increase with the depth complexity.
This algorithm overlays a grid on the screen whose fineness depends on the number and size of the faces. Edges and faces are sorted into grid cells. Only objects in the same cell can intersect or hide each other. Also, if a face completely covers a cell then nothing behind it in the cell is relevant.
Three programs have tested this algorithm. The first verified the variable grid concept on 50,000 intersecting edges. The second verified the linear time, fast speed, and irrelevance of depth complexity for hidden lines on 10,000 spheres. This also tested depth complexities up to 30, and showed that perspective scenes with the farther objects smaller are even faster to calculate. The third verified this for hidden surfaces on 3000 squares.
Dynamic scan-converted images with a frame buffer display device
Authors: Jackson J. H. 
Published: November 2005

A color interactive display system which produces images of three-dimensional polygons and labels on a frame buffer display device is being developed. The entire image is scan converted and written into the frame buffer whenever it is modified. Since an entire image cannot be written into the frame buffer faster than 4.6 frames per second for the particular device chosen, an illusion of continuous motion cannot be supported. However, a rate of 3 frames per second has been found sufficient to provide feedback to continuous user input.
In order to achieve this frame rate for a reasonably complex picture, the display device has been microprogrammed to accept run length encoded data and text, and the instruction set of the computer has been extended by microprogramming special-purpose instructions which perform visible surface calculations. These microprograms currently can process a scene which consists of up to 170 polygons at 3 frames per second.
Adaptation of scan and slit-scan techniques to computer animation
Authors: Parke Frederic I. 
Published: November 2005

The adaptation and generalization of scan and slit-scan animation stand techniques for use in computer generated animation is discussed. Scan and slit-scan techniques are based on moving artwork, camera, and, for slit-scan, a thin aperture while the camera shutter is open. These processes can be described as selectively sampling an environment over time and recording the result as a single image. Sequences of such images form the animated film. Rather than use mechanical means to accomplish this, it is possible to develop algorithms which mimic this processes but are based on sampling dynamic environment descriptions to generate computer produced images.
The use of computer graphics allows these techniques to be generalized in ways difficult or impossible even with very elaborate animation stands. Use of multiple independent scanning apertures and three-dimensional environments are natural generalizations.
The exact algorithms used depend on the characteristics of the graphics systems used. An approach based on using a real-time shaded graphics system and an approach using frame buffer systems are outlined. The first approach can also be applied to refresh vector graphics systems.
B-spline surfaces for ship hull design
Authors: Rogers David F. , Satterfield Steven G. 
Published: November 2005

The use of true sculptured surface descriptions for design applications has been proposed by numerous authors. The actual implementation and use of interactive sculptured surface description techniques for design and production has been limited. The use of such techniques for ship hull design has been even more limited. The present paper describes a preliminary implementation of such a system for the design of ship hulls and for the production of towing tank models using numerical control techniques. The present implementation is based on a Cartesian product B-spline surface description. Implementation is on an Evans and Sutherland Picture System supported by a PDP-11/45 minicomputer.
The B-spline surface is manipulated by its associated polygonal net. Both surface and net are three-dimensional. Techniques both good and bad for 3-D picking of a polygon point when the net, its associated surface, and the 3-D picking cue independently exist and can be independently manipulated in three space are presented and discussed.
The shape of a B-spline surface of fixed order is controlled by the location of the polygon net points, the number of multiple points at a particular net point, and the knot vector. Frequently multiple points imply multiple knot vectors. Practical techniques for controlling and shaping the surface with and without this assumption are discussed and the results illustrated.
Experience attained by interactively fitting a single fourth order B-spline surface patch to the forebody half of an actual ship hull described by three dimensional digitized points is discussed and the results illustrated.
Natural and efficient viewing parameters
Authors: Michener James C. , Carlbom Ingrid B. 
Published: November 2005

The viewing scheme in the Core Graphics System is based on a unified approach to the specification of the viewing parameters for all types of planar geometric projections. As a result, the specification of some of the viewing parameters is inconsistent with traditional ways of specification and will often be found unnatural for use in certain application areas. Additionally, this choice of viewing parameters leads to inefficient implementations of viewing parameter modification, particularly in a high-performance graphics system which supports transformations in hardware or firmware.
The natural ways to specify the different viewing parameters are discussed and efficiency considerations for viewing implementations are described. The Core System viewing scheme is evaluated in terms of its naturalness and efficiency of implementation. An alternate viewing scheme is proposed that provides viewing parameters that are more natural for many applications and that can he modified more efficiently.
Graphics standards status report (Panel Session)
Authors: tenHagen P. , Chin Janet , Bono P. , Encarnacao J. , Michener J. , Bono Peter 
Published: November 2005

Two status reports will be presented. The first report describes the activities of Working Group 2 (Computer Graphics) of the International Standards Organization Subcommittee on Programming Languages (ISO TC97/SC5/WG2). Actions taken in recent WG2 meetings in October, 1979, and June, 1980, will be covered. Significant proposals being examined by WG2 include GKS, a German-designed 2D graphics package derived from the SIGGRAPH GSPC Core System proposals, and Videotex, a Canadian-designed protocol text communication that includes geometrically coded picture images.
The second status report describes the recent activities of the American National Standards Institute (ANSI) Technical Committee X3H3, Computer Graphics. This includes the committee status, international activities, key technical issues, and future plans.
The display of characters using gray level sample arrays
Authors: Warnock John E. 
Published: November 2005

Character fonts on raster scanned display devices are usually represented by arrays of bits that are displayed as a matrix of black and white dots. This paper reviews a filtering and sampling method as applied to characters for building multiple bit per pixel arrays. These arrays can be used as alternative character representations for use on devices with gray scale capability. Discussed in this paper are both the filtering algorithms that are used to generate gray scale fonts and some consequences of using gray levels for the representation of fonts including:
1. The apparent resolution of the display is increased when using gray scale fonts allowing smaller fonts to be used with higher apparent positional accuracy and readability. This is especially important when using low resolution displays.
2. Fonts of any size and orientation can be generated automatically from suitable high precision representations. This automatic generation removes the tedious process of “bit tuning” fonts for a given display.
A scan line algorithm for displaying parametrically defined surfaces
Authors: Blinn James F. 
Published: November 2005

This paper presents a scan line algorithm for drawing picture of parametrically defined surfaces. A scan line algorithm is characterized by the order in which it generates the picture elements of the image. These are generated left to right, top to bottom in much the same was as a picture is scanned out on a TV screen. Parametrically defined surfaces are those generated by a set of bivariate functions defining the X, Y and Z position of points on the surface. The primary driving mechanism behind such an algorithm is the inversion of the functions used to define the surface. To keep the algorithm general enough to apply to a wide variety of functional forms, this inversion is done numerically. It is only required to provide mechanism for evaluating the function and its derivatives at any parametric location.
The algorithm proceeds in two phases. First, a numerical search is made to find the local maxima of the Y definition function within the desired parameter ranges. These determine when portions of the surface first become visible as the scan plane progresses down the screen. Secondly, the actual scan conversion process is performed, maintaining a list of segments of the surface intersecting the current scan plane. As the scan plane passes local maxima of the Y function new segments are added to the list. In addition, any existing segments are updated to reflect their intersection with the updated scan plane. All intersection calculations are performed by a bivariate Newton-Raphson solution of the defining equations. If the solution does not converge, it is due to the scan plane passing a local minimum, causing segments to be deleted from the active list. Finally, within one scan line, an X scan must be performed to generate the Z information about the surface for each picture element. This is also performed by a bivariate Newton-Raphson iteration with a different set of defining functions.
A microcomputer based system for automated pattern digitization and editing
Authors: Pavliscak T. J. , Stowell G. W. , Bailey M. J. 
Published: November 2005

Since the first microcomputer was produced in 1969 by Intel Corporation to support the functions of an intelligent terminal, the complexion of digital computers has changed radically. Microcomputers have been successfully applied to a wide variety of dedicated tasks requiring relatively slow calculation speeds and limited numeric accuracy.
However, little has been done to bring the LSI microprocessor into stand alone interactive graphics systems. This has been so probably because of the large data files and rapid computation speeds demanded by most interactive graphics applications. This paper outlines a hardware and software configuration for a microcomputer based graphics system developed in response to a need in the sewing industry for a low cost pattern digitizer.
A basic graphics package was written which renders both text and vectors on the storage terminal. Around this core, an application program was organized which permits an operator to log piercing point coordinate data from a scaled drawing. Output is then committed to paper tape for permanent storage and PROM for control of the sewing machine. Additional features allow for graphical editing of patterns, display of stored pattern “programs” from PROM or paper tape, and merging of new and/or old patterns.
Some proof of the success of this project was documented during final checkout, where the time to reduce a drawing to formatted binary on a control PROM was improved from about one man day to a matter of minutes.
Application of shape-preserving spline interpolation to interactive editing of photogrammetric data
Authors: Deimel L. E. , Doss C. L. , Fornaro R. J. , McAllister D. F. , Roulier J. A. 
Published: November 2005

The Integrated Photogrammetric Instrument Network (IPIN) is being designed and developed by the Defense Mapping Agency Aerospace Center in St. Louis, Mo. to meet database demands for terrain elevation information. IPIN is a network of computers and instrumentation dedicated to digitizing and editing photo-source terrain data [1]. Editing procedures are required because of digitizing errors inherent in the data-collection process. Some of these errors are random; others are systematic and predictable.
The techniques of one of the editing procedures being developed may find application elsewhere. The procedure of interest here involves smoothing raw data that have been collected by the operator of an analytical stereoplotter. When digitizing geomorphic features from aerial stereophotographs, the double-line drain (DLD) presents special problems. The digitizing of a DLD (a relatively broad river or stream) requires specifying trlples (x,y,z) (latitude, longitude, elevation) at points spaced along the length of each shoreline. The drain boundaries thus collected usually have acceptable latitude and longitude values. The elevation values, however, require smoothing.
A sensor simulation and animation system
Authors: Zimmerlin Timothy , Stanley John , Stone Warren 
Published: November 2005

A shaded computer graphics system for sensor simulation and animation must possess extensive capabilities. Sensor simulation involves scenes that are viewed, environments that produce tones in the scenes, and sensors that image the scenes. Animation centers on image generation, but data input, motion specification, and tone specification routines are very important for an effective system.
A unique system has been developed that models a variety of scenes, environments, and sensors. It possesses a balance of data input, motion and tone specification, and frame generation routines. The system possesses several user languages for data input. User defined sections of the scene can move. Visible, infrared, laser radar, and radar sensors have been modeled. The frame generator possesses advanced aliasing controls, textured shading, and a very fast list priority hidden surface algorithm. The system is used as a test bed for training simulators and sensor-based system simulation.