Showing papers on "Graphics published in 1987"

Strategic approaches to drug design. I. An integrated software framework for molecular modelling.

Abstract: An integrated molecular graphics and computational chemistry framework is described which has been designed primarily to handle small molecules of up to 300 atoms. The system provides a means of integrating software from any source into a single framework. It is split into two functional subsystems. The first subsystem, called COSMIC. runs on low-cost, serial-linked colour graphics terminals and allows the user to prepare and examine structural data and to submit them for extensive computational chemistry. Links also allow access to databases, other modelling systems and user-written modules. Much of the output from COSMIC cannot be examined with low level graphics. A second subsystem, called ASTRAL, has been developed for the high-resolution Evans & Sutherland PS300 colour graphics terminal and is designed to manipulate complex display structures. The COSMIC minimisers, geometry investigators, molecular orbital displays, electrostatic isopotential generators and various interfaces and utilities are described.

Walkthrough—a dynamic graphics system for simulating virtual buildings

Abstract: As part of our graphics research into virtual worlds, we are building a tool for an architect and his client to use for rapid prototyping of buildings by visually “walking through” them in order to refine specifications.Our first prototype simulated the new UNC Computer Science building with some 8000 polygons. BSP-tree software on the Adage Ikonas gave a colored, shaded perspective view every 3-5 seconds while the user moved a cursor in real-time over floorplans shown on the Vector-General 3300.The current (third) version uses Pixel-Planes to generate 9 updates/second, view images shown 4' x 6' by projector.Active short- and long-term research questions include speed-up, stereo, a 6-DoF interface with eye-level defaults, and an interactive model-building, model-changing system.

Task-Action Grammars: A Model of the Mental Representation of Task Languages

Abstract: A laboratory experiment was conducted to assess the influence of graphical and color-enhanced information presentation on information use and decision quality in a simulation setting. This is the third in a series of studies examining the effects of colors and graphics in a managerial decision making task. The findings reported in this paper indicate that graphical presentations are more useful when evaluating information in order to determine promising directions in the search for an optimal solution bit when the task requires the determination of exact data values for computational purposes, graphical reports are less useful than tabular ones. Benefits of color include taking fewer iterations to complete the task. However, these benefits are associated more strongly with the graphical report as indicated by the significantly higher use of color enhanced graphical reports over monochromatic ones. The benefits of color are also restricted to the early stages in the decision task with color graphic report usage dropping sharply over time.

The Psychology of illustration

Abstract: 1. Three Hundred Years of Illustrations in American Textbooks.- Illustrations in Pre-Eighteenth-Century Materials, Precursors to American Textbooks.- Illustrations in Eighteenth-Century American Textbooks.- Early-Nineteenth-Century Textbooks.- Later-Nineteenth-Century Textbooks.- The Use of Color.- The Move Toward Ethnicity and Equality.- Conclusions.- Acknowledgments.- References and Bibliography.- 2. The Analysis of Illustration in Theory and Practice.- Analytical Model.- Visual Factors.- Levels of Communication.- Elements.- Relevant Findings.- Syntactic Unity (the Bounds of a Single Image).- Semantic Unity (Recognition of an Image).- Pragmatic Unity (the Role of Experience and Context in Recognition).- Syntactic Location (Basic Pictorial Depth Perception).- Semantic Location (the Contribution of Image Identification to Perception of Pictorial Depth).- Pragmatic Location (Developmental and Experiential Factors in Pictorial Depth Perception).- Syntactic Emphasis (the Attraction and Direction of Attention Independently of Meaning).- Semantic Emphasis (Descriptive Images Having Widespread Attraction and Direction Value).- Pragmatic Emphasis (the Influence of Extrapictorial Factors on Scanning Behavior).- Syntactic Text Parallels (Spatial and Temporal Relationsips Between Text and Illustration).- Semantic Text Parallels (the Naming of an Image).- Pragmatic Text Parallels (the Conceptual Relationships Between Text and Illustration).- Analysis in Action.- Summary.- References.- 3. A Naturalistic Inquiry into Illustration in Instructional Textbooks.- Publishing Illustrations.- The Decision-Making Process.- Why More or Less?.- Updated Illustrations.- The Role of Research.- Why Illustrate?.- Teachers and Illustrations.- The Illustrations Themselves.- Quantity of Illustration.- Type of Illustration.- Complexity of Illustration.- Location of Illustration.- Overview and Directions.- References.- Appendices.- 4. Visual Displays in Basal Readers and Social Studies Textbooks.- Our Domain of Study.- The Big Issues.- Research on Effective Written/Visual Communications.- Method.- Sample.- Type of Visual Display.- Location.- Units of Analysis.- Functions.- Analyses of the Source of Reference.- Results and Discussion.- Type and Location of Visual Displays.- Physical Relations between Text and Iconographic Forms.- The Function of Visual Displays.- Analyses of Reference Source.- General Discussion.- References.- 5. Designing Pictorial/Verbal Instruction: Some Speculative Extensions from Research to Practice.- Case Study 1.- Case Study 2.- Case Study 3.- Case Study 4.- Case Study 5.- Other Illustration Design Problems and Principles.- Relation of Words and Pictures.- Functions of Pictures.- Closing Comparative Examples.- Closing Remarks.- References.- 6. Computer Graphics in Learning and Instruction.- Review of Research.- Graphics in CAI.- Student Applications.- Types of Computer Graphics.- Vector Graphics.- Raster Graphics.- Mixed Systems.- Graphics Workstations.- Computer and Memory.- Disk Storage.- Input Devices.- Display Systems.- Output Devices.- Graphics Software Categories and Capabilities.- Text and Words.- Graphs and Charts.- Drawing Packages.- Painting Packages.- Libraries of Electronic "Clip Art".- Animation and Special Effects.- A Framework for Student Applications.- Prior Research on Graphics in Instruction.- Three types of Graphics.- The Computer Advantage.- Student Applications in Science Learning.- Microcomputer Workstations.- Science Graphics.- Project Implementation.- Informal Evaluation.- Directions for Future Research.- References.

Towards a comprehensive user interface management system

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

Human factors testing in the design of Xerox's 8010 “Star” office workstation

Abstract: Integral to the design process of the Xerox 8010 “Star” workstation was constant concern for the user interface. The design was driven by principles of human cognition. Prototyping of ideas, paper-and-pencil analyses, and human-factors experiments with potential users all aided in making design decisions. Three of the human-factors experiments are described in this paper: A selection schemes test determined the number of buttons on the mouse pointing device and the meanings of these buttons for doing text selection. An icon test showed us the significant parameters in the shapes of objects on the display screen. A graphics test evaluated the user interface for making line drawings, and resulted in a redesign of that interface.

A parallel processor architecture for graphics arithmetic operations

Abstract: Interactive 3D graphics applications require significant arithmetic processing to handle complex models, particularly if realistic rendering techniques are used. Current semiconductor technology cannot provide the necessary performance without some form of multi-processing.This paper describes a graphics processor architecture which can be configured with an arbitrary number of identical processors operating in parallel. Each of the parallel processors can be programmed identically as if it were a single processor system, substantially simplifying software development and allowing complex rendering functions to take advantage of the multiple processors. The architecture described is able to achieve extremely high performance while allowing the price/performance of the system to be optimized for a given application.Techniques are described for handling graphics command distribution, sequencing of commands which must be processed in order, parallel processing of graphics primitive picking, and handling inquiry (read-back) commands.

Computer assisted graphic teleconferencing method and apparatus

Abstract: An audiographic telephone conferencing system between a plurality of parties or users either directly connected or through a piece of apparatus known as a "meet me bridge" over voice grade telephone lines Each user has a programmed personal computer which controls a programmable or "smart" modem, cassette recorder/player, and speakerphone A protocol is implemented by the software, ie the computer program, in each of the computers which puts its respective modem in a listening mode to monitor the phone line at all times The computer is further programmed and includes a memory for storing and transmitting graphics presently on hand to other user(s) via the modem during a teleconference or alternatively receive graphics from another user, or it can switch to an external graphics program to make new or modify existing graphic images However, one is unable to speak on the telephone line while a graphic is being transmitted during a teleconference due to the fact that voice alternates with graphic transmissions

Real-time display and manipulation of 3-D medical objects: the Voxel processor architecture

Abstract: The fundamental problems associated with the interactive display, manipulation, and editing of three-dimensional (3-D) objects obtained from medical imaging systems such as CT, PET, and MRI are addressed. Software, hardware, and firmware techniques for shaded graphics display of medical objects are described and evaluated in terms of flexibility and performance. A special purpose multiprocessor architecture (the Voxel Processor architecture) developed specifically for medical research, clinical diagnosis, and surgical planning is presented. The Voxel Processor implements a shaded graphics display system with rotation, scaling, translation, slice planes and tone scale transformations on gray-scale data in true real time. The high-speed image generation algorithms exploit the ability to partition object space and require only simple arithmetic and logical operations. Minimal preprocessing steps are required to prepare object data for the Voxel Processor, and the data are always readily accessible for analysis or editing. The architecture is highly structured and is ideally suited for VLSI implementation.

Parallel computers for graphics applications

Abstract: Specialized computer architectures can provide better price/performance for executing image processing and graphics applications than general purpose designs. Two processors are presented that use parallel SIMD data paths to support common graphics data structures as primitive operands in arithmetic expressions. A variant of the C language has been implemented to allow high level language coding of user applications on these processors. High level programming support is designed into the processor architecture that implements parallel object data typing and parallel conditional evaluation in hardware.

Research in Statistical Graphics

Abstract: Three active areas of research in statistical graphics are methodology, computing, and graphical perception. The five articles in this special section provide a good representation of these areas. Dynamic graphical methods, which involve a tight weaving of methodological and computing issues, are a particularly exciting topic of research; dynamic graphics will soon have a major impact on how data are analyzed. Evaluation of graphical inventions is difficult. Certain visualization issues can be evaluated by studies in graphical perception. At the moment, however, the performance of most graphical methods can be studied only by rigorous field testing in which the methods are used to analyze a large number of data sets. A bibliography is provided to allow readers to begin a study of any of the major areas of statistical graphics.

Microcomputer‐aided reconstruction: a system designed for the study of 3‐D microstructure in histology and histopathology

Abstract: We have designed a microcomputer system to reproduce 3-D tissue structures graphically from serial microscopic sections. The system, based on a Hewlett-Packard model 310 desktop computer, comprises a floppy disc drive, a hard-disc that extends the available user memory by adding 40 Mbytes, a colour memory-mapped graphics display, a graphics tablet and a graphics printer. A set of serial 2-D images, manually extracted from serial sections using a microprojector, are digitized on the tablet by tracing the contours of the structure of interest; up to ten different structures can be inputted and reproduced using a 'hidden line' effect. The software, written mainly in HP-BASIC 4.0, produces 3-D pictures of a tissue structure either as a 'stack of slices' with or without being 'tiled' with triangular patches, or in 'wire framing'. Any angle of rotation around the x, y and z axes is assigned for the image to be reconstructed, allowing the operator to obtain the best perspective. The system also discloses the internal connectivity of an object by reducing the structure to a network diagram; this is especially useful in analysing the topological properties of tissue structure. It is shown how, in some examples, the system contributes to a better understanding of tissue microstructures and their morbid changes and how, as an effective tool in morphology, it will aid future studies of histology and histopathology.

Animation using temporal constraints: an overview of the animus system

Abstract: Algorithm animation has a growing role in computer-aided algorithm design, documentation, and debugging, because interactive graphics is a richer channel than text for communication. Most animation is currently done laboriously by hand, and it often has the character of canned demonstrations with restricted user interaction. Animus is a system that allows for easy construction of an animation with minimal concern for lower-level graphics programming. Constraints are used to describe the appearance and structure of a picture as well as how those pictures evolve in time. The implementation and support of temporal constraints are substantive extensions to previous constraint languages that had only allowed for the specification of a static state. Use of the Animus system is demonstrated in the creation of animations of dynamic mechanical and electrical circuit simulations, sorting algorithms, problems in operating systems, and geometric curve drawing algorithms.

Picking in a graphics system

Abstract: A method is described for improving the responsiveness and accuracy of a graphics system to user-initiated picking actions. In this method, the visual cueing and pick window positioning components of the graphics system tracking/picking function are temporarily separated at the time the user attempts to pick. By handling these two components of the tracking/picking function independently, both type 1 (failure to pick the desired item) and type 2 (picking an undesired item) errors are prevented. This translates into greater productivity for the graphics system user.

Flow visualization of CFD using graphics workstations

Abstract: High performance graphics workstations are used to visualize the fluid flow dynamics obtained from supercomputer solutions of computational fluid dynamic programs. The visualizations can be done independently on the workstation or while the workstation is connected to the supercomputer in a distributed computing mode. In the distributed mode, the supercomputer interactively performs the computationally intensive graphics rendering tasks while the workstation performs the viewing tasks. A major advantage of the workstations is that the viewers can interactively change their viewing position while watching the dynamics of the flow fields. An overview of the computer hardware and software required to create these displays is presented. For complex scenes the workstation cannot create the displays fast enough for good motion analysis. For these cases, the animation sequences are recorded on video tape or 16 mm film a frame at a time and played back at the desired speed. The additional software and hardware required to create these video tapes or 16 mm movies are also described. Photographs illustrating current visualization techniques are discussed. Examples of the use of the workstations for flow visualization through animation are available on video tape.

Toy vehicle with graphics display

Abstract: A toy vehicle construction is disclosed which has been particularly configured so that the toy vehicle exhibits animated characteristics. To this end, a liquid crystal graphics display is provided on the chassis of the vehicle, with the graphics display particularly configured to display a plurality of simulated life functions. An associated micro-processor effects operation and control of the graphics display, with additional sound-generating, light-emitting, and detecting devices further provided to further lend to the animated nature of the device.

Full speed animation system for low-speed computers and method

Abstract: Graphics display systems are used to display animated images, generated from a sequence of images (D) developed by an artist, and projected using a conditional replacement technique, in a manner as directed by a series of commands (E), given to the program by the artist. The method works for systems of any resolution and number of colors. To facilitate the process is broken into two steps, development (A) and projection (B). This eliminates all activities from the actual projection effort that do not directly contribute to it, enabling faster operation. In combination with the storage and display techniques, which only note any changes from one image to the next, this allows true animation displays not normally attainable with given equipment.

Distributed Interactive Graphics Applications in Computational Fluid Dynamics

Abstract: Implementation of two distributed graphics pro grams used in computational fluid dynamics is discussed. Both programs are interactive in na ture. They run on a CRAY-2 supercomputer and use a Silicon Graphics Iris workstation as the front-end machine. The hardware and supporting software are from the Numerical Aerodynamic Simulation project The supercomputer does all numerically intensive work and the workstation, as the front-end machine, allows the user to perform real-time interactive transformations on the displayed data. The first program was written as a distributed program that computes particle traces for fluid flow solutions existing on the su percomputer. The second is an older post-pro cessing and plotting program modified to run in a distributed mode. Both programs have realized a large increase in speed over that obtained using a single machine. By using these pro grams, one can learn quickly about complex features of a three-dimensional flow field. Some color results are presented.

High performance graphics workstation

Abstract: A stand-alone graphics workstation including a digital computer host and a graphics processing subsystem is disclosed. Address data relating to the graphics subsystem components is mapped into the host system virtual memory. The application processes residing in the host are thereby able to communicate directly with the graphics subsystem components, as, e.g. the structure memory, without the need of a direct memory access hardware arrangement or device drivers.

"?": A Context-Sensitive Help System Based on Hypertext

Abstract: Commercial on-line help systems are still largely text-based using TTY interfaces, even on bitmap graphics workstations. Context-sensitive help for on-screen objects on workstations is one important feature lacking in today's help systems. This paper describes a new system called "?"(FOOTNOTE: "?" is pronounced "eh?"; "eh" is derived from err_help which is described in the implementation section.) based on hyper-text which mixes text, graphics and movies and allows the user to peruse the entire help database through the use of reference buttons.

Computer Graphics in Learning and Instruction

Abstract: Unlike textbook images that are static and television images that permit only passive viewing, computer graphics can be drawn dynamically and interactively on the display screen. For years, most computer games have featured animated, interactive computer graphics. Now computer-based tutorials on a wide range of topics are available that present new information to learners via dynamic, interactive graphics. One of the most recent developments in the area of computer graphics is the educational use of graphics applications software—the visual equivalent of word processing software. With it, learners can create their own computer graphics on the display screen and then use the computer to review the images in a variety of ways. Images can be enlarged, flipped, rotated, animated, duplicated, colored, sized up or down, moved around the screen, deleted, and more—all without programming. It is this dynamic and interactive aspect of computer graphics that is so appealing to learners and holds great promise for improving instruction.

Method and system for printing graphics and text from vector-based computer aided source information

Abstract: A method and conversion system are provided for enabling a laser printer or the like to produce drawings including graphics and text from input supplied by a computer aided design (CAD) system which allows text font style to be selected as desired and which produces curved lines as smooth curves. The preferred apparatus and method convert entity descriptions supplied by the CAD system in vector notation into signal representative of entity descriptions in device notation whereby the output device uses the signals to create an entity image according to the type of entity such as an arc, text, or the like, and according to corresponding plotting data defining the parameters of the entity. The system and method also allow the user to enter signals representative of the desired font style of the text characters, gray scale levels, and reverse image if desired while also creating curved line images as smooth curves rather than as a series of straight short line segments.

Sight-dedicated computer graphics machine

Abstract: The. architecture of, and a performance estimate for, the dedicated graphics processor - SIGHT, a high-speed ray tracing machine, are presented. Ray tracing is a vector calculation in 3–dimensional (3–D) space and each ray to be traced can be calculated independently. The SIGHT is designed so that it speeds up the execution of the ray tracing algorithm at two levels of parallel operations: the pixel-level parallel operation by multiprocessors and the instruction-level parallel operation by the new processing element (PE) architecture. The features of the PE are:

Graphics Aided Interactive Analysis of Radial Distribution Networks

Abstract: This paper presents an interactive graphics package for distribution system analysis. The radial operation of the distribution networks is exploited in order to effect a fast and accurate calculation of the power flows, the voltage drops and the power losses at the various segments of a feeder for a given set of typical load curves. The algorithms developed are based on an efficient method to store the network topology and can easily accommodate changes in the infeeding nodes and variations in the network structure due to switching operations. The interactive environment allows the user to obtain the results of his studies against the one-line diagram of the network and effect changes in it in basically diagrammatic terms. The package requires very modest computer resources and provides planning and operating engineers with a powerful tool to conduct analytical distribution system studies with ease and flexibility.

Computer graphics for quality control in the INAA of geological samples

Abstract: A data reduction system for the routine instrumental activation analysis of samples is described, with particular emphasis on interactive graphics capabilities for evaluating analytical quality. Graphics procedures have been developed to interactively control the analysis of selected photopeaks during spectral analysis, and to evaluate detector performance during a given counting cycle. Graphics algorithms are also used to compare the data on reference samples with accepted values, to prepare quality control charts to evaluate long term precision and to search for systematic variations in data on reference samples as a function of time.

Generating Images For A Time-Multiplexed Stereoscopic Computer Graphics System

Abstract: Stereoscopic images provide unique visual information not available in the planar computer-graphics images which have come to be called "3-D." However, special care must be taken in generating stereoscopic pairs of images for computer graphics. The creation of stereoscopic images requires observing special constraints which do not occur in generating planar "3-D" graphics, in order to produce three-dimensional images which are not distorted, are comfortable to view for long periods, and which appear to have appropriate z-axis depth. The interrelated stereoscopic factors of convergence, accommodation, homologous points, retinal disparity, and binocular symmetry are explained. The effects on the stereoscopic CRT image of positive, negative, zero, and uncrossed parallax values are described, and various special problems and solutions related to images with negative parallax are discussed. Limitations prescribed by the accommodation/convergence ratio and by the use of off-screen effects are proposed. Procedures are offered to writers of software for the creation of properly-prepared images for display on a flickerless time-multiplexed stereoscopic CRT display system, with consideration given to extrastereoscopic cues, screen geometry, and initialization parameters. A useful stereoscopic camera model is described, in which the mapping of points in world coordinates is designated, along with parallax governors to prevent the display of discomfort-producing images. Algorithms are given for the generation of images in the correct format for the system described.

Stereo Animation for Very Large Data Bases: Case Study- Meteorology

Abstract: As technological advances give rise to increasingly more powerful computers, applied mathematicians are able to simulate phenomena of considerable complexity using nurmerical models. One of the problems is how to transform the volminuous output data from a numerical form to a visual one, which is easier for humans to comprehend. This article analyzes a case study from the field of meteorology. A weather simulation, program produces numerical output which defines the values of several variables as functions of the three spatial parameters and time. The output of this model is then used as the input to our grphic rendering system, which displays these complex data sets using stereo animation, employing novel techniques to add realism in the animation sequences. We take advantages of the special geometrical configuration to reduce the computation time by about two orders of magnitude. The value our approach is that our techniques for representing four-dimensional data sets can easily be extended to display phenomena in other disciplines.