Conference stringclasses 6 values | Year int64 1.99k 2.03k | Title stringlengths 8 187 | DOI stringlengths 16 32 | Abstract stringlengths 128 7.15k ⌀ | Accessible bool 2 classes | Early bool 2 classes | AuthorNames-Deduped listlengths 1 24 | Award listlengths 0 2 | Resources listlengths 0 5 | ResourceLinks listlengths 0 10 |
|---|---|---|---|---|---|---|---|---|---|---|
Vis | 1,994 | Piecewise-linear surface approximation from noisy scattered samples | 10.1109/VISUAL.1994.346336 | We consider the problem of approximating a smooth surface f(x, y), based on n scattered samples {(x/sub i/, y/sub i/, z/sub i/)/sub i=1//sup n/} where the sample values {z/sub i/} are contaminated with noise: z/sub i/=f(x/sub i/, y/sub i/)=/spl epsiv//sub i/. We present an algorithm that generates a PLS (piecewise linear surface) f', defined on a triangulation of the sample locations V={(x/sub i/, y/sub i/)/sub i=1//sup n/}, approximating f well. Constructing the PLS involves specifying both the triangulation of V and the values of f' at the points of V. We demonstrate that even when the sampling process is not noisy, a better approximation for f is obtained using our algorithm, compared to existing methods. This algorithm is useful for DTM (digital terrain map) manipulation by polygon-based graphics engines for visualization applications.<<ETX>> | false | false | [
"Michael Margaliot",
"Craig Gotsman"
] | [] | [] | [] |
Vis | 1,994 | Progressive transmission of scientific data using biorthogonal wavelet transform | 10.1109/VISUAL.1994.346332 | An important issue in scientific visualization systems is the management of data sets. Most data sets in scientific visualization, whether created by measurement or simulation, are usually voluminous. The goal of data management is to reduce the storage space and the access time of these data sets to speed up the visualization process. A new progressive transmission scheme using spline biorthogonal wavelet bases is proposed in this paper. By exploiting the properties of this set of wavelet bases, a fast algorithm involving only additions and subtractions is developed. Due to the multiresolutional nature of the wavelet transform, this scheme is compatible with hierarchical-structured rendering algorithms. The formula for reconstructing the functional values in a continuous volume space is given in a simple polynomial form. Lossless compression is possible, even when using floating-point numbers. This algorithm has been applied to data from a global ocean model. The lossless compression ratio is about 1.5:1. With a compression ratio of 50:1, the reconstructed data is still of good quality. Several other wavelet bases are compared with the spline biorthogonal wavelet bases. Finally the reconstructed data is visualized using various algorithms and the results are demonstrated.<<ETX>> | false | false | [
"Hai Tao",
"Robert J. Moorhead II"
] | [] | [] | [] |
Vis | 1,994 | Restorer: a visualization technique for handling missing data | 10.1109/VISUAL.1994.346317 | Pseudocoloring is a frequently used technique in scientific visualization for mapping a color to a data value. When using pseudocolor and animation to visualize data that contain missing regions displayed as black or transparent, the missing regions popping in and out can distract the viewer from the more relevant information. Filling these gaps with interpolated data could lead to a misinterpretation of the data. The paper presents a method for combining pseudocoloring and grayscale in the same colormap. Valid data are mapped to colors in the colormap. The luminance values of the colors bounding areas of missing data are used in interpolating over these regions. The missing data are mapped to the grayscale portion of the colormap. This approach has the advantages of eliminating distracting gaps caused by missing data and distinguishing between those areas that represent valid data and those areas that do not. This approach was inspired by a technique used in the restoration of paintings.<<ETX>> | false | false | [
"Ray Twiddy",
"John Cavallo",
"Shahram M. Shiri"
] | [] | [] | [] |
Vis | 1,994 | Severe rainfall events in Northwestern Peru (visualization of scattered meteorological data) | 10.1109/VISUAL.1994.346298 | The ordinarily arid climate of coastal Peru is disturbed every few years by a phenomenon called El Nino, characterized by a warming in the Pacific Ocean. Severe rainstorms are one of the consequences of El Nino, which cause great damage. An examination of daily data from 66 rainfall stations in the Chiura-Piura region of northwestern Peru from late 1982 through mid-1983 (associated with an El Nino episode) yields information on the mesoscale structure of these storms. These observational data are typical of a class that are scattered at irregular locations in two dimensions. The use of continuous realization techniques for qualitative visualization (e.g., surface deformation or contouring) requires an intermediate step to define a topological relationship between the locations of data to form a mesh structure. Several common methods are considered, and the results of their application to the study of the rainfall events are analyzed.<<ETX>> | false | false | [
"Lloyd Treinish"
] | [] | [] | [] |
Vis | 1,994 | Spiders: a new user interface for rotation and visualization of n-dimensional point sets | 10.1109/VISUAL.1994.346318 | We present a new method for creating n-dimensional rotation matrices from manipulating the projections of n-dimensional data coordinate axes onto a viewing plane. A user interface for n-dimensional rotation is implemented. The interface is shown to have no rotational hysteresis.<<ETX>> | false | false | [
"Kirk L. Duffin",
"Bill Barrett"
] | [] | [] | [] |
Vis | 1,994 | Strata-various: multi-layer visualization of dynamics in software system behavior | 10.1109/VISUAL.1994.346322 | Current software visualization tools are inadequate for understanding, debugging, and tuning realistically complex applications. These tools often present only static structure, or they present dynamics from only a few of the many layers of a program and its underlying system. This paper introduces "PV", a prototype program visualization system which provides concurrent visual presentation of behavior from all layers, including: the program itself, user-level libraries, the operating system, and the hardware, as this behavior unfolds over time. PV juxtaposes views from different layers in order to facilitate visual correlation, and allows these views to be navigated in a coordinated fashion. This results in an extremely powerful mechanism for exploring application behavior. Experience is presented from actual use of PV in production settings with programmers facing real deadlines and serious performance problems.<<ETX>> | false | false | [
"Doug Kimelman",
"Bryan S. Rosenburg",
"Tova Roth"
] | [] | [] | [] |
Vis | 1,994 | Streamball techniques for flow visualization | 10.1109/VISUAL.1994.346315 | We introduce the concept of streamballs for flow visualization. Streamballs are based upon implicit surface generation techniques adopted from the well-known metaballs. Their property to split or merge automatically in areas of significant divergence or convergence makes them an ideal tool for the visualization of arbitrary complex fields. Using convolution surfaces generated by continuous skeletons for streamball construction offers the possibility to visualize even tensor fields.<<ETX>> | false | false | [
"Manfred Brill",
"Hans Hagen",
"Hans-Christian Rodrian",
"Wladimir Djatschin",
"Stanislav V. Klimenko"
] | [] | [] | [] |
Vis | 1,994 | The design and implementation of the Cortex visualization system | 10.1109/VISUAL.1994.346310 | Cortex has been designed for interactive analysis and display of simulation data generated by CFD applications based on unstructured-grid solvers. Unlike post-processing visualization environments, Cortex is designed to work in co-processing mode with the CFD application. This significantly reduces data storage and data movement requirements for visualization and also allows users to interactively steer the application. Further, Cortex supports high-performance by running on massively parallel computers and workstation clusters. An important goal for Cortex, is to provide visualization to a variety of solvers which differ in their solution methodologies and supported flow models. Coupled with the co-processing requirement, this has required the development of a well defined programming interface to the CFD solver that lets the visualization system communicate efficiently with the solver, and requires minimal programming effort for porting to new solvers. Further, the requirement for targeting multiple solvers and application niches demands that the visualization system be rapidly and easily modifiable. Such flexibility is attained in Cortex by using the high-level, interpreted language Scheme for implementing user-interfaces and high-level visualization functions. By making the Scheme interpreter available from the Cortex text interface, the user can also customize and extend the visualization system.<<ETX>> | false | false | [
"Deb Banerjee",
"Chris Morley",
"Wayne Smith"
] | [] | [] | [] |
Vis | 1,994 | The topology of symmetric, second-order tensor fields | 10.1109/VISUAL.1994.346326 | We study the topology of symmetric, second-order tensor fields. The goal is to represent their complex structure by a simple set of carefully chosen points and lines analogous to vector field topology. We extract topological skeletons of the eigenvector fields, and we track their evolution over time. We study tensor topological transitions and correlate tensor and vector data. The basic constituents of tensor topology are the degenerate points, or points where eigenvalues are equal to each other. Degenerate points play a similar role as critical points in vector fields. We identify two kinds of elementary degenerate points, which we call wedges and trisectors. They can combine to form more familiar singularities-such as saddles, nodes, centers, or foci. However, these are generally unstable structures in tensor fields. Finally, we show a topological rule that puts a constraint on the topology of tensor fields defined across surfaces, extending to tensor fields the Poincare-Hopf theorem for vector fields.<<ETX>> | false | false | [
"Thierry Delmarcelle",
"Lambertus Hesselink"
] | [
"BP"
] | [] | [] |
Vis | 1,994 | Tokamak plasma turbulence visualization | 10.1109/VISUAL.1994.346301 | One of the most fundamental issues in magnetic fusion research is the understanding of turbulent transport observed in present-day tokamak experiments. Plasma turbulence is very challenging from a theoretical point of view due to the nonlinearity and high dimensionality of the governing equations. Recent developments in algorithms along with the astounding advances in high performance computing now make first-principle particle simulations an important tool for improved understanding of such phenomena. Due to the five dimensional phase space (3 spatial, 2 velocity) and complex toroidal geometry, visualization is crucial for interpreting such simulation data. This paper discusses how visualization tools are currently used and what new physics has been elucidated, along with what can be learned about tokamak turbulence through the interplay between theory, simulation and visualization.<<ETX>> | false | false | [
"Scott E. Parker",
"Ravi Samtaney"
] | [] | [] | [] |
Vis | 1,994 | Triangulation and display of rational parametric surfaces | 10.1109/VISUAL.1994.346335 | We present a comprehensive algorithm to construct a topologically correct triangulation of the real affine part of a rational parametric surface with few restrictions on the defining rational functions. The rational functions are allowed to be undefined on domain curves (pole curves) and at certain special points (base points), and the surface is allowed to have nodal or cuspidal self-intersections. We also recognize that for a complete display, some real points on the parametric surface may be generated only by complex parameter values, and that some finite points on the surface may be generated only by infinite parameter values; we show how to compensate for these conditions. Our techniques for handling these problems have applications in scientific visualization, rendering non-standard NURBS, and in finite-element mesh generation.<<ETX>> | false | false | [
"Chandrajit L. Bajaj",
"Andrew V. Royappa"
] | [] | [] | [] |
Vis | 1,994 | UFAT-a particle tracer for time-dependent flow fields | 10.1109/VISUAL.1994.346311 | Time-dependent (unsteady) flow fields are commonly generated in computational fluid dynamics (CFD) simulations; however, there are very few flow visualization systems that generate particle traces in unsteady flow fields. Most existing systems generate particle traces in time-independent flow fields. A particle tracing system has been developed to generate particle traces in unsteady flow fields. The system was used to visualize several 3D unsteady flow fields from real-world problems, and it has provided useful insights into the time-varying phenomena in the flow fields. The design requirements and the architecture of the system are described. Some examples of particle traces computed by the system are also shown.<<ETX>> | false | false | [
"David A. Lane"
] | [] | [] | [] |
Vis | 1,994 | User modeling for adaptive visualization systems | 10.1109/VISUAL.1994.346316 | Meaningful scientific visualizations benefit the interpretation of scientific data, concepts and processes. To ensure meaningful visualizations, the visualization system needs to adapt to desires, disabilities and abilities of the user, interpretation aim, resources (hardware, software) available, and the form and content of the data to be visualized. We suggest describing these characteristics with four models: user model, problem domain/task model, resource model and data model. The paper makes suggestions for the generation of a user model as a basis for an adaptive visualization system. We propose to extract information about the user by involving the user in interactive computer tests and games. Relevant abilities tested are color perception, color memory, color ranking, mental rotation, and fine motor coordination.<<ETX>> | false | false | [
"Gitta Domik",
"Bernd Gutkauf"
] | [] | [] | [] |
Vis | 1,994 | Validation, verification and evaluation | 10.1109/VISUAL.1994.346285 | A discussion is given on the validation, verification and evaluation of scientific visualization software. A "bug" usually refers to software doing something different than the programmer intended. Comprehensive testing, especially for software intended for use in innovative environments, is hard. Descriptions and summaries of the tests we have done are often not available to the users. A different source of visualization errors is software that does something different than what the scientist thinks it does. The particular methods used to compute values in the process of creating visualizations are important to the scientists, but vendors are understandably reluctant to reveal all the internals of their products. Is there a workable compromise? Another vulnerability of visualization users is in the choice of a technique which is less effective than others equally available. Visualization researchers and developers should give users the information required to make good decisions about competing visualization techniques. What information is needed? What will it take to gather and distribute it? How should it be tied to visualization software?.<<ETX>> | false | false | [
"Samuel P. Uselton",
"Geoff Dorn",
"Charbel Farhat",
"Michael W. Vannier",
"Kim H. Esbensen",
"Al Globus"
] | [] | [] | [] |
Vis | 1,994 | Virtual reality performance for virtual geometry | 10.1109/VISUAL.1994.346324 | We describe the theoretical and practical visualization issues solved in the implementation of an interactive real-time four-dimensional geometry interface for the CAVE, an immersive virtual reality environment. While our specific task is to produce a "virtual geometry" experience by approximating physically correct rendering of manifolds embedded in four dimensions, the general principles exploited by our approach reflect requirements common to many immersive virtual reality applications, especially those involving volume rendering. Among the issues we address are the classification of rendering tasks, the specialized hardware support required to attain interactivity, specific techniques required to render 4D objects, and interactive methods appropriate for our 4D virtual world application.<<ETX>> | false | false | [
"Robert A. Cross",
"Andrew J. Hanson"
] | [] | [] | [] |
Vis | 1,994 | Visualization and data analysis in space and atmospheric science | 10.1109/VISUAL.1994.346300 | In this paper we show how SAVS, a tool for visualization and data analysis in space and atmospheric science, can be used to quickly and easily address problems that would previously have been far more laborious to solve. Based on the popular AVS package, SAVS presents the user with an environment tailored specifically for the physical scientist. Thus there is minimal "startup" time, and the scientist can immediately concentrate on his science problem. The SAVS concept readily generalizes to many other fields of science and engineering.<<ETX>> | false | false | [
"A. Mankofsky",
"E. P. Szuszczewicz",
"P. Blanchard",
"C. Goodrich",
"D. McNabb",
"R. Kulkarni",
"D. Kamins"
] | [] | [] | [] |
Vis | 1,994 | Visualization and geographic information system integration: what are the needs and the requirements, if any? | 10.1109/VISUAL.1994.346284 | Addresses the needs and requirements of integrating visualization and geographic information system technologies. There are three levels of integration methods: rudimentary, operational and functional. The rudimentary approach uses the minimum amount of data sharing and exchange between these two technologies. The operational level attempts to provide consistency of the data while removing redundancies between the two technologies. The functional form attempts to provide transparent communication between these respective software environments. At this level, the user only needs to request information and the integrated system retrieves or generates the information depending upon the request. This paper examines the role and impact of these three levels of integration. Stepping further into the future, the paper also questions the long-term survival of these separate disciplines.<<ETX>> | false | false | [
"Theresa-Marie Rhyne",
"William Ivey",
"Loey Knapp",
"Peter Kochevar",
"Tom Mace"
] | [] | [] | [] |
Vis | 1,994 | Visualization in medicine: VIRTUAL reality or ACTUAL reality ? | 10.1109/VISUAL.1994.346288 | Discusses and debates the role played by 3D visualization in medicine as a set of methods and techniques for displaying 3D spatial information related to the anatomy and the physiology of the human body.<<ETX>> | false | false | [
"Christian Roux",
"Jean-Louis Coatrieux",
"Jean-Louis Dillenseger",
"Elliot K. Fishman",
"Murray H. Loew",
"Hans-Peter Meinzer",
"Justin D. Pearlman"
] | [] | [] | [] |
Vis | 1,994 | Visualization of 3D ultrasonic data | 10.1109/VISUAL.1994.346294 | 3D ultrasound is one of the most interesting non-invasive, non-radiative tomographic techniques. Rendering 3D models from such data is not straightforward due to the noisy, fuzzy nature of ultrasound imaging containing a lot of artefacts. We first apply speckle, median and gaussian prefiltering to improve the image quality. Using several semi-automatic segmentation tools we isolate interesting features within a few minutes. Our improved surface-extraction procedure enables volume rendering of high quality within a few seconds on a normal workstation, thus making the complete system suitable for routine clinical applications.<<ETX>> | false | false | [
"Georgios Sakas",
"Lars-Arne Schreyer",
"Marcus Grimm"
] | [
"BCS"
] | [] | [] |
Vis | 1,994 | Visualization of an electric power transmission system | 10.1109/VISUAL.1994.346292 | Visualization techniques are applied to an electric power system transmission network to create a graphical picture of network power flows and voltages. A geographic data map is used. Apparent power flow is encoded as the width of an arrow, with direction from real power flow. Flows are superposed on flow limits. Contour plots and color coding failed for representing bus voltages. A two-color thermometer encoding worked well. The resulting visualization is a significant improvement over current user interface practice in the power industry.<<ETX>> | false | false | [
"Pramod M. Mahadev",
"Richard D. Christie"
] | [] | [] | [] |
Vis | 1,994 | Visualization of mesoscale flow features in ocean basins | 10.1109/VISUAL.1994.346297 | Environmental issues such as global warming are an active area of international research and concern today. This case study describes various visualization paradigms that have been developed and applied in an attempt to elucidate the information provided by environmental models and observations. The ultimate goal is to accurately measure the existence of any long term climatological change. The global ocean is the starting point, since it is a major source and sink of heat within our global environment.<<ETX>> | false | false | [
"Andreas Johannsen",
"Robert J. Moorhead II"
] | [] | [] | [] |
Vis | 1,994 | Visualization of volcanic ash clouds | 10.1109/VISUAL.1994.346290 | Ash clouds resulting from volcanic eruptions are a serious hazard to aviation safety. In Alaska alone, there are over 40 active volcanoes whose eruptions may affect more than 40,000 flights using the great circle polar routes each year. The clouds are especially problematic because they are invisible to radar and nearly impossible to distinguish from weather clouds. The Arctic Region Supercomputing Center and the Alaska Volcano Observatory have collaborated to develop a system for predicting and visualizing the movement of volcanic ash clouds when an eruption occurs. The output from the model is combined with a digital elevation model to produce a realistic view of the ash cloud which may be examined interactively from any desired point of view at any time during the prediction period. This paper describes the visualization techniques employed in the system and includes a video animation of the 1989 Mount Redoubt eruption which caused complete engine failure on a 747 passenger jet.<<ETX>> | false | false | [
"Mitchell Roth",
"Rick Guritz"
] | [] | [] | [] |
Vis | 1,994 | Visualizing 3D velocity fields near contour surfaces | 10.1109/VISUAL.1994.346312 | Vector field rendering is difficult in 3D because the vector icons overlap and hide each other. We propose four different techniques for visualizing vector fields only near surfaces. The first uses motion blurred particles in a thickened region around the surface. The second uses a voxel grid to contain integral curves of the vector field. The third uses many antialiased lines through the surface, and the fourth uses hairs sprouting from the surface and then bending in the direction of the vector field. All the methods use the graphics pipeline, allowing real time rotation and interaction, and the first two methods can animate the texture to move in the flow determined by the velocity field.<<ETX>> | false | false | [
"Nelson L. Max",
"Roger Crawfis",
"Charles Grant"
] | [] | [] | [] |
Vis | 1,994 | Visualizing data: is virtual reality the key? | 10.1109/VISUAL.1994.346286 | A visualization goal is to simplify the analysis of large-quantity, numerical data by rendering the data as an image that can be intuitively manipulated. The question the article addresses is whether or not virtual reality techniques are the cure-all to the dilemma of visualizing increasing amounts of data. It determines the usefulness of techniques available today and in the near future that will ease the problem of visualizing complex data. In regards to visualization, the article discusses characteristics of virtual reality systems, data in three-dimensional environments, augmented reality, and virtual reality market opportunities.<<ETX>> | false | false | [
"Linda M. Stone",
"Thomas Erickson",
"Benjamin B. Bederson",
"Peter Rothman",
"Raymond Muzzy"
] | [] | [] | [] |
Vis | 1,994 | Visualizing flow over curvilinear grid surfaces using line integral convolution | 10.1109/VISUAL.1994.346313 | Line integral convolution (LIC), introduced by B. Cabral and C. Leedom (1993), is a powerful technique for imaging and animating vector fields. We extend the LIC paradigm in three ways: the existing technique is limited to vector fields over a regular Cartesian grid and we extend it to vector fields over parametric surfaces, specifically those found in curvilinear grids, used in computational fluid dynamics simulations; periodic motion filters can be used to animate the flow visualization, but when the flow lies on a parametric surface, the motion appears misleading, and we explain why this problem arises and show how to adjust the LIC algorithm to handle it; we introduce a technique to visualize vector magnitude as well as vector direction, which is based on varying the frequency of the filter function and we develop a different technique based on kernel phase shifts which we have found to show substantially better results. Implementation of these algorithms utilizes texture-mapping hardware to run in real time, which allows them to be included in interactive applications.<<ETX>> | false | false | [
"Lisa K. Forssell"
] | [
"BP"
] | [] | [] |
Vis | 1,994 | Visualizing flow with quaternion frames | 10.1109/VISUAL.1994.346330 | Flow fields, geodesics, and deformed volumes are natural sources of families of space curves that can be characterized by intrinsic geometric properties such as curvature, torsion, and Frenet frames. By expressing a curve's moving Frenet coordinate frame as an equivalent unit quaternion, we reduce the number of components that must be displayed from nine with six constraints to four with one constraint. We can then assign a color to each curve point by dotting its quaternion frame with a 4D light vector, or we can plot the frame values separately as a curve in the three-sphere. As examples, we examine twisted volumes used in topology to construct knots and tangles, a spherical volume deformation known as the Dirac string trick, and streamlines of 3D vector flow fields.<<ETX>> | false | false | [
"Andrew J. Hanson",
"Hui Ma"
] | [] | [] | [] |
Vis | 1,994 | Visualizing multidimensional (multivariate) data and relations | 10.1109/VISUAL.1994.346287 | The paper provides a review of the field of multidimensional data visualisation and discusses some promising methodologies. It considers some crucial problems and directions. The emphasis is more on concepts and foundations rather than ad hoc methods. Visualization is considered as a collection of transformations from problem domains to a perceptual domain, usually visual. The paper discusses the extension of visualisation from the pixel to icons.<<ETX>> | false | false | [
"Alfred Inselberg",
"Georges G. Grinstein",
"Ted Mihalisin",
"Hans Hinterberger"
] | [] | [] | [] |
Vis | 1,994 | Visualizing polycrystalline orientation microstructures with spherical color maps | 10.1109/VISUAL.1994.346338 | Spherical color maps can be an effective tool in the microstructure visualization of polycrystals. Electron backscatter diffraction pattern analysis provides large arrays of the orientation data that can be visualized easily using the technique described in this paper. A combination of this technique with the traditional black and white scanning electron microscopy imaging will enable scientists to better understand the correlation between material properties and their polycrystalline structure.<<ETX>> | false | false | [
"Boris Yamrom",
"John A. Sutliff",
"Andrew P. Woodfield"
] | [] | [] | [] |
Vis | 1,994 | Volume rendering methods for computational fluid dynamics visualization | 10.1109/VISUAL.1994.346314 | The paper describes three alternative volume rendering approaches to visualizing computational fluid dynamics (CFD) data. One new approach uses realistic volumetric gas rendering techniques to produce photo-realistic images and animations from scalar CFD data. The second uses ray casting that is based an a sampler illumination model and is mainly centered around a versatile new tool for the design of transfer functions. The third method employs a simple illumination model and rapid rendering mechanisms to provide efficient preview capabilities. These tools provide a large range of volume rendering capabilities to be used by the CFD explorer to render rapidly for navigation through the data, to emphasize data features (e.g., shock waves) with a specific transfer function, or to present a realistic rendition of the model.<<ETX>> | false | false | [
"David S. Ebert",
"Roni Yagel",
"James N. Scott",
"Yair Kurzion"
] | [] | [] | [] |
Vis | 1,994 | Volume rendering of pool fire data | 10.1109/VISUAL.1994.346291 | We describe how techniques from computer graphics are used to visualize pool fire data and compute radiative effects from pool fires. The basic tools are ray casting and accurate line integration using the RADCAL program. Example images in the visible and infrared band are shown which are given of irradiation calculations and novel methods to visualize the results of irradiation calculations.<<ETX>> | false | false | [
"Holly E. Rushmeier",
"Anthony Hamins",
"Mun-Young Choi"
] | [] | [] | [] |
Vis | 1,994 | VolVis: a diversified volume visualization system | 10.1109/VISUAL.1994.346340 | VolVis is a diversified, easy to use, extensible, high performance, and portable volume visualization system for scientists and engineers as well as for visualization developers and researchers. VolVis accepts as input 3D scalar volumetric data as well as 3D volume-sampled and classical geometric models. Interaction with the data is controlled by a variety of 3D input devices in an input device-independent environment. VolVis output includes navigation preview, static images, and animation sequences. A variety of volume rendering algorithms are supported ranging from fast rough approximations, to compression-domain rendering, to accurate volumetric ray tracing and radiosity, and irregular grid rendering.<<ETX>> | false | false | [
"Ricardo S. Avila",
"Taosong He",
"Lichan Hong",
"Arie E. Kaufman",
"Hanspeter Pfister",
"Cláudio T. Silva",
"Lisa M. Sobierajski",
"Sidney W. Wang"
] | [] | [] | [] |
Vis | 1,994 | Vortex tubes in turbulent flows: identification, representation, reconstruction | 10.1109/VISUAL.1994.346327 | A new algorithm for identifying vortices in complex flows is presented. The scheme uses both the vorticity and pressure fields. A skeleton line along the center of a vortex is produced by a two-step predictor-corrector scheme. The technique uses the vector field to move in the direction of the skeleton line and the scalar field to correct the location in the plane perpendicular to the skeleton line. With an economical description of the vortex tube's cross-section, the skeleton compresses the representation of the flow by a factor of 4000 or more. We show how the reconstructed geometry of vortex tubes can be enhanced to help visualize helical motion.<<ETX>> | false | false | [
"David C. Banks",
"Bart A. Singer"
] | [] | [] | [] |
Vis | 1,994 | Wavelet-based volume morphing | 10.1109/VISUAL.1994.346333 | This paper presents a technique for performing volume morphing between two volumetric datasets in the wavelet domain. The idea is to decompose the volumetric datasets into a set of frequency bands, apply smooth interpolation to each band, and reconstruct to form the morphed model. In addition, a technique for establishing a suitable correspondence among object voxels is presented. The combination of these two techniques results in a smooth transition between the two datasets and produces morphed volume with fewer high frequency distortions than those obtained from spatial domain volume morphing.<<ETX>> | false | false | [
"Taosong He",
"Sidney W. Wang",
"Arie E. Kaufman"
] | [] | [] | [] |
Vis | 1,994 | XmdvTool: integrating multiple methods for visualizing multivariate data | 10.1109/VISUAL.1994.346302 | Much of the attention in visualization research has focussed on data rooted in physical phenomena, which is generally limited to three or four dimensions. However, many sources of data do not share this dimensional restriction. A critical problem in the analysis of such data is providing researchers with tools to gain insights into characteristics of the data, such as anomalies and patterns. Several visualization methods have been developed to address this problem, and each has its strengths and weaknesses. This paper describes a system named XmdvTool which integrates several of the most common methods for projecting multivariate data onto a two-dimensional screen. This integration allows users to explore their data in a variety of formats with ease. A view enhancement mechanism called an N-dimensional brush is also described. The brush allows users to gain insights into spatial relationships over N dimensions by highlighting data which falls within a user-specified subspace.<<ETX>> | false | false | [
"Matthew O. Ward"
] | [] | [] | [] |
CHI | 1,994 | Passive real-world interface props for neurosurgical visualization | 10.1145/191666.191821 | We claim that physical manipulation of familiar real-world objects in the user’s real environment is an important technique for the design of three-dimensional user interfaces. These real-world passive inte~ace props are manipulated by the user to specify spatial relationships between interface objects. By unobtrusively embedding free-space position and orientation trackers within the props, we enable the computer to passively observe a natural user dialog in the real world, rather than forcing the user to engage in a contrived dialog in the computer-generated world. We present neurosurgical planning as a driving application and demonstrate the utility of a head viewing prop, a cutting-plane selection prop, and a trajectory selection prop in this domain. Using passive props in this interface exploits the surgeon’s existing skills, provides direct action-task correspondence, eliminates explicit modes for separate tools, facilitates natural two-handed interaction, and provides tactile and kinesthetic feedback for the user. Our informal evaluation sessions have shown that with a cursory introduction, neurosurgeons who have never seenthe interface can understand and use it without training. | false | false | [
"Ken Hinckley",
"Randy Pausch",
"John C. Goble",
"Neal F. Kassell"
] | [] | [] | [] |
CHI | 1,994 | The cost-of-knowledge characteristic function: display evaluation for direct-walk dynamic information visualizations | 10.1145/191666.191753 | In this paper we present a method, the Cost-of-Knowledge Characteristic Function, for characterizing information access from dynamic displays. The paper works out this method for a simple, but important, class of dynamic displays called direct-walk interactive information visualizations, in which information is accessed through a sequence of mouse selections and key selections. The method is used to characterize a simple calendar task for an application of the Information Visualizer, to compute the changes in characterization as the result of possible program variants, and to conduct empirical comparison between different systems with the same function. | false | false | [
"Stuart K. Card",
"Peter Pirolli",
"Jock D. Mackinlay"
] | [] | [] | [] |
CHI | 1,994 | The movable filter as a user interface tool | 10.1145/191666.191774 | Magic Lens filters are a new user interface tool that combine an arbitrarily-shaped region with an operator that changes the view of objects viewed through that region. These tools can be interactively positioned over on-screen applications much as a magnifying glass is moved over a newspaper. They can be used to help the user understand various types of information, from text documents to scientific visualizations. Because these filters are movable and apply to only part of the screen, they have a number of advantages over traditional windowwide viewing modes: they employ an attractive metaphor based on physical lenses, show a modified view in the context of the original view, limit clutter to a small region, allow easy construction of visual macros and provide a uniform paradigm that can be extended across different types of information and applications. This paper describes these advantages in more detail and illustrates them with examples of magic lens filters in use over a variety of applications. CR | false | false | [
"Maureen C. Stone",
"Kenneth P. Fishkin",
"Eric A. Bier"
] | [] | [] | [] |
CHI | 1,994 | The table lens: merging graphical and symbolic representations in an interactive focus + context visualization for tabular information | 10.1145/191666.191776 | We present a new visualization, called the Table Lens, for visualizing and making sense of large tables. The visualization uses a focus+context (fisheye) technique that works effectively on tabular information because it allows display of crucial label information and multiple distal focal areas. In addition, a graphical mapping scheme for depicting table contents has been developed for the most widespread kind of tables, the cases-by-variables table. The Table Lens fuses symbolic and graphical representations into a single coherent view that can be fluidly adjusted by the user. This fusion and interactivity enables an extremely rich and natural style of direct manipulation exploratory data analysis. | false | false | [
"Ramana Rao",
"Stuart K. Card"
] | [] | [] | [] |
CHI | 1,994 | Using aggregation and dynamic queries for exploring large data sets | 10.1145/191666.191682 | When working with large data sets, users perform three primary types of activities: data manipulation, data analysis, and data visualization. The data manipulation process involves the selection and transformation of data prior to viewing. This paper addresses user goals for this process and the interactive interface mechanisms that support them. We consider three classes of data manipulation goals: controlling the scope (selecting the desired portion of the data), selecting the focus of attention (concentrating on the attributes of data that are relevant to current analysis), and choosing the level of detail (creating and decomposing aggregates of data). We use this classification to evaluate the functionality of existing data exploration interface techniques. Based on these results, we have expanded an interface mechanism called the Aggregate Manipulator (AM) and combined it with Dynamic Query (DQ) to provide complete coverage of the data manipulation goals. We use real estate sales data to demonstrate how the AM and DQ synergistically function in our interface. | false | false | [
"Jade Goldstein",
"Steven F. Roth"
] | [] | [] | [] |
Vis | 1,993 | 3D simulation of delivery | 10.1109/VISUAL.1993.398903 | We show how to create 3D models of maternal pelvis and fetal head from magnetic resonance images (MRI). The models are used to simulate the progress of delivery in order to give a prognosis of successful labor.<<ETX>> | false | false | [
"Jean-Daniel Boissonnat",
"Bernhard Geiger"
] | [] | [] | [] |
Vis | 1,993 | A climate simulation case study | 10.1109/VISUAL.1993.398900 | A supercomputing-visualization facility for science and engineering applications was used for processing and visualizing supercomputer-generated data. This facility includes a vector-processing supercomputer, a graphics workstation, a general purpose workstation, a high-resolution color printer, a scanner, a film recorder, a video tape recorder, and a video laser disc recorder. The facility is using a network system to connect computers, workstations, and graphical input/output devices. The supercomputer generates time-dependent multivariate data using a global climate simulation model. Visualization software systems are used for visualizing these model-produced data. Visualization techniques including: iso-contouring, iso-surface generation, vectors and streamlines generation are used.<<ETX>> | false | false | [
"P. C. Chen"
] | [] | [] | [] |
Vis | 1,993 | A probe for local flow field visualization | 10.1109/VISUAL.1993.398849 | A probe for the interactive visualization of flow fields is presented. The probe can be used to visualize many characteristics of the flow in detail for a small region in the data set. The velocity and the local change of velocity (the velocity gradient tensor) are visualized by a set of geometric primitives. To this end, the velocity gradient tensor is transformed to a local coordinate frame, and decomposed into components parallel with and perpendicular to the flow. These components are visualized as geometric objects with an intuitively meaningful interpretation. An implementation is presented which shows that this probe is a useful tool for flow visualization.<<ETX>> | false | false | [
"Wim C. de Leeuw",
"Jarke J. van Wijk"
] | [] | [] | [] |
Vis | 1,993 | Accelerating volume animation by space-leaping | 10.1109/VISUAL.1993.398852 | In this work we present a method for speeding the process of volume animation. It exploits coherency between consecutive images to shorten the path rays take through the volume. Rays are provided with the information needed to leap over the empty space and commence volume traversal at the vicinity of meaningful data. The algorithm starts by projecting the volume onto a C-buffer (coordinates-buffer) which stores the object-space coordinates of the first non-empty voxel visible from a pixel. Following a change in the viewing parameters, the C-buffer is transformed accordingly. Next, coordinates that possibly became hidden are discarded. The remaining values serve as an estimate of the point where the new rays should start their volume traversal. This method does not require 3-D preprocessing and does not suffer from any image degradation. It can be combined with existing acceleration techniques and can support any ray traversal algorithm and material modeling scheme.<<ETX>> | false | false | [
"Roni Yagel",
"Zhouhong Shi"
] | [] | [] | [] |
Vis | 1,993 | An architecture for rule-based visualization | 10.1109/VISUAL.1993.398874 | In Rogowitz and Treinish (1993), we introduced an architecture for incorporating perceptual rules into the visualization process. In this architecture, higher-level descriptors of the data, metadata, flow to perceptual rules, which constrain visualization operations. In this paper, we develop a deeper analysis of the rules, the prerequisite metadata, and the system for enabling their operation.<<ETX>> | false | false | [
"Bernice E. Rogowitz",
"Lloyd Treinish"
] | [] | [] | [] |
Vis | 1,993 | An environment for telecollaborative data exploration | 10.1109/VISUAL.1993.398858 | This paper presents an environment for telecollaborative data exploration. It provides the following capabilities essential to data exploration: (1) users can probe the data, defining regions of interest with arbitrary shapes. (2) The selected data can be transformed and displayed in many different ways. (3) Linked cursors can be established between several windows showing data sets with arbitrary relationships. (4) Data can be displayed on any screen across a computer network, allowing for telecollaboration arrangements with linked cursors around the world. (5) Our system is user-extensible, allowing programmers to change any component of it while keeping the remaining functionality. We demonstrate how the system can be used in several applications, such as biomedical imaging, robotics, and wood classification.<<ETX>> | false | false | [
"Gudrun Klinker"
] | [] | [] | [] |
Vis | 1,993 | Applying observations of work activity in designing prototype data analysis tools | 10.1109/VISUAL.1993.398873 | Designers, implementers, and marketers of data analysis tools typically have different perspectives than end users. Consequently, data analysts often find themselves using tools focused on graphics and programming concepts rather than concepts which reflect their own domain and the context of their work. Some user studies focus on usability tests late in development; others observe work activity, but fail to show how to apply that knowledge in design. This paper describes a methodology for applying observations of data analysis work activity in prototype tool design. The approach can be used both in designing improved data analysis tools, and customizing visualization environments to specific applications. We present an example of user-centered design for a prototype tool to cull large data sets. We revisit the typical graphical approach of animating a large data set from the point of view of an analyst who is culling data. Field evaluations using the prototype tool not only revealed valuable usability information, but initiated in-depth discussions about user's work, tools, technology, and requirements.<<ETX>> | false | false | [
"R. R. Springmeyer"
] | [] | [] | [] |
Vis | 1,993 | Bridging the gap between visualization and data management: A simple visualization management system | 10.1109/VISUAL.1993.398856 | A prototype visualization management system is described which merges the capabilities of a database management system with any number of existing visualization packages such as AVS or IDL. The prototype uses the Postgres database management system to store and access Earth science data through a simple graphical browser. Data located in the database is visualized by automatically invoking a desired visualization package and downloading an appropriate script or program. The central idea underlying the system is that information on how to visualize a data set is stored in the database with the data set itself.<<ETX>> | false | false | [
"Peter Kochevar",
"Zahid Ahmed",
"J. Shade",
"Colin Sharp"
] | [] | [] | [] |
Vis | 1,993 | Cloud tracing in convection-diffusion systems | 10.1109/VISUAL.1993.398876 | The paper describes a highly interactive method for computer visualization of simultaneous three-dimensional vector and scalar flow fields in convection-diffusion systems. This method allows a computational fluid dynamics user to visualize the basic physical process of dispersion and mixing rather than just the vector and scalar values computed by the simulation. It is based on transforming the vector field from a traditionally Eulerian reference frame into a Lagrangian reference frame. Fluid elements are traced through the vector field for the mean path as well as the statistical dispersion of the fluid elements about the mean position by using added scalar information about the root mean square value of the vector field and its Lagrangian time scale. In this way, clouds of fluid elements are traced not just mean paths. We have used this method to visualize the simulation of an industrial incinerator to help identify mechanisms for poor mixing.<<ETX>> | false | false | [
"Kwan-Liu Ma",
"Philip J. Smith"
] | [] | [] | [] |
Vis | 1,993 | Computer visualization of long genomic sequences | 10.1109/VISUAL.1993.398883 | Human beings find it difficult to analyze local and global oligonucleotide patterns in the linear primary sequences of a genome. In this paper, we present a family of iterated function systems (IFS) that can be used to generate a set of visual models of a DNA sequence. A new visualization function, the W-curve, that is derived from this IFS family is introduced. Using W-curves, a user can readily compare subsequences within a long genomic sequence - or between genomic sequences - and can visually evaluate the effect of local variations (mutations) upon the global genomic information content.<<ETX>> | false | false | [
"Dachywan Wu",
"James Robergé",
"Douglas J. Cork",
"Bao Gia Nguyen",
"Thom Grace"
] | [] | [] | [] |
Vis | 1,993 | Data shaders | 10.1109/VISUAL.1993.398879 | The process of visualizing a scientific data set requires an extensive knowledge of the domain in which the data set is created. Because an in-depth knowledge of all scientific domains is not available to the creator of visualization software, a flexible and extensible visualization system is essential in providing a productive tool to the scientist. This paper presents a shading language, based on the RenderMan shading language, that extends the shading model used to render volume data sets. Data shaders, written in this shading language, give the users of a volume rendering system a means of specifying how a volume data set is to be rendered. This flexibility is useful both as a visualization tool in the scientific community and as a research tool in the visualization community.<<ETX>> | false | false | [
"Brian Corrie",
"Paul Mackerras"
] | [] | [] | [] |
Vis | 1,993 | Developing modular application builders to exploit MIMD parallel | 10.1109/VISUAL.1993.398861 | Modular application builders (MABs), such as AVS and Iris Explorer are increasingly being used in the visualization community. Such systems can already place compute intensive modules on supercomputers in order to utilize their power. This paper details two major projects at EPCC which attempted to fully integrate the MAB concept with a distributed memory MIMD (DM-MIMD) environment. The work presented was driven by two goals, efficient use of the resource and case of use by programmer and end user. We present a model of MABs and describe the major problems faced, giving solutions to them through two case studies.<<ETX>> | false | false | [
"C. Thornborrow",
"A. J. S. Wilson",
"Chris Faigle"
] | [] | [] | [] |
Vis | 1,993 | Dichromatic color representations for complex display systems | 10.1109/VISUAL.1993.398871 | New display technologies have begun to provide more innovative and potentially powerful methods to present information to a viewer. However, many of these techniques struggle to deliver accurate full color. In this paper, we address this difficulty by employing the dichromatic theory of color reflection, which implies that many objects can be rendered accurately using only two primaries. Complex display systems with two primaries can be produced with significantly less work than is required for the traditional three primaries. We discuss methods for selecting objects that can be rendered accurately on two-color displays, and we present our experiments with a two-color display using monochromatic primaries.<<ETX>> | false | false | [
"Mark S. Peercy",
"Lambertus Hesselink"
] | [] | [] | [] |
Vis | 1,993 | DIVIDE: Distributed visual display of the execution of asynchronous, distributed algorithms on loosely-coupled parallel processors | 10.1109/VISUAL.1993.398865 | The issue of monitoring the execution of asynchronous, distributed algorithms on loosely-coupled parallel processor systems, is important for the purposes of (i) detecting inconsistencies and flaws in the algorithm, (ii) obtaining important performance parameters for the algorithm, and (iii) developing a conceptual understanding of the algorithm's behavior, for given input stimulus, through visualization. For a particular class of asynchronous distributed algorithms that may be characterized by independent and concurrent entities that execute asynchronously on multiple processors and interact with one another through explicit messages, the following reasoning applies. Information about the flow of messages and the activity of the processors may contribute significantly towards the conceptual understanding of the algorithm's behavior and the functional correctness of the implementation. The computation and subsequent display of important parameters, based upon the execution of the algorithm, is an important objective of DIVIDE. For instance, the mean and standard deviation values for the propagation delay of ATM cells between any two given Broadband-ISDN (BISDN) nodes in a simulation of BISDN network under stochastic input stimulus, as a function of time, are important clues to the degree of congestion in the Broadband-ISDN network. Although the execution of the algorithm typically generates high resolution data, often, a coarse-level visual representation of the data may be useful in facilitating the conceptual understanding of the behavior of the algorithm. DIVIDE permits a user to specify a resolution less than that of the data from the execution of the algorithm, which is then utilized to coalesce the data appropriately. Given that this process requires significant computational power, for efficiency, DIVIDE distributes the overall task of visual display into a number of user specified workstations that are configured as a loosely-coupled parallel processor. DIVIDE has been implemented on a heterogeneous network of SUN sparc 1 + , sparc 2, and 3/60 workstations and performance measurements indicate significant improvement over that of a uniprocessor-based visual display.<<ETX>> | false | false | [
"Tom M. Morrow",
"Sumit Ghosh"
] | [] | [] | [] |
Vis | 1,993 | Enhancing reality in the operating room | 10.1109/VISUAL.1993.398902 | Three dimensional computer models of the anatomy generated from volume acquisitions of computed tomography and magnetic resonance imaging are useful adjuncts to 2D images. This paper describes a system that merges the computer generated 3D models with live video to enhance the surgeon's understanding of the anatomy beneath the surface. The system can be used as a planning aid before the operation and provide additional information during an operation. The application of the system to a brain operation is described.<<ETX>> | false | false | [
"William E. Lorensen",
"Harvey E. Cline",
"Christopher Nafis",
"Ron Kikinis",
"David Altobelli",
"P. Langham Gleason"
] | [
"BCS"
] | [] | [] |
Vis | 1,993 | Fanal: A relational analysis and visualization package for high energy physics | 10.1109/VISUAL.1993.398897 | The package described in this paper has been designed for analyzing the data collected in the LEP experiment ALEPH. Its main graphical feature is a deep interplay between the description of the objects manipulated and their relationships, and their graphical representation. The easy access to information through navigation between objects and its display makes possible a thorough study of the events produced by the detector. This has proved to be very powerful in numerous occasions for analyzing data and testing programs. The package provides as well statistical analysis tools and a graphic editor. It is based on the PHIGS graphics standard. It will develop towards a more elaborate usage of the data structure in particular in the geometrical representations and towards object oriented languages to overcome some heaviness linked to the use of Fortran.<<ETX>> | false | false | [
"H. Videau",
"P. Mora de Freitas"
] | [] | [] | [] |
Vis | 1,993 | Fast analytical computation of Richard's smooth molecular surface | 10.1109/VISUAL.1993.398882 | An algorithm for rapid computation of Richards's smooth molecular surface is described. The entire surface is computed analytically, triangulated, and displayed at interactive rates. The faster speeds for our program have been achieved by algorithmic improvements, paralleling the computations, and by taking advantage of the special geometrical properties of such surfaces. Our algorithm is easily parallelable and it has a time complexity of O (k log k) over n processors, where n is the number of atoms of the molecule and k is the average number of neighbors per atom.<<ETX>> | false | false | [
"Amitabh Varshney",
"Frederick P. Brooks Jr."
] | [] | [] | [] |
Vis | 1,993 | Fast volume rendering of compressed data | 10.1109/VISUAL.1993.398845 | Volume rendering has been proposed as a useful tool for extracting information from large datasets, where non-visual analysis alone may not be feasible. The scale of these applications implies that data management is an important issue that needs to be addressed. Most volume rendering algorithms, however, process data in raw, uncompressed form. In previous work, we introduced a compressed volume format that may be volume rendered directly with minimal impact on rendering time. In this paper, we extend these ideas to a new volume format that not only reduces storage space and transmission time, but is designed for fast volume rendering as well. The volume dataset is represented as indices into a small codebook of representative blocks. With the data structure, volume shading calculations need only be performed on the codebook and image generation is accelerated by reusing precomputed block projections.<<ETX>> | false | false | [
"Paul Ning",
"Lambertus Hesselink"
] | [] | [] | [] |
Vis | 1,993 | Feature extraction for oceanographic data using a 3D edge operator | 10.1109/VISUAL.1993.398901 | The features of greatest interest in ocean modeling in the Gulf of Mexico and along the Gulf Stream are the fronts and eddies. Resolving, modeling, and tracking these eddies over time is of great importance for climatological studies and economic advancement. In this paper we present a novel technique for automatically locating, contouring, and tracking oceanic features such as eddies and fronts. The models and resultant visualizations exhibit excellent correlation with observed data.<<ETX>> | false | false | [
"R. J. Moorehead",
"Z. Zhu"
] | [] | [] | [] |
Vis | 1,993 | Fine-grain visualization algorithms in dataflow environments | 10.1109/VISUAL.1993.398860 | Most of the current dataflow visualization systems are based on coarse-grain dataflow computing models. In this paper we propose a fine-grain dataflow model that takes advantage of data locality properties of many visualization algorithms. A fine-grain module works on small chunks of data one at a time by keeping a dynamically adjusted moving window on the input data stream. It is more memory efficient and has the potential of handling very large data sets without taking up all the memory resources. Two popular visualization algorithms, an iso-surface extraction algorithm and a volume rendering algorithm, are implemented using the fine-grain model. The performance measurements showed faster speed, reduced memory usage, and improved CPU utilization over a typical coarse-grain system.<<ETX>> | false | false | [
"D. Song",
"Eric J. Golin"
] | [] | [] | [] |
Vis | 1,993 | Flow volumes for interactive vector field visualization | 10.1109/VISUAL.1993.398846 | Flow volumes are the volumetric equivalent of stream lines. They provide more information about the vector field being visualized than do stream lines or ribbons. Presented is an efficient method for producing flow volumes, composed of transparently rendered tetrahedra, for use in an interactive system. The problems of rendering, subdivision, sorting, composing artifacts, and user interaction are dealt with. Efficiency comes from rendering only the volume of the smoke, and using hardware texturing and compositing.<<ETX>> | false | false | [
"Nelson L. Max",
"Barry G. Becker",
"Roger Crawfis"
] | [] | [] | [] |
Vis | 1,993 | Geometric clipping using Boolean textures | 10.1109/VISUAL.1993.398878 | Texture mapping is normally used to convey geometric detail without adding geometric complexity. This paper introduces Boolean textures, a texture mapping technique that uses implicit functions to generate texture maps and texture coordinates. These Boolean textures perform clipping during a renderer's scan conversion step. Any implicit function is a candidate Boolean texture clipper. The paper describes how to use quadrics as clippers. Applications from engineering and medicine illustrate the effectiveness of texture as a clipping tool.<<ETX>> | false | false | [
"William E. Lorenson"
] | [
"BP"
] | [] | [] |
Vis | 1,993 | Geometric optimization | 10.1109/VISUAL.1993.398868 | An algorithm is presented which describes an application independent method for reducing the number of polygonal primitives required to faithfully represent an object. Reducing polygon count without a corresponding reduction in object detail is important for: achieving interactive frame rates in scientific visualization, reducing mass storage requirements, and facilitating the transmission of large, multi-timestep geometric data sets. This paper shows how coplanar and nearly coplanar polygons can be merged into larger complex polygons and re-triangulated into fewer simple polygons than originally required. The notable contributions of this paper are: (1) a method for quickly grouping polygons into nearly coplanar sets, (2) a fast approach for merging coplanar polygon sets and, (3) a simple, robust triangulation method for polygons created by 1 and 2. The central idea of the algorithm is the notion of treating polygonal data as a collection of segments and removing redundant segments to quickly form polygon hulls which represent the merged coplanar sets.<<ETX>> | false | false | [
"Paul A. Hinker",
"Charles D. Hansen"
] | [] | [] | [] |
Vis | 1,993 | GRASPARC-A problem solving environment integrating computation and visualization | 10.1109/VISUAL.1993.398857 | Visualization has proved an efficient tool in the understanding of large data sets in computational science and engineering. There is growing interest today in the development of problem solving environments which integrate both visualization and the computational process which generates the data. The GRASPARC project has looked at some of the issues involved in creating such an environment. An architecture is proposed in which tools for computation and visualization can be embedded in a framework which assists in the management of the problem solving process. This framework has an integral data management facility which allows an audit trail of the experiments to be recorded. This design therefore allows not only steering but also backtracking and more complicated problem solving strategies. A number of demonstrator case studies have been implemented.<<ETX>> | false | false | [
"Ken Brodlie",
"Andrew Poon",
"Helen Wright",
"Lesley Brankin",
"Greg Banecki",
"Alan Gay"
] | [] | [] | [] |
Vis | 1,993 | HyperSlice - Visualization of Scalar Functions of Many Variables | 10.1109/VISUAL.1993.398859 | HyperSlice is a new method for the visualization of scalar functions of many variables. With this method the multi-dimensional function is presented in a simple and easy to understand way in which all dimensions are treated identically. The central concept is the representation of a multi-dimensional function as a matrix of orthogonal two-dimensional slices. These two-dimensional slices lend themselves very well to interaction via direct manipulation, due to a one to one relation between screen space and variable space. Several interaction techniques, for navigation, the location of maxima, and the use of user-defined paths, are presented.<<ETX>> | false | false | [
"Jarke J. van Wijk",
"Robert van Liere"
] | [] | [] | [] |
Vis | 1,993 | Implicit stream surfaces | 10.1109/VISUAL.1993.398875 | Streamlines and stream surfaces are well known techniques for the visualization of fluid flow. For steady velocity fields, a streamline is the trace of a particle, and a stream surface is the trace of a curve. Here a new method is presented for the construction of stream surfaces. The central concept is the representation of a stream surface as an implicit surface f (x) = C. After the initial calculation of f a family of stream surfaces can be generated efficiently by varying C. The shapes of the originating curves are defined by the value of f at the boundary. Two techniques are presented for the calculation of f: one based on solving the convection equation, the other on backward tracing of the trajectories of grid points. The flow around objects is discussed separately. With this method irregular topologies of the originating curves and of the stream surfaces can be handled easily. Further, it can also be used for other visualization techniques, such as time surfaces and stream volumes. Finally, an effective method for the automatic placement of originating curves is presented.<<ETX>> | false | false | [
"Jarke J. van Wijk"
] | [] | [] | [] |
Vis | 1,993 | InfoCrystal: A visual tool for information retrieval | 10.1109/VISUAL.1993.398863 | This paper introduces a novel representation, called the InfoCrystal, that can be used as a visualization tool as well as a visual query language to help users search for information. The InfoCrystal visualizes all the possible relationships among N concepts. Users can assign relevance weights to the concepts and use thresholding to select relationships of interest. The InfoCrystal allows users to specify Boolean as well as vector-space queries graphically. Arbitrarily complex queries can be created by using the InfoCrystals as building blocks and organizing them in a hierarchical structure. The InfoCrystal enables users to explore and filter information in a flexible, dynamic and interactive way.<<ETX>> | false | false | [
"Anselm Spoerri"
] | [] | [] | [] |
Vis | 1,993 | Interactive shading for surface and volume visualization on graphics workstations | 10.1109/VISUAL.1993.398881 | Shading is an effective exploratory visualization tool widely used in scientific visualization. Interactive, or close to interactive, shading of images offers significant benefit, but is generally too computationally expensive for graphics workstations. A novel method for providing interactive diffuse and specular shading capability on low-cost graphics workstations is described. Application to digital elevation models, iso-surfaces in volumetric images, and color-coded aspect maps are illustrated and an analysis of artifacts, and of ways of minimizing artifacts, is given.<<ETX>> | false | false | [
"Peter A. Fletcher",
"Philip K. Robertson"
] | [] | [] | [] |
Vis | 1,993 | Interactive visualization methods for four dimensions | 10.1109/VISUAL.1993.398869 | Making accurate computer graphics representations of surfaces and volumes (2-manifolds and 3-manifolds) embedded in four-dimensional space typically involves complex and time-consuming computations. In order to make simulated worlds that help develop human intuition about the fourth dimensions, we need techniques that permit real-time, interactive manipulation of the most sophisticated depictions available. We propose the following new methods that bring us significantly closer to this goal: an approach to high-speed 4D illuminated surface rendering incorporating 4D shading and occlusion coding; a procedure for rapidly generating 2D screen images of tessellated 3-manifolds illuminated by 4D light. These methods are orders of magnitude faster than previous approaches, enabling the real-time manipulation of high-resolution 4D images on commercial graphics hardware.<<ETX>> | false | false | [
"Andrew J. Hanson",
"Robert A. Cross"
] | [] | [] | [] |
Vis | 1,993 | MRIVIEW: An interactive computational tool for investigation of brain structure and function | 10.1109/VISUAL.1993.398885 | MRIVIEW is a software system that uses image processing and visualization to provide neuroscience researchers with an integrated environment for combining functional and anatomical information. Key features of the software include semi-automated segmentation of volumetric head data and an interactive coordinate reconciliation method which utilizes surface visualization. The current system is a precursor to a computational brain atlas. We describe features this atlas will incorporate, including methods under development for visualizing brain functional data obtained from several different research modalities.<<ETX>> | false | false | [
"Douglas M. Ranken",
"John S. George"
] | [] | [] | [] |
Vis | 1,993 | Navigating large networks with hierarchies | 10.1109/VISUAL.1993.398870 | This paper is aimed at the exploratory visualization of networks where there is a strength or weight associated with each link, and makes use of any hierarchy present on the nodes to aid the investigation of large networks. It describes a method of placing nodes on the plane that gives meaning to their relative positions. The paper discusses how linking and interaction principles aid the user in the exploration. Two examples are given; one of electronic mail communication over eight months within a department, another concerned with changes to a large section of a computer program.<<ETX>> | false | false | [
"Stephen G. Eick",
"Graham J. Wills"
] | [] | [] | [] |
Vis | 1,993 | Non conventional methods for the visualization of events from high energy physics | 10.1109/VISUAL.1993.398898 | Visualization of events in high energy physics is an important tool to check hard- and software and to generate pictures for presentation purposes. The radial pattern of all events suggests the use of predefined projections, especially p/Z and Y/X. The representation can be improved by a "fish-eye" transformation and by angular projections, which produce straight track patterns and allow extensive magnifications. Three dimensional data of radial structure are best displayed in the 3D V-Plot, which has optimal track separation and presents all relevant information in a clear way.<<ETX>> | false | false | [
"Hans Drevermann",
"D. Kuhm",
"B. Nilsson"
] | [] | [] | [] |
Vis | 1,993 | Optimal filter design for volume reconstruction and visualization | 10.1109/VISUAL.1993.398851 | Digital filtering is a crucial operation in volume reconstruction and visualization. Lowpass filters are needed for subsampling and minification. Interpolation filters are needed for registration and magnification, and to compensate for geometric distortions introduced by scanners. Interpolation filters are also needed in volume rendering for ray-casting and slicing. In this paper, we describe a method for digital filter design of interpolation filters based on weighted Chebyshev minimization. The accuracy of the resulting filters are compared with some commonly used filters defined by piecewise cubic polynomials. A significant finding of this paper is that although piecewise cubic interpolation has some computational advantages and may yield visually satisfactory results for some data, other data result in artifacts such as blurring. Furthermore, piecewise cubic filters are inferior for operations such as registration. Better results are obtained by the filters derived in this papers at only small increases in computation.<<ETX>> | false | false | [
"Ingrid Carlbom"
] | [] | [] | [] |
Vis | 1,993 | Orientation maps: Techniques for visualizing rotations (A Consumer's Guide) | 10.1109/VISUAL.1993.398867 | The set of possible orientations of a rigid three-dimensional object is a topological space with three degrees of freedom. This paper investigates the suitability of various techniques of visualizing this space. With a good technique the natural distance between orientations will be represented fairly accurately, and distortion to the "shape" of a collection of orientations induced by the change of reference orientation will be minor. The traditional Euler-angle parameterization fails on both counts. Less well-known techniques exploit the fact that there is a rotation that takes the reference orientation to a given one. The given orientation is represented as a point along the axis of this rotation. The distance of this point from the origin is determined by some scaling function of the magnitude of that rotation. Free natural scaling functions are studied. None is perfect, but several are satisfactory.<<ETX>> | false | false | [
"Bowen Alpern",
"Larry Carter",
"Matt Grayson",
"Chris Pelkie"
] | [] | [] | [] |
Vis | 1,993 | Performance visualization of parallel programs | 10.1109/VISUAL.1993.398866 | The user of a parallel computer system would like to know the performance of a program in terms of how optimally it uses the system resources. This task is increasingly performed by program performance visualization. The limitations of conventional performance data analysis techniques necessitate better visual analysis methods that are scalable with the problem and system sizes and extensible. They should represent some physical and logical structure of the parallel system and program. The analysis techniques presented here have been motivated by the use of signal and (two- and three-dimensional) image processing techniques being applied in some areas of scientific visualization. Results of applying selected techniques are shown. These techniques and tools have advantages and disadvantages when applied in this area.<<ETX>> | false | false | [
"Abdul Waheed",
"Diane T. Rover"
] | [] | [] | [] |
Vis | 1,993 | Rapid exploration of curvilinear grids using direct volume rendering (Extended Abstract) | 10.1109/VISUAL.1993.398853 | Fast techniques for direct volume rendering over curvilinear grids (common to computational fluid dynamics and finite element analysis) are developed. Three new projection methods that use polygon-rendering hardware for speed are presented and compared with each other and with previous methods for tetrahedral grids and rectilinear grids. A simplified algorithm for visibility ordering, based on a combination of breadth-first and depth-first searches, is described. A new multi-pass blending method is described that reduces visual artifacts that are introduced by linear interpolation in hardware where exponential interpolation is needed. Visualization tools that permit rapid data banding and cycling through transfer functions, as well as region restriction, are described.<<ETX>> | false | false | [
"Allen Van Gelder",
"Jane Wilhelms"
] | [] | [] | [] |
Vis | 1,993 | Spray rendering: Visualization using smart particles | 10.1109/VISUAL.1993.398880 | We propose a new framework for doing scientific visualization. The basis for this framework is a combination of particle systems and behavioral animation. Here, particles are not only affected by the field that they are in, but can also exhibit different programmed behaviors. An intuitive delivery system, based on virtual cans of spray paint, is also described to introduce the smart particles into the data set. Hence the name spray rendering. Using this metaphor, different types of spray paint are used to highlight different features in the data set. Spray rendering offers several advantages over existing methods: (1) it generalizes the current techniques of surface, volume and flow visualization under one coherent framework; (2) it works with regular and irregular grids as well as sparse and dense data sets; (3) it allows selective progressive refinement; (4) it is modular, extensible and provides scientists with the flexibility for exploring relationships in their data sets in natural and artistic ways.<<ETX>> | false | false | [
"Alex T. Pang",
"Kyle Smith"
] | [] | [] | [] |
Vis | 1,993 | Texture splats for 3D scalar and vector field visualization | 10.1109/VISUAL.1993.398877 | Volume visualization is becoming an important tool for understanding large 3D data sets. A popular technique for volume rendering is known as splatting. With new hardware architectures offering substantial improvements in the performance of rendering texture mapped objects, we present textured splats. An ideal reconstruction function for 3D signals is developed which can be used as a texture map for a splat. Extensions to the basic splatting technique are then developed to additionally represent vector fields.<<ETX>> | false | false | [
"Roger Crawfis",
"Nelson L. Max"
] | [
"TT",
"BP"
] | [] | [] |
Vis | 1,993 | The quantum Coulomb three-body problem - Visualization of simulation results and numerical methods | 10.1109/VISUAL.1993.398911 | Some years ago it was established that the muon catalyzed fusion phenomenon could be used for the production of energy. This fact has been causing a rebirth of interest in the universal methods of solving the quantum Coulomb three-body problem. The adiabatic hyperspherical (AHS) approach considered in this joint project has definite advantages in comparison with other methods. The case study proposed focuses on the study of the structure and behavior of the wave function of bound states of a quantum three-body system as well as of the basis functions of the AHS approach. Adapted scientific visualization tools such as surface rendering, volume ray tracing and texturing will be used. Visualization allows to discover interesting features in the behavior of the basis functions and to analyze the convergence of the AHS-expansion for the wave functions.<<ETX>> | false | false | [
"D. I. Abramov",
"V. V. Gusev",
"Stanislav V. Klimenko",
"L. I. Ponomarev",
"W. Krueger",
"W. Renz"
] | [] | [] | [] |
Vis | 1,993 | The virtual restoration of the Visir tomb | 10.1109/VISUAL.1993.398904 | In the field of computer applications to archaeology, data visualization is one of the most recent and promising activity. The visual reconstruction obtained from partially or totally ruined data is a problem that archaeologists often face with during their work. The case we present here is the simulated reconstruction of a great Egyptian tomb of the VII century B.C. excavated in the rocky cliff of the desert. The visualization method is fundamental for testing the hypotheses made and as a strategic solution in the concrete reconstruction. The hundreds of magnificent decorated blocks saved by museums will never be positioned again on its walls. Moreover, in front of the stress and pollution caused to ancient monuments by a massive tourism, the ever-growing improving of visualization and animation techniques, like the ones presented in this paper, makes of considerable interest the modeling and the exploration inside the virtual monuments through realistic tours.<<ETX>> | false | false | [
"Patrizia Palamidese",
"M. Betro",
"G. Muccioli"
] | [] | [] | [] |
Vis | 1,993 | The vision camera: An interactive tool for volume data exploration and navigation | 10.1109/VISUAL.1993.398847 | In this work we focus on one of the key problems of scientific visualization, the object recognition dilemma. The necessity to pre-interpret application data in order to classify object surface voxels prior to rendering has prevented many visualization methods from becoming practical. We propose the concept of vision by visualization which integrates computer vision methods into the visualization process. Based on this, we present the vision camera, a new tool allowing for interactive object recognition during volume data walkthroughs. This camera model is characterized by a flexible front-plane which, under the control of user-specified parameters and image features elastically matches to object surfaces, while shifted through a data volume. Thus, objects are interactively carved out and can be visualized by standard volume visualization methods. Implementation and application of the model are described. Our results suggest that by the integration of human and machine vision new perspectives for data exploration are opened up.<<ETX>> | false | false | [
"Hans-Heino Ehricke",
"Gerhard Daiber",
"Wolfgang Straßer"
] | [] | [] | [] |
Vis | 1,993 | Tioga: A database-oriented visualization tool | 10.1109/VISUAL.1993.398855 | In the work we present a new architecture for visualization systems that is based on data base management system (DBMS) technology. By building on the mechanisms present in a next-generation DBMS, rather than merely on the capabilities of a standard file manager, we show that a simpler and more powerful visualization system can be constructed. We retain the popular "boxes and arrows" programming notation for constructing visualization programs, but add a "flight simulator" model of movement to navigate the output of such programs. In addition, we provide a means to specify a hierarchy of abstracts of data of different types and resolutions, so that a "zoom" capability can be supported. The underlying DBMS support for this system, Tioga, is briefly described, as well as the current state of the implementation.<<ETX>> | false | false | [
"Michael Stonebraker",
"Jolly Chen",
"Nobuko Nathan",
"Caroline Paxson",
"Alan Su",
"Jiang Wu"
] | [] | [] | [] |
Vis | 1,993 | Towards a texture naming system: Identifying relevant dimensions of texture | 10.1109/VISUAL.1993.398872 | Recently, researchers have started using texture for data visualization. The rationale behind this is to exploit the sensitivity of the human visual system to texture in order to overcome the limitations inherent in the display of multidimensional data. A fundamental issue that must be addressed is what textural features are important in texture perception, and how they are used. We designed an experiment to help identify the relevant higher order features of texture perceived by humans. We used twenty subjects, who were asked to rate 56 pictures from Brodatz's album on 12 nine-point Likert scales. We applied the techniques of hierarchical cluster analysis, non-parametric multidimensional scaling (MDS), classification and regression tree analysis (CART), discriminant analysis, and principal component analysis to data gathered from the subjects. Based on these techniques, we identified three orthogonal dimensions for texture to be repetitive vs. non-repetitive; high-contrast and non-directional vs. low-contrast and directional; granular, coarse and low-complexity vs. non-granular, fine and high-complexity.<<ETX>> | false | false | [
"A. Ravishankar Rao",
"Gerald L. Lohse"
] | [] | [] | [] |
Vis | 1,993 | Towards interactive steering, visualization and animation of unsteady finite element simulations | 10.1109/VISUAL.1993.398895 | Progress towards interactive steering of the time-accurate, unsteady finite-element simulation program DYNA3D is reported. Rudimentary steering has been demonstrated in a distributed computational environment encompassing a supercomputer, multiple graphics workstations, and a single frame animation recorder. The coroutine facility of AVS (application visualization system from AVS Inc.) and software produced in-house has been coordinated to prove the concept. This work also applies to other large batch-oriented FORTRAN simulations ("dusty decks") presently in production use.<<ETX>> | false | false | [
"G. David Kerlick",
"E. Kirby"
] | [] | [] | [] |
Vis | 1,993 | Unsteady phenomena, hypersonic flows and co-operative flow visualization in aerospace research | 10.1109/VISUAL.1993.398894 | Some techniques developed recently at DLR's Institute of Theoretical Fluid Mechanics in order to cope with the demands arising from today's work in aerodynamics are illustrated. Such new demands arise from new aerodynamical problems like the hypersonic flow field around re-entry vehicles, the study of unsteady phenomena which comes more and more within reach due to the increased availability of computing power and the tendency towards enhanced international cooperation especially within Europe which calls for the use of co-operative systems on wide area networks.<<ETX>> | false | false | [
"Hans-Georg Pagendarm"
] | [] | [] | [] |
Vis | 1,993 | Virtual input devices for 3D systems | 10.1109/VISUAL.1993.398862 | The device unified interface is a generalized and easily expandable protocol for the communication between applications and input devices. The key idea is to unify various device data into the parameters of a so-called "virtual input device." The device information-base, which includes device dependent information, is also incorporated into the virtual input device. Using the device unified interface, system builders are able to design their applications independent of the input devices as well as utilize the capabilities of several devices in the same application.<<ETX>> | false | false | [
"Taosong He",
"Arie E. Kaufman"
] | [] | [] | [] |
Vis | 1,993 | Visual feedback in querying large databases | 10.1109/VISUAL.1993.398864 | In this paper, we describe a database query system that provides visual relevance feedback in querying large databases. The goal of our system is to support the query specification process by using each pixel of the display to represent one data item of the database. By arranging and coloring the pixels according to their relevance for the query, the user gets a visual impression of the resulting data set. Using sliders for each condition of the query, the user may change the query dynamically and receives immediate feedback by the visual representation of the resulting data set. By using multiple windows for different parts of a complex query, the user gets visual feedback for each part of the query and, therefore, will easier understand the overall result. The system may be used to query any database that contains tens of thousands to millions of data items, but it is especially helpful to explore large data sets with an unknown distribution of values and to find the interesting hot spots in huge amounts of data. The direct feedback allows to visually display the influence of incremental query refinements and, therefore, allows a better, easier and faster query specification.<<ETX>> | false | false | [
"Daniel A. Keim",
"Hans-Peter Kriegel",
"Thomas Seidl 0001"
] | [] | [] | [] |
Vis | 1,993 | Visualization and modeling of geophysical data | 10.1109/VISUAL.1993.398892 | We present the visualization and modeling techniques used in a case study to build feature-based computational models from geophysical data. Visualization was used to inspect the quality of the interpretation of the geophysical data. We describe the geophysical data graphical representation used to support rapid rendering and to enhance the perception differences between the interpretation of the data and the data itself. In addition, we present the modeling techniques used to convert the geophysical data into a feature-based computational model suitable for use by a numerical simulation package.<<ETX>> | false | false | [
"George Celniker",
"Indranil Chakravarty",
"Jan Moorman"
] | [] | [] | [] |
Vis | 1,993 | Visualization of acoustic lens data | 10.1109/VISUAL.1993.398884 | 3-dimensional data visualization from any input source involves the study and understanding of several steps. These steps include data acquisition, signal processing, image processing and image generation. Using a forward-looking high frequency sonar system (which focuses sound much like the eye focuses light), standard and non-standard data processing algorithms, and industry "standard" visualization algorithms, this project produced accurate 3-dimensional representations of several underwater objects.<<ETX>> | false | false | [
"Anthony J. Bladek"
] | [] | [] | [] |
Vis | 1,993 | Visualization of oil reservoirs over a large range of scales as a catalyst for multi-disciplinary integration | 10.1109/VISUAL.1993.398893 | We discuss a system which provides a single, unified model of oil and gas reservoirs that is used across a range of disciplines from geologists to reservoir engineers. It has to store, manipulate and display reservoir phenomena which are observed over several orders of magnitude from 1 mm to 10 km. We propose that the current capabilities of visualization, over this range of scales, can remove perception barriers that have existed between disciplines and provide clear insights into the problems of modeling reservoirs from geological and engineering perspectives.<<ETX>> | false | false | [
"S. Tyson",
"B. Williams"
] | [] | [] | [] |
Vis | 1,993 | Visualization of stratospheric ozone depletion and the polar vortex | 10.1109/VISUAL.1993.398899 | Direct analysis of spacecraft observations of stratospheric ozone yields information about the morphology of annual austral depletion. Visual correlation of ozone with other atmospheric data illustrates the diurnal dynamics of the polar vortex and contributions from the upper troposphere, including the formation and breakup of the depletion region each spring. These data require care in their presentation to minimize the introduction of visualization artifacts that are erroneously interpreted as data features. Non-geographically registered data of differing mesh structures can be visually correlated via cartographic warping of underlying geometries without interpolation. Since this approach is independent of realization technique, it provides a framework for experimenting with different visualization strategies. This methodology preserves the fidelity of the original data sets in a coordinate system suitable for three-dimensional, dynamic examination of upper atmospheric phenomena.<<ETX>> | false | false | [
"Lloyd Treinish"
] | [] | [] | [] |
Vis | 1,993 | Visualization of time-dependent flow fields | 10.1109/VISUAL.1993.398848 | Presently, there are very few visualization systems available for time-dependent flow fields. Although existing visualization systems for instantaneous flow fields may be used to view time-dependent flow fields at discrete points in time, the time variable is usually not considered in the visualization technique. We present a simple and effective approach for visualizing time-dependent flow fields using streaklines. A system was developed to demonstrate this approach. The system can process many time frames of flow fields without requiring that all the data be in memory simultaneously, and it also handles flow fields with moving grids. We have used the system to visualize streaklines from several large 3-D time-dependent flow fields with moving grids. The system was able to provide useful insights to the physical phenomena in the flow fields.<<ETX>> | false | false | [
"David A. Lane"
] | [] | [] | [] |
Vis | 1,993 | Visualization of turbulent flow with particles | 10.1109/VISUAL.1993.398850 | In this work a new method for visualization of three-dimensional turbulent flow using particle motion animation is presented. The method is based on Reynolds decomposition of a turbulent flow field into a convective and a turbulent motion. At each step of particle path generation a stochastic perturbation is added, resulting in random-walk motions of particles. A physical relation is established between the perturbations and the eddy-diffusivity, which is calculated in a turbulent flow simulation. The flow data used is a mean velocity field, and an eddy-diffusivity field. The erratic particle motions are more than just a visual effect, but represent a real physical phenomenon. An implementation of the method is described, and an example of a turbulent channel flow is given, which clearly shows the random particle motions in their context of general fluid motion patterns.<<ETX>> | false | false | [
"Andrea J. S. Hin",
"Frits H. Post"
] | [] | [] | [] |
Vis | 1,993 | Visualizing results of transient flow simulations | 10.1109/VISUAL.1993.398896 | This work briefly describes our approach to visualize results of transient flow simulations in the application areas of groundwater flow and pollutant transport as well as compressible fluid flow in engine parts. The simulations use finite element data structures and can have geometries which change over time. We designed a client-server model to handle the huge amount of data that can be obtained either directly from the simulation process or from files on disk. As standard visualization packages are not able to cope with transient unstructured data, we implemented streamlines, stream surfaces and particle systems as our main visualization methods. Our experiences and results with these techniques are discussed in this paper.<<ETX>> | false | false | [
"Harald F. Mayer",
"Behnam Tabatabai"
] | [] | [] | [] |
Vis | 1,993 | Volume sampled voxelization of geometric primitives | 10.1109/VISUAL.1993.398854 | We present a 3-D antialiasing algorithm for voxel-based geometric models. The technique band-limits the continuous object before sampling it at the desired 3-D raster resolution. By precomputing tables of filter values for different types and sizes of geometric objects, the algorithm is very efficient and has a complexity that is linear with the number of voxels generated. The algorithm not only creates voxel models which are free from object space aliasing, but it also incorporates the image space antialiasing information as part of the view independent voxel model. The resulting alias-free voxel models have been used to model synthetic scenes, for discrete ray tracing applications. The discrete ray-traced image is superior in quality to the image generated with a conventional surface-based ray tracer, since silhouettes of objects, shadows, and reflections appear smooth (jaggy-less). In addition, the alias-free models are also suitable for intermixing with sampled datasets, since they can be treated uniformly as one common data representation.<<ETX>> | false | false | [
"Sidney W. Wang",
"Arie E. Kaufman"
] | [] | [] | [] |
CHI | 1,993 | A space based model for user interaction in shared synthetic environments | 10.1145/169059.169068 | In a distributed shared synthetic environment with provisions for high quality 3D visualization and interaction, it is possible to implement a powerful variant of a rooms/space metaphor based on the concept of presence or proximity between participants in 3D space. This kind of model can be used as an interface between the user and the computer, for overview and control of applications, file systems, networks and other computer resources, as well as for communication and collaboration with other users in the networked environment. We model proximity with a geometric volume of the immediate surroundings, the aura, of the participant's representation in the synthetic environment. This proximity, or aura, is used to establish presence at meetings, to establish communication channels and to provide interaction. | false | false | [
"Lennart E. Fahlén",
"Charles Grant Brown",
"Olov Ståhl",
"Christer Carlsson"
] | [] | [] | [] |
CHI | 1,993 | A synergistic approach to specifying simple number independent layouts by example | 10.1145/169059.169221 | A grid-based technique to specify simple number independent layouts by example is described. This technique was originally developed to support layout specification for a parallel program visualization system but can be applied to aid other simple graphical layout tasks as well. The technique works by allowing the user to construct an example layout using a grid-based interaction technique. This example can then be generalized into a layout algorithm which can be applied to create layouts of any size. However, rather than simply choosing the “best” generalization, the system described here takes a synergistic approach. New examples from a set of alternative generalizations are presented to the user so that they can guide and control the generalization process. This provides more understanding and control of the generalization to be constructed from only one small example. | false | false | [
"Scott E. Hudson",
"Chen-Ning Hsi"
] | [] | [] | [] |
CHI | 1,993 | Automatic structure visualization for video editing | 10.1145/169059.169118 | We developed intelligent functions for the automatic description of video structure, and visualization methods for temporal-spatial video structures obtained by these functions as well as for the functions. The functions offer descriptions of cut separations, motion of the camera and filmed objects, tracts and contour lines of objects, existence of objects, and periods of existence. Furthermore, identical objects are automatically linked. Thus the visualization methods supported by object-links allow users to freely browse and directly manipulate the structure including descriptions and raw video data. | false | false | [
"Hirotada Ueda",
"Takafumi Miyatake",
"Shigeo Sumino",
"Akio Nagasaka"
] | [] | [] | [] |
CHI | 1,993 | Beyond interface builders: model-based interface tools | 10.1145/169059.169305 | Interface builders only support the construction of the menus and dialogue boxes of an application. They do not support the construction of interfaces of many application classes (visualization, simulation, command and control, domain-specific editors) because of the dynamic and complex information that these applications process. HUMANOID is a model-based interface design and construction tool where interfaces are specifkd by building a declarative description (model) of their presentation and behavior. HUMANOID’S modeling language provides simple abstraction, iteration and conditional constructs to model the interface features of these application classes. HUMANOID provides an easy-touse designer’s interface that lets designers build complex interfaces without programming. | false | false | [
"Pedro A. Szekely",
"Ping Luo",
"Robert Neches"
] | [] | [] | [] |
CHI | 1,993 | Fish tank virtual reality | 10.1145/169059.169066 | The defining characteristics of what we call “Fish Tank Virtual Reality” are a stereo image of a three dimensional (3D) scene viewed on a monitor using a perspective projection coupled to the head position of the observer. We discuss some of the relative merits of this mode of viewing as compared to head mounted stereo displays. In addition, we report the experimental investigation of the following variables: 1) whether or not the perspective view is coupled to the actual viewpoint of the observer, 2) whether stereopsis is employed. Experiment 1 involved the subjective comparison of pairs of viewing conditions and the results suggest that head coupling may be more important than stereo in yielding a strong impression of three dimensionality. Experiment 2 involved subjects tracing a path from a leaf of a 3D tree to the correct root (there were two trees intermeshed). The error rates ranged from 22% in the pictorial display, to 1.3% in the head coupled stereo display. The error rates for stereo alone and head coupling alone were 14.7% and 3.2% respectively. We conclude that head coupling is probably more important than stereo in 3D visualization and that head coupling and stereo combined provide an important enhancement to monitor based computer graphics. | false | false | [
"Colin Ware",
"Kevin Arthur",
"Kellogg S. Booth"
] | [] | [] | [] |
CHI | 1,993 | High interaction data visualization using Seesoft to visualize program change history (abstract) | 10.1145/169059.169480 | A problem in developing large software systems is understanding the source code. This problem is difficult because of the volume of code. The listing for a moderately sized system with 100,000 lines, printed 50 lines per page, would run 2,000 pa~s. This video shows a new software tool, Seesoft , that applies scientific visualization techniques to visualizing code. The visualization approach is to represent files in a directoty in columns and the source code lines as rows of colored pixels. The indentation and length of each row of pixe18 corresponds to the actual code. The color of each row of pixels is determined by a statistic such as the age, programmer, or type of line, that we obtain from the change management system. The visual impression is that of a miniature picture of the source code with the indentation showing the usual C controls structure and the color showing the spatial distribution of the statistic. A user may adjust the display using direct manipulation techniques to discover interesting patterns in the code. Software engineering concepts such as complexity and bug fix on fix density can be visualized. The main interest of this work to the human factors community is the use of graphical user interface for selecting and combining statistics from a database, the effective use of hundreds of colors to display a mass of data, and the reduction of the point-and-click direct manipulation metaphor to just pointing, e.g. something of interest will occur where ever the mouse points to on the display. | false | false | [
"Joseph L. Steffen",
"Stephen G. Eick"
] | [] | [] | [] |
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