By Topic

Visualization, 1994., Visualization '94, Proceedings., IEEE Conference on

Date 21-21 Oct. 1994

Filter Results

Displaying Results 1 - 25 of 60
  • Proceedings Visualization '94

    Publication Year: 1994
    Save to Project icon | Request Permissions | PDF file iconPDF (20 KB)  
    Freely Available from IEEE
  • Volume rendering methods for computational fluid dynamics visualization

    Publication Year: 1994 , Page(s): 232 - 239, CP26
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (648 KB)  

    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 View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • New techniques in the design of healthcare facilities

    Publication Year: 1994 , Page(s): 374 - 377, CP43
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (284 KB)  

    The recent advent of computer graphics techniques has helped to bridge the gap between architectural concepts and actual buildings. Closing this gap is especially critical in healthcare facilities. We present new techniques to support the design decision process and apply them to the design of a neonatal intensive care unit. Two issues are addressed: ergonometric accessibility and visual supervision of spaces. These two issues can be investigated utilizing new technologies that demonstrate that computers are more then a medium of communication in the field of architecture; the computer can make a significant contribution as a proactive design tool View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An annotation system for 3D fluid flow visualization

    Publication Year: 1994 , Page(s): 273 - 279, CP31
    Cited by:  Papers (2)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (484 KB)  

    Annotation is a key activity of data analysis. However, current data analysis systems focus almost exclusively on visualization. We propose a system which integrates annotations into a visualization system. Annotations are embedded in 3D data space, using the Post-it metaphor. This embedding allows contextual-based information storage and retrieval, and facilitates information sharing in collaborative environments. We provide a traditional database filter and a Magic Lens filter to create specialized views of the data. The system is customized for fluid flow applications, with features which allow users to store parameters of visualization tools and sketch 3D volumes View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Visualization of 3D ultrasonic data

    Publication Year: 1994 , Page(s): 369 - 373, CP42
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (484 KB)  

    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 View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Observing a volume rendered fetus within a pregnant patient

    Publication Year: 1994 , Page(s): 364 - 368, CP41
    Cited by:  Papers (13)  |  Patents (21)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (716 KB)  

    Augmented reality systems with see-through headmounted displays have been used primarily for applications that are possible with today's computational capabilities. We explore possibilities for a particular application-in-place, real-time 3D ultrasound visualization-without concern for such limitations. The question is not “How well could we currently visualize the fetus in real time,” but “How well could we see the fetus if we had sufficient compute power?” Our video sequence shows a 3D fetus within a pregnant woman's abdomen-the way this would look to a HMD user. Technical problems in making the sequence are discussed. This experience exposed limitations of current augmented reality systems; it may help define the capabilities of future systems needed for applications as demanding as real-time medical visualization View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Feature detection from vector quantities in a numerically simulated hypersonic flow field in combination with experimental flow visualization

    Publication Year: 1994 , Page(s): 117 - 123, CP12
    Cited by:  Papers (10)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (704 KB)  

    In computational fluid dynamics visualization is a frequently used tool for data evaluation, understanding of flow characteristics, and qualitative comparison to flow visualizations originating from experiments. Building on an existing visualization software system, that allows for a careful selection of state-of-the-art visualization techniques and some extensions, it became possible to present various features of the data in a single image. The visualizations show vortex position and rotation as well as skin-friction lines, experimental oil-flow traces, and shock-wave positions. By adding experimental flow visualization a comparison between numerical simulation and wind-tunnel flow becomes possible up to a high level of detail. Since some of the underlying algorithms are not yet described in detail in the visualization literature, some experiences gained from the implementation are illustrated View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Strata-various: multi-layer visualization of dynamics in software system behavior

    Publication Year: 1994 , Page(s): 172 - 178, CP19
    Cited by:  Papers (10)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (572 KB)  

    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 View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Triangulation and display of rational parametric surfaces

    Publication Year: 1994 , Page(s): 69 - 76, CP6
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (620 KB)  

    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 View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Approximation of isosurface in the Marching Cube: ambiguity problem

    Publication Year: 1994 , Page(s): 288 - 292
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (300 KB)  

    The purpose of the article is the consideration of the problem of ambiguity over the faces arising in the Marching Cube algorithm. The article shows that for unambiguous choice of the sequence of the points of intersection of the isosurface with edges confining the face it is sufficient to sort them along one of the coordinates. It also presents the solution of this problem inside the cube. Graph theory methods are used to approximate the isosurface inside the cell View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Visualizing data: is virtual reality the key?

    Publication Year: 1994 , Page(s): 410 - 413
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (332 KB)  

    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 View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Differential volume rendering: a fast volume visualization technique for flow animation

    Publication Year: 1994 , Page(s): 180 - 187, CP20
    Cited by:  Papers (23)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (640 KB)  

    We present a direct volume rendering algorithm to speed up volume animation for flow visualizations. Data coherency between consecutive simulation time steps is used to avoid casting rays from those pixels retaining color values assigned to the previous image. The algorithm calculates the differential information among a sequence of 3D volumetric simulation data. At each time step the differential information is used to compute the locations of pixels that need updating and a ray-casting method as utilized to produce the updated image. We illustrate the utility and speed of the differential volume rendering algorithm with simulation data from computational bioelectric and fluid dynamics applications. We can achieve considerable disk-space savings and nearly real-time rendering of 3D flows using low-cost, single processor workstations for models which contain hundreds of thousands of data points View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Visualizing flow with quaternion frames

    Publication Year: 1994 , Page(s): 108 - 115, CP11
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (496 KB)  

    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 View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A library for visualizing combinatorial structures

    Publication Year: 1994 , Page(s): 164 - 171, CP18
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (628 KB)  

    Describes ANIM3D, a 3D animation library targeted at visualizing combinatorial structures. In particular, we are interested in algorithm animation. Constructing a new view for an algorithm typically takes dozens of design iterations, and can be very time-consuming. Our library eases the programmer's burden by providing high-level constructs for performing animations, and by offering an interpretive environment that eliminates the need for recompilations. We also illustrate ANIM3D's expressiveness by developing a 3D animation of Dijkstra's shortest-path algorithm in just 70 lines of code View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Piecewise-linear surface approximation from noisy scattered samples

    Publication Year: 1994 , Page(s): 61 - 68
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (620 KB)  

    We consider the problem of approximating a smooth surface f(x, y), based on n scattered samples {(xi, yi, zi )i=1n} where the sample values {zi} are contaminated with noise: zi=f(xi , yi)=εi. We present an algorithm that generates a PLS (piecewise linear surface) f', defined on a triangulation of the sample locations V={(xi, yi) i=1n}, 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 View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • 3D visualization of unsteady 2D airplane wake vortices

    Publication Year: 1994 , Page(s): 124 - 131, CP13
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (780 KB)  

    Air flowing around the wing tips of an airplane forms horizontal tornado-like vortices that can be dangerous to following aircraft. The dynamics of such vortices, including ground and atmospheric effects, can be predicted by numerical simulation, allowing the safety and capacity of airports to be improved. We introduce three-dimensional techniques for visualizing time-dependent, two-dimensional wake vortex computations, and the hazard strength of such vortices near the ground. We describe a vortex core tracing algorithm and a local tiling method to visualize the vortex evolution. The tiling method converts time-dependent, two-dimensional vortex cores into three-dimensional vortex tubes. Finally, a novel approach is used to calculate the induced rolling moment on the following airplane at each grid point within a region near the vortex tubes and thus allows three-dimensional visualization of the hazard strength of the vortices View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Visualization of volcanic ash clouds

    Publication Year: 1994 , Page(s): 386 - 390, CP46
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (368 KB)  

    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 View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Validation, verification and evaluation

    Publication Year: 1994 , Page(s): 414 - 418
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (420 KB)  

    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? View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Visualizing multidimensional (multivariate) data and relations

    Publication Year: 1994 , Page(s): 404 - 409
    Cited by:  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (348 KB)  

    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 View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A distributed, parallel, interactive volume rendering package

    Publication Year: 1994 , Page(s): 21 - 30, CP2
    Cited by:  Papers (7)  |  Patents (21)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (632 KB)  

    This paper presents a parallel ray-casting volume rendering algorithm and its implementation on the massively parallel IBM SP-1 computer using the Chameleon message passing library. Though this algorithm takes advantage of many of the unique features of the SP-1 (e.g. high-speed switch, large memory per node, high-speed disk array, HIPPI display, et al.), the use of Chameleon allows the code to be executed on any collection of workstations. The algorithm is image-ordered and distributes the data and the computational load to individual processors. After the volume data is distributed, all processors then perform local ray tracing of their respective subvolumes concurrently. No interprocess communication takes place during the ray tracing process. After a subimage is generated by each processor, the final image is obtained by composing subimages between all the processors. The program itself is implemented as an interactive process through a GUI residing on a graphics workstation which is coupled to the parallel rendering algorithm via sockets. The paper highlights the Chameleon implementation, the GUI, some optimization improvements, static load balancing, and direct parallel display to a HIPPI framebuffer View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The topology of symmetric, second-order tensor fields

    Publication Year: 1994 , Page(s): 140 - 147, CP15
    Cited by:  Papers (22)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (752 KB)  

    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 View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Virtual reality performance for virtual geometry

    Publication Year: 1994 , Page(s): 156 - 163, CP17
    Cited by:  Papers (5)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (836 KB)  

    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 View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Implicit modeling of swept surfaces and volumes

    Publication Year: 1994 , Page(s): 40 - 45, CP4
    Cited by:  Papers (13)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (484 KB)  

    Swept surfaces and volumes are generated by moving a geometric model through space. Swept surfaces and volumes are important in many computer-aided design applications including geometric modeling, numerical cutter path generation, and spatial path planning. In this paper we describe a numerical algorithm to generate swept surfaces and volumes using implicit modeling techniques. The algorithm is applicable to any geometric representation for which a distance function can be computed. The algorithm also treats degenerate trajectories such as self-intersection and surface singularity. We show applications of this algorithm to maintainability design and robot path planning View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A lattice model for data display

    Publication Year: 1994 , Page(s): 310 - 317
    Cited by:  Papers (9)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (592 KB)  

    In order to develop a foundation for visualization, we develop lattice models for data objects and displays that focus on the fact that data objects are approximations to mathematical objects and real displays are approximations to ideal displays. These lattice models give us a way to quantize the information content of data and displays and to define conditions on the visualization mappings from data to displays. Mappings satisfy these conditions if and only if they are lattice isomorphisms. We show how to apply this result to scientific data and display models, and discuss how it might be applied to recursively defined data types appropriate for complex information processing View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Introducing alpha shapes for the analysis of path integral Monte Carlo results

    Publication Year: 1994 , Page(s): 52 - 59
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (692 KB)  

    We present a new technique for the visualization and analysis of the results from Monte Carlo simulations based on α-complexes and α-shapes. The specific application presented is the analysis of the quantum-mechanical behavior of hydrogen molecules and helium atoms on a surface at very low temperatures. The technique is an improvement over existing techniques in two respects. First, the approach allows one to visualize the points on a random walk at varying levels of detail and interactively select the level of detail that is most appropriate. Second, using α-shapes one can obtain quantitative measures of spatial properties of the system, such as the boundary length and interior area of clusters, that would be difficult to obtain otherwise View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.