IEEE VIS Publication Dataset

The increasing distinguishing capability of tomographic and other 3D scanners as well as the new voxelization algorithms place new demands on visualization techniques aimed at interactivity and rendition quality. Among others, triangulation on a subvoxel level based on the marching cube algorithm has gained popularity in recent years. However without graphics hardware support, rendering many small triangles could be awkward. We present a surface rendering approach based on ray tracing of segmented volumetric data. We show that if a proper interpolation scheme and voxel traversal algorithm are used, high quality images can be obtained within an acceptable time and without hardware support

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

This paper describes a system, GASP, that facilitates the visualization of geometric algorithms. The user need not have any knowledge of computer graphics in order to quickly generate a visualization. The system is also intended to facilitate the task of implementing and debugging geometric algorithms. The viewer is provided with a comfortable user interface enhancing the exploration of an algorithm's functionality. We describe the underlying concepts of the system as well as a variety of examples which illustrate its use

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

The World-Wide-Web (WWW) has created a new paradigm for online information retrieval by providing immediate and ubiquitous access to digital information of any type from data repositories located throughout the world. The web's development enables not only effective access for the generic user but also more efficient and timely information exchange among scientists and researchers. We have extended the capabilities of the web to include access to three-dimensional volume data sets with integrated control of a distributed client-server volume visualization system. This paper provides a brief background on the World-Wide-Web, an overview of the extensions necessary to support these new data types and a description of an implementation of this approach in a WWW-compliant distributed visualization system

In the process of archaeological excavation, a vast amount of data, much of it three-dimensional in nature, is recorded. In recent years, computer graphics techniques have been applied to the task of visualizing such data. In particular, data visualization has been used to accomplish the virtual reconstruction of site architecture and to enable the display of spatial data distributions using three-dimensional models of site terrain. In the case we present here, these two approaches are integrated in the modeling of a prehistoric pithouse. In order to better visualize artifact distributions in the context of site architecture, surface data is displayed as a layer in a virtual reconstruction viewable at interactive rates. This integration of data display with the architectural model has proven valuable in identifying correlations between distributions of different artifact categories and their spatial proximity to significant architectural features

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

A high-performance algorithm for generating isosurfaces is presented. In this algorithm, extrema points in a scalar field are first extracted. A graph is then generated in which the extrema points are taken as nodes. Each arc of the graph has a list of IDs of the cells that are intersected by the arc. A boundary cell list ordered according to cells' values is also generated. The graph and the list generated in this pre-process are used as a guide in searching for seed cells. Isosurfaces are generated from seed cells that are found in arcs of the graph. In this process, isosurfaces appear to propagate themselves. The algorithm visits only cells that are intersected by an isosurface and cells whose IDs an included in cell lists. It is especially efficient when many isosurfaces are interactively generated in a huge volume. Some benchmark tests described show the efficiency of the algorithm

We present an environment in which users can interactively create different visualization methods. This modular and extensible environment encapsulates most of the existing visualization algorithms. Users can easily construct new visualization methods by combining simple, fine grain building blocks. These components operate on a local subset of the data and generally either look for target features or produce visual objects. Intermediate compositions may also be used to build more complex visualizations. This environment provides a foundation for building and exploring novel visualization methods

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

Surface-based rendering techniques, particularly those that extract a polygonal approximation of an isosurface, are widely used in volume visualization. As dataset size increases though, the computational demands of these methods can overwhelm typically available computing resources. Recent work on accelerating such techniques has focused on preprocessing the volume data or postprocessing the extracted polygonization. The algorithm presented, concentrates instead on streamlining the surface extraction process itself so as to accelerate the rendering of large volumes. The technique shortens the conventional isosurface visualization pipeline by eliminating the intermediate polygonization. We compute the contribution of the isosurface within a volume cell to the resulting image directly from a simplified numerical description of the cell/surface intersection. The approach also reduces the work in the remaining stages of the visualization process. By quantizing the volume data, we exploit precomputed and cached data at key processing steps to improve rendering efficiency. The resulting implementation provides comparatively fast renderings with reasonable image quality

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

Describes a technique for achieving fast volume ray-casting on parallel machines, using a load-balancing scheme and an efficient pipelined approach to compositing. We propose a new model for measuring the amount of work one needs to perform in order to render a given volume, and we use this model to obtain a better load-balancing scheme for distributed memory machines. We also discuss in detail the design trade-offs of our technique. In order to validate our model, we have implemented it on the Intel iPSC/860 and the Intel Paragon, and conducted a detailed performance analysis

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)=ei. 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

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

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

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

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

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

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