IEEE VIS Publication Dataset

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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