IEEE VIS Publication Dataset

FIELDVIEW, a visual analysis tool designed to facilitate the interactive investigation of fluid mechanics data sets by providing an easy-to-use interface to the flow field data, is presented. Operating on NASA Plot three-dimensional format data, FIELDVIEW computes scalar and vector flow quantities and displays them using a variety of representations, including animation. An interactive viewing interface allows free motion around the data under study to allow the researcher to locate and study the interesting flow features of three-dimensional fluid dynamic data

The first half of a two-step quaternion Julia set visualization system is described. This step uses a quarternion square root function to adapt the classic inverse iteration algorithm to the quaternions. The augmented version produces a 3-D Julia set defined by a point cloud that can be interactively manipulated on a graphics workstation. Several cues are assigned to the point cloud to increase depth perception. Finally, a short theorem is proven that extends the domain of the inverse iteration method to a rotational family of quadratic quaternion Julia sets

Visualizing the third dimension while designing three-dimensional (3-D) objects is an awkward process in mechanical computer-aided-design (CAD) systems, given the current state of the art. The authors describe a computer system that automatically constructs the shape of a 3-D object from a single 2-D sketch. The method makes it convenient to create and manipulate 3-D objects, and is thus seen as an intelligent user interface for CAD and 3-D graphics applications. The proposed technique is built on well-known results in image analysis. These results are applied in conjunction with some perceptual rules to determine 3-D structure from a rough line drawing. The principles are illustrated by a computer implementation that works in a nontrivial object domain

The authors discuss various visualization techniques that have the goal of identifying unwanted curvature regions interactively on screen. The authors give a critical survey of surface interrogation methods. Several isoline and contouring techniques are presented, and the reflection line method, which simulates the so-called light cage by computer graphics, is presented. The isophote method analyzes surfaces by determining lines of equal light intensity. Silhouettes are special isophotes. A different approach to these problems is the mapping-technique. The mapping methods recognize unwanted curvature regions by detecting singularities of a special mapping of the curve or surface investigated. Curvature plots are a practical means of analyzing free-form surfaces. All these methods are effective, but generally need a lot of computational effort. The free-form surface visualization by ray tracing is discussed

The idea of independently moving, interacting graphical objects is introduced as a method for the visualization of continuous fields. Bird-oid objects or boids are discussed. These boids derive from: (1) icons which are geometric objects whose shape and appearance are related to the field variables, (2) three-dimensional cursors by which a user interactively picks a point in space, (3) particle traces, which are numerically integrated trajectories in space, (4) moving frames of vectors along space curves, and (5) actors, which are programming objects that can create and destroy instances of themselves, act according to internal logic, and communicate with each other and with a user. A software prototype in the C++ language has been developed which demonstrates some of the capabilities of these objects for the visualization of scalar, vector, and tensor fields defined over finite elements or finite volumes

A methodology for visualizing analytic and synthetic geometry in RN is presented. It is based on a system of parallel coordinates which induces a nonprojective mapping between N-dimensional and two-dimensional sets. Hypersurfaces are represented by their planar images which have some geometrical properties analogous to the properties of the hypersurface that they represent. A point - line duality when N=2 generalizes to lines and hyperplanes enabling the representation of polyhedra in R N. The representation of a class of convex and non-convex hypersurfaces is discussed, together with an algorithm for constructing and displaying any interior point. The display shows some local properties of the hypersurface and provides information on the point's proximity to the boundary. Applications to Air Traffic Control, Robotics, Computer Vision, Computational Geometry, Statistics, Instrumentation and other areas are discussed.

The authors describe an innovative personal visualization system and its application to several research and engineering problems. The system bridges both hardware and software components to permit a user to graphically describe a visualization problem to the computer; thereby reducing program development time to a few hours. Low-cost visualization is achieved using PC-based software that can either be executed on a PC or drive graphic workstations for high-resolution displays. In either case, supercomputer computation rates are available for the visualization process. On PCs this is done with one or more PiP plug in cards, each of which is capable of 100 million floating point operations per second. On workstations this is done with the QUEN array processor. Applications mentioned include: ocean wave imaging; characterizing superconductors; and solar sail visualization

An algorithm for rendering scalar field data that reduces rendering times by as much as two orders of magnitude over traditional full resolution images is presented. Less than full-resolution sampling of the scalar field is performed using a fast ray tracing method. The sampling grid points are output as a set of screen-based Gouraud shaded polygons which are rendered in hardware by a graphics workstation. A gradient-based variable resolution algorithm that further improves rendering speed is presented. Several examples are presented

Visual data analysis (VDA) is a visualization approach that combines vector and raster graphics to provide insights into various aspects of multidimensional datasets. VDA methods have found application in aerospace engineering research, VDA is being used to develop nondestructive evaluation testing techniques for graphite epoxy composites by providing insights into stress waves propagating through them. Visual data analysis was used to analyze stress wave propagation, determine the origin of an unexplained wave distortion, and create a theoretical model to eliminate the distortion utilizing mathematical modeling

The sphere quadtree (SQT), which is based on the recursive subdivision of spherical triangles obtained by projecting the faces of an icosahedron onto a sphere, is discussed. Most databases for spherically distributed data are not structured in a manner consistent with their geometry. As a result, such databases possess undesirable artifacts, including the introduction of tears in the data when they are mapped onto a flat file system. Furthermore, it is difficult to make queries about the topological relationship among the data components without performing real arithmetic. The SQT eliminates some of these problems. The SQT allows the representation of data at multiple levels and arbitrary resolution. Efficient search strategies can be implemented for the selection of data to be rendered or analyzed by a specific technique. Geometric and topological consistency with the data are maintained

A package that can bridge the connection between scattered data sets and the highly structured sets required by graphics algorithms is described. Although export of evaluation data is a necessary capability, it is very important that this package has a fully featured three-dimensional graphics subsystem to interactively guide the researcher toward the final visualization results. At that point the option exists of using more sophisticated and more powerful graphics tools to achieve the desired presentation. The application presented has been designed to effectively meet these needs and to promote the awareness of the value of interpolation tools in visualization. Full details of this design are presented

The author presents a simple and flexible method of sharp coding for higher dimensional data sets that allows the database operator or the scientist quick access to promising patterns within and among records or samples. The example used is a 13-parameter set of solar wind, magnetosphere, and ground observation data collected hourly for 21 days in 1976. The software system is a prototype developed to demonstrate the glyph approach to depicting higher-dimensional data sets. The experiment was to depict all parameters simultaneously, to see if any global or local patterns emerged. This experiment proves that much more complex data can be presented for visual pattern extraction than standard methods allow

Alternative models that use B-spline curves and surfaces for generating color sequences for univariate, bivariate, and trivariate mapping are introduced. The main aim is to break away from simple geometric representation in order to provide more flexibility and control over color selection. This facilitates the task of constructing a customized color scheme for a particular map. The author gives a brief description of existing color schemes and their characteristics, and provides some background for B-spline curves and surfaces

Algorithms for rendering complex and shaded animation sequences are described. The target display device for these image rendering algorithms is a multichannel display based on the superposing technique realized in hardware. An animation sequence is displayed by superposing a dynamic foreground on a static background. The static background can be a very complex scene, and the dynamic foreground can be an image with a simple to medium complexity. These two algorithms were developed based on raytracing

The use of critical point analysis to generate representations of the vector field topology of numerical flow data sets is discussed. Critical points are located and characterized in a two-dimensional domain, which may be either a two-dimensional flow field or the tangential velocity field near a three-dimensional body. Tangent curves are then integrated out along the principal directions of certain classes of critical points. The points and curves are linked to form a skeleton representing the two-dimensional vector field topology. When generated from the tangential velocity field near a body in a three-dimensional flow, the skeleton includes the critical points and curves which provide a basis for analyzing the three-dimensional structure of the flow separation

Some ideas and techniques for visualizing volumetric data are introduced. The methods presented are different from both the volume rendering techniques and surface contour methods. Volumetric data is data with a domain of three independent variables. The independent variables do not have to indicate a position in space and can be abstract in the sense that they can represent any quantity. The authors cover only the case where the dependent data is a single scalar. The authors describe a collection of techniques and ideas for graphing cuberille grid data. All of these techniques are quite simple and rather easy to implement. During the development of these techniques, the authors were particularly concerned with allowing the user to interact with the system in order to interrogate and analyze the relationships indicated by the volumetric data

Computer graphics has long been concerned with representing and displaying surfaces in three-dimensional space. The author addresses the questions of representation and display in a higher dimensional setting, specifically, that of 3-manifolds immersed in four-dimensional space. The author describes techniques for visualizing the cross-section surfaces of a 3-manifold formed by a cutting hyperplane. The manifold is first triangulated, so that the cross-section may be computed on a per tetrahedron basis. The triangulated manifold is stored in a data structure which efficiently supports calculation of curvature. These techniques have been implemented on Personal IRIS

The authors describe some mathematical approaches and computer graphics techniques for illustrating concepts related to Fermat's last theorem. They present a selection of visualization methods, and describe observations made in the process of creating a three-minute computer animated videotape dealing with some elementary aspects of Fermat's last theorem, a problem in number theory. The approach to the representation of the different concepts presented in the video was influenced by many factors: the available hardware, real and perceived constraints of the available software, constraints imposed by the video medium, and a number of peculiarities and features of the mathematical domain itself. The authors describe the experiences with the software systems that played a part in these efforts, some specific successful visualization techniques, and some unexpected mathematical insights

The author describes a visualization model for three-dimensional scalar data fields based on linear transport theory. The concept of virtual particles for the extraction of information from data fields in introduced. The role of different types of interaction of the data field with those particles such as absorption, scattering, source and color shift are discussed and demonstrated. Special attention is given to possible tools for the enhancement of interesting data features. Random texturing can provide visual insights as to the magnitude and distribution of deviations of related data fields, e.g., originating from analytic models, and measurements, or in the noise content of a given data field. Hidden symmetries of a data set can often be identified visually by allowing it to interact with a preselected beam of physical particles with the attendant appearance of characteristic structural effects such as channeling