IEEE VIS Publication Dataset

A methodology for guiding the choice of visual representations of data is presented. The methodology provides objective and directed display design facilities. Such facilities can guide interactive visualization design, generate standard visualizations automatically, and assess the extent to which chosen representations can convey the required information to data analysis. The methodology is based on objectively distinguishing the types of information conveyed by various visual representations and matching these to the intrinsic characteristics of data and to aims for its interpretation. This approach is directed toward developing a stronger theoretical basis for visualization in scientific computation. The methodology is developed using a natural scene paradigm in which data variables are represented by identifiable properties of realistic scenes

Methods of rendering reflections in curved surfaces are examined. A numerical algorithm to derive spherical reflections is presented. This algorithm has many attractive qualities, such as low computation costs, object space coherence, device and resolution independence, and generation of maximum information about reflections in curved surfaces. The authors demonstrate that rendering reflections is a difficult problem, as it defies analytic solutions. The authors indicate several alternatives for generalizing this method to a broader domain

Progress in scientific visualization could be accelerated if workers could more readily find visualization techniques relevant to a given problem. The authors describe an approach to this problem, based on a classification of visualization techniques, that is independent of particular application domains. A user breaks up a problem into subproblems, describes these subproblems in terms of the objects to be represented and the operations to be supported by a representation, locates applicable visualization techniques in a catalog, and combines these representations into a composite representation for the original problem. The catalog and its underlying classification provide a way for workers in different application disciplines to share methods

The author presents a simple, procedural interface for volume rendering. The interface is built on three types of objects: volumes, which contain the data to be visualized, environments, which set up viewing and lighting, and image objects, which convert results to a user-definable format. A volume is rendered against a particular environment with the results sent to an image object for conversion. By defining volume qualities such as color, opacity, and gradient in terms of user-definable transfer functions, the rendering process is made independent of the data set's underlying representation

The authors describe the real-time acoustic display capabilities developed for the virtual environment workstation (VIEW) project. The acoustic display is capable of generating localized acoustic cues in real time over headphones. An auditor symbology, a related collection of representational auditory objects or icons, can be designed using the auditory cue editor, which links both discrete and continuously varying acoustic parameters with information or events in the display. During a given display scenario, the symbology can be dynamically coordinated in real time with three-dimensional visual objects, speech, and gestural displays. The types of displays feasible with the system range from simple warnings and alarms to the acoustic representation of multidimensional data or events

A forecasting system for the Great Lakes in which the data generated by a three-dimensional numerical model is visualized by a 3-D/stereoscopic display module is discussed. The module consists of a control panel and a display window with the capability of interactively rendering the results. The event scheduling for scenario testing to steer the 3-D numerical model is achieved by a similar panel. These panels set up the simulation and control the data flow between the graphics workstation and supercomputer. Rendering methods, stereo imagery, and animation are incorporated to display the results. Interaction between the user, the workstation, and the supercomputer allows steering of the simulation and tracing of the simulation output. Distributed software for postprocessing and volume rendering are used to enhance the representation

A general method for rendering isosurfaces of multivariate rational and polynomial tensor products is described. The method is robust up to degree 15, handling singularities without introducing spurious rendering artifacts. The approach does not solve the problem of singularities in general, but it removes the problem from the rendering domain to the interpolation/approximation domain. It is based on finding real roots of a polynomial in Bernstein form. This makes it particularly suitable for parallel and pipelined processing. It is envisioned that the tensor products will be used as approximants or interpolants for empirical data or scalar fields. An interpolation scheme is given as an example

MediaView is a computer program that provides a generic infrastructure for authoring and interacting with multimedia documents. Among its applications is the ability to furnish a user with a comprehensive environment for analysis and visualization. With this program the user can produce a document that contains mathematics, datasets and associated visualizations. From the dataset or embedded mathematics animated sequences can be produced in situ. Equations that appear in a document have a backing format that is compatible with the Mathematica language. Thus, by clicking on an equation, its semantics are conveyed to Mathematica, where the user can perform a variety of symbolic and numerical operations. Since the document is all digital, it can be shared on a local network or mailed electronically to a distant site. Animations and any other substructures of the document persist through the mailing process and can be awakened at the destination by the recipient

The animation of two-dimensional objects in a 2-D planar environment is discussed. The use of chain codes as a boundary representation for 2-D objects undergoing animation is shown to be practical for several typical transformations. Various methods for implementing the transformations are described. Quantized methods transform groups of chain code elements into other groups, while incremental methods construct the transformed chain code element by element. The low cost of quantized methods, which rely on table lookup and minimal arithmetic, are weighed against the increased accuracy offered by incremental methods, which maintain error indicators to ensure minimal differences between ideal and generated chain codes. Methods for scaling, rotation, and elastic deformation of objects based solely on chain code elements are discussed

We present a new ray-tracing algorithm for volume rendering which is designed to work efficiently when the data of interest is distributed sparsely through the volume. A simple preprocessing step identifies the voxels representing features of interest. Frequently this set of voxels, arbitrarily distributed in three dimensional space, is a small fraction of the original voxel grid. A mediancut space partitioning scheme, combined with bounding volumes to prune void spaces in the resulting search structure, is used to store the voxels of interest in a kd tree. The tree is then efficiently ray-traced to render the voxel data. The k-d tree is view independent and can be used for animation sequences involving changes in positions of the viewer or positions of lights. We have applied this search structure to render voxel data from MRI, CAT Scan and electron density distributions.

The authors present techniques for automating the illustration of geometric models based on traditional hand illustration methods. A system based on the techniques of traditional illustrators for automatically generating illustrations of complex three-dimensional models is described. The system relies on a richer set of display primitives, which are also outlined. Algorithmic details for emphasizing significant model components are discussed, and some preliminary results are presented

The problem of presenting and gaining deeper understanding of a multidimensional system, a mathematical model Predicting 20-90 s oscillations in breathing, is presented. The authors utilized custom software for interactive analysis of a three-dimensional model, plus Wavefront software to render translucent images of the 3D surfaces. The results show that under conditions of no peripheral chemosensor sensitivity, periodic breathing is predicted to occur with (1) an increase in circulatory transit time between the lungs and brain, (2) the presence of marked steady state hypoventilation, and/or (3) an increase in brain blood flow rate. It is concluded that the peripheral chemosensors (carotid bodies) are not essential for the development of periodic breathing

An exploratory effort to classify visual representations into homogeneous clusters is discussed. The authors collected hierarchical sorting data from twelve subjects. Five principal groups of visual representations emerged from a cluster analysis of sorting data: graphs and tables, maps, diagrams, networks, and icons. Two dimensions appear to distinguish these clusters: the amount of spatial information and cognitive processing effort. The authors discuss visual information processing issues relevant to the research, methodology and data analyses used to develop the classification system, results of the empirical study, and possible directions for future research

The authors describe the architecture of an end-user visualization system that supports interactive analysis of three-dimensional scalar and vector data in a heterogeneous hardware environment. The system supports a variety of visualization methods with applicability in disciplines such as computational fluid dynamics, earth, and space sciences, and finite-element analysis. The authors discuss how design goals and hardware constraints lead to a simple, cohesive paradigm for implementing a powerful, flexible, and portable visualization system. To assure efficient operation across a broad range of hardware platforms, the tools were implemented so that their interactivity is largely independent of data complexity. To gain portability, the system was built on a platform-independent graphics layer and user interface management system. The authors outline general concerns with current visualization methods and show how the approach simplifies the visualization process

The use of qualitative shape synthesis for the display of 3-D binary objects is presented. The proposed approach is applicable to multi-object scenes and to outdoor scenery as well. It makes use of a new method, the diffusion process, that simulates diffusion of particles within the interior of a 3-D discrete object. Starting with initial concentrations of particles at the boundary-voxels, the diffusion procedure simulates the propagation of these particles inwards. Boundary voxels of the object are colored according to the concentration of particles obtained by suspending the diffusion process. This method assists shape characterization by providing a qualitative measure of boundary curvature and was used in achieving display of a variety of voxel-based objects. Examples of the use of this approach on synthetic, terrain, and range data, are provided

The authors describe several dynamic graphics tools for visualizing network data involving statistics associated with the nodes or links in a network. The authors suggest a number of ideas for the static display of network data, while motivating the need for interaction through dynamic graphics. A brief discussion of dynamic graphics in general is presented. The authors specialize this to the case of network data. An example is presented

The ability of researchers in the scientific and engineering community to generate or acquire data far outstrips their ability to analyze it. This problem is even more pronounced when the data is of high dimensionality. Visualization has been identified as a critical technique for exploring data sets, but the visualization tools developed to date have mostly concentrated on the display of low (one to four) dimensional data. Ideally a tool for examining N-dimensional data should allow the presentation of the data in a way that can be intuitively interpreted and allow the display of arbitrary views and subsets of the data. The work presented in this paper describes the creation of such a tool using a technique which we term dimensional stacking.

The authors propose a methodology that will extract a topologically closed geometric model from a two-dimensional image. This is accomplished by starting with a simple model that is already topologically closed and deforming the model, based on a set of constraints, so that the model grows (shrinks) to fit the feature within the image while maintaining its closed and locally simple nature. The initial model is a non-self-intersecting polygon that is either embedded in the feature or surrounds the feature. There is a cost function associated with every vertex that quantifies its deformation, the properties of simple polygons, and the relationship between noise and feature. The constraints embody local properties of simple polygons and the nature of the relationship between noise and the features in the image

The authors discuss FAST (flow analysis software toolkit), an implementation of a software system for fluid mechanics analysis. Visualization of computational aerodynamics requires flexible, extensible, and adaptable software tools for performing analysis tasks. An overview of FAST is given, and its architecture is discussed. Interactive visualization control is addressed. The advantages and disadvantages of FAST are discussed

A hierarchical triangulation built from a digital elevation model in grid form is described. The authors present an algorithm that produces a hierarchy of triangulations in which each level of the hierarchy corresponds to a guaranteed level of accuracy. The number of very thin triangles (slivers) is significantly reduced. Such triangles produced undesirable effects in animation. In addition the number of levels of the triangulated irregular network (TIN) tree is reduced. This speeds up searching within the data structure. Tests on data with digital elevation input have confirmed the theoretical expectations. On eight such sets the average sliveriness with the method was between 1/5 and 1/10 of old triangulations and number of levels was about one third. There was an increase in the number of descendants at each level, but the total number of triangles was also lower