IEEE VIS Publication Dataset

A standard method for visualizing vector fields consists of drawing many small ÔÇ£glyphsÔÇØ to represent the field. This paper extends the technique from regular to curvilinear and unstructured grids. In order to achieve a uniform density of vector glyphs on nonuniformly spaced grids, the paper describes two approaches to resampling the grid data. One of the methods, an element-based resampling, can be used to visualize vector fields at arbitrary surfaces within three-dimensional grids

Advances in computer graphics hardware and algorithms, visualization, and interactive techniques for analysis offer the components for a highly integrated, efficient real-time 3D Geographic Information System. We have developed ÔÇ£Virtual GISÔÇØ, a system with truly immersive capability for navigating and understanding complex and dynamic terrain-based databases. The system provides the means for visualizing terrain models consisting of elevation and imagery data, along with GIS raster layers, protruding features, buildings, vehicles, and other objects. We have implemented window-based and virtual reality versions and in both cases provide a direct manipulation, visual interface for accessing the GIS data. Unique terrain data structures and algorithms allow rendering of large, high resolution datasets at interactive rates

Visualization, animation, and simulation techniques are applied to the problem of rotor design for helicopters. Periodic unsteady experimental velocity data (laser Doppler velocimetry or LDV) in two dimensions and velocity data derived from simulated vortex systems in three dimensions are compared using the same visual tools. Animations show the development of rotor wake systems and induced velocities over time. Modified particle trace integration schemes are used to calculate steady streamlines and unsteady particle paths for both kinds of data. In an extension of this work, a virtual environment (VE) system was used to view the wake vortex system and an interactive probe was used to explore the induced velocity field. Future work will enable interactive visual debugging and simulation steering

Biological sequence similarity analysis presents visualization challenges, primarily because of the massive amounts of discrete, multi dimensional data. Genomic data generated by molecular biologists is analyzed by algorithms that search for similarity to known sequences in large genomic databases. The output from these algorithms can be several thousand pages of text, and is difficult to analyze because of its length and complexity. We developed and implemented a novel graphical representation for sequence similarity search results, which visually reveals features that are difficult to find in textual reports. The method opens new possibilities in the interpretation of this discrete, multidimensional data by enabling interactive investigation of the graphical representation

Three topics of aerodynamic research at DLR are chosen to illustrate the need for visualization. These include aircraft configuration design variations, adaptation devices and unsteady flow simulation in the transonic, the supersonic and the hypersonic speed regime call for the combined use of a geometry generator, a powerful graphic system and video technology. Projects currently under investigation are illustrated and generic case studies are presented

A new method of tracking free ranging marine mammals has been developed which employs a Global Positioning System (GPS) receiver to accurately fix an animal's position when it surfaces and a tri axial magnetometer and velocity time depth recorder to track the animals underwater movements between surfacings in 3 dimensions. Concurrent with the development of the electronics of this movement and position tracking (MAP) tracking system has been the development of ways to analyze data from the MAP system. Spray rendering has been used to visualize the data and to combine it with environmental data allowing biologists view the animals activity in an environmental context. Considerable effort has been has been made to incorporate estimations of uncertainty and ways of minimizing it into our visualizations of the data

Because of the nature of the die casting process, the part geometry severely restricts the die geometry and hence affects the quality of the part. However, as is often the case in other manufacturing processes, diecastings are currently designed purely based on their function. The manufacturability of the diecastings is not considered until the design has been nearly completed and detailed. This is due to the design support limitations of current CAE tools. We present a new volume-based approach to support diecastability evaluation, especially in preliminary design. Our approach can be applied to arbitrarily shaped parts without pre-defined feature libraries. The focus is on the identification of geometric characteristics, e.g. heavy mass regions, that could be responsible for thermal-related part defects. A distance transform with city-block metric is used to extract this geometric property. Volume visualization techniques are also adopted to allow users to visualize the results in a clear and precise way

Presents a simple, robust and practical method for object simplification for applications where gradual elimination of high-frequency details is desired. This is accomplished by sampling and low-pass filtering the object into multi-resolution volume buffers and applying the marching cubes algorithm to generate a multi-resolution triangle-mesh hierarchy. Our method simplifies the genus of objects and can also help existing object simplification algorithms achieve better results. At each level of detail, a multi-layered mesh can be used for an optional and efficient antialiased rendering

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

In this paper we present a method, and a software based on this method, making highly inter-active visualization possible for computational results on nonlinear BVPs associated with ODEs. The program PCR relies partly on computer graphics tools and partly on real-time computations, the combination of which not only helps the understanding of complex problems, it also permits the reduction of stored data by orders of magnitude. The method has been implemented on PCs (running on DOS) and on the Application Visualization System (AVS) for UNIX machines, this paper provides a brief introduction to the latter version besides describing the mathematical background of the method

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

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

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

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

To render images from a three-dimensional array of sample values, it is necessary to interpolate between the samples. This paper is concerned with interpolation methods that are equivalent to convolving the samples with a reconstruction filter; this covers all commonly used schemes, including trilinear and cubic interpolation. We first outline the formal basis of interpolation in three-dimensional signal processing theory. We then propose numerical metrics that can be used to measure filter characteristics that are relevant to the appearance of images generated using that filter. We apply those metrics to several previously used filters and relate the results to isosurface images of the interpolations. We show that the choice of interpolation scheme can have a dramatic effect on image quality, and we discuss the cost/benefit tradeoff inherent in choosing a filter

This paper presents an object-oriented system design supporting the composition of scientific data visualization techniques based on the definition of hierarchies of typed data objects and tools. Traditional visualization systems focus on creating graphical objects which often cannot be re-used for further processing. Our approach provides objects of different topological dimension to offer a natural way of describing the results of visualization mappings. Serial composition of data extraction tools is allowed, while each intermediate visualization object shares a common description and behavior. Visualization objects can be re-used, facilitating the data exploration process by expanding the available analysis and correlation functions provided. This design offers an open-ended architecture for the development of new visualization techniques. It promotes data and software re-use, eliminates the need for writing special purpose software and reduces processing requirements during interactive visualization sessions

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

Visualization will be vital to the success of the NASA EOS Mission to Planet Earth (MTPE), which will gather, generate, and distribute an unprecedented volume of data for the purpose of global change research and environmental policy decisions. The paper focuses on the challenges and opportunities for visualization with regard to the Mission to Planet Earth. Directions presently being taken within NASA to fund and assist development of new tools are also discussed

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

Since the introduction of standard techniques for isosurface extraction from volumetric datasets, one of the hardest problems has been to reduce the number of triangles (or polygons) generated. The paper presents an algorithm that considerably reduces the number of polygons generated by a Marching Cubes-like scheme (W. Lorensen and H. Cline, 1987) without excessively increasing the overall computational complexity. The algorithm assumes discretization of the dataset space and replaces cell edge interpolation by midpoint selection. Under these assumptions, the extracted surfaces are composed of polygons lying within a finite number of incidences, thus allowing simple merging of the output facets into large coplanar polygons. An experimental evaluation of the proposed approach on datasets related to biomedical imaging and chemical modelling is reported