DevLan/vispubs huggingface dataset:
Archaeological Data Visualization in VR: Analysis of Lamp Finds at the Great Temple of Petra, a Case Study
Authors: Daniel Acevedo Feliz, Eileen Vote, David H. Laidlaw, Martha Sharp Joukowsky
Published at Vis, 2001

Presents the results of an evaluation of the ARCHAVE (ARCHAeological Virtual Environment) system, an immersive virtual reality (VR) environment for archaeological research. ARCHAVE is implemented in a Cave. The evaluation studied researchers analyzing lamp and coin finds throughout the excavation trenches at the Petra Great Temple site in Jordan. Experienced archaeologists used our system to study excavation data, confirming existing hypotheses and postulating new theories they had not been able to discover without the system. ARCHAVE provided access to the excavation database, and researchers were able to examine the data in the context of a life-size representation of the present-day architectural ruins of the temple. They also had access to a miniature model for site-wide analysis. Because users quickly became comfortable with the interface, they concentrated their efforts on examining the data being retrieved and displayed. The immersive VR visualization of the recovered information gave them the opportunity to explore it in a new and dynamic way and, in several cases, enabled them to make discoveries that opened new lines of investigation about the excavation.
Attribute preserving dataset simplification
Authors: Jason D. Walter, Christopher G. Healey
Published at Vis, 2001

The paper describes a novel application of feature preserving mesh simplification to the problem of managing large, multidimensional datasets during scientific visualization. To allow this, we view a scientific dataset as a triangulated mesh of data elements, where the attributes embedded in each element form a set of properties arrayed across the surface of the mesh. Existing simplification techniques were not designed to address the high dimensionality that exists in these types of datasets. In addition, vertex operations that relocate, insert, or remove data elements may need to be modified or restricted. Principal component analysis provides an algorithm-independent method for compressing a dataset's dimensionality during simplification. Vertex locking forces certain data elements to maintain their spatial locations; this technique is also used to guarantee a minimum density in the simplified dataset. The result is a visualization that significantly reduces the number of data elements to display, while at the same time ensuring that high-variance regions of potential interest remain intact. We apply our techniques to a number of well-known feature preserving algorithms, and demonstrate their applicability in a real-world context by simplifying a multidimensional weather dataset. Our results show a significant improvement in execution time with only a small reduction in accuracy; even when the dataset was simplified to 10% of its original size, average per attribute error was less than 1%.
Case study on real-time visualization of virtual Tubingen on commodity PC hardware
Authors: Michael Meißner, Jasmina Orman, Stephan J. Braun
Published at Vis, 2001

For psychophysical studies in spatial cognition a virtual model of the picturesque old town of Tubingen has been constructed. In order to perform psychophysical experiments in highly realistic virtual environments the model is based on high quality texture maps adding up to several hundreds of MBytes. To accomplish the required real-time frame updates, view frustum and occlusion culling without visibility pre-processing, levels of detail, and texture compression are applied in an interleaved manner. Shared memory communication and a standard PC with two commodity graphics cards is used to enable the powerful combination of those techniques because this combination is not yet available on a single graphics card.
Case study: an environment for understanding protein simulations using game graphics
Authors: Donna L. Gresh, Frank Suits, Yuk Yin Sham
Published at Vis, 2001

We describe a visualization system designed for interactive study of proteins in the field of computational biology. Our system incorporates multiple, custom, three-dimensional and two-dimensional linked views of the proteins. We take advantage of modem commodity graphics cards, which are typically designed for games rather than scientific visualization applications, to provide instantaneous linking between views and three-dimensional interactivity on standard personal computers. Furthermore, we anticipate the usefulness of game techniques such as bump maps and skinning for scientific applications.
Case study: application of feature tracking to analysis of autoignition simulation data
Authors: Wendy S. Koegler
Published at Vis, 2001

The focus of this paper is to evaluate the usefulness of some basic feature tracking algorithms as analysis tools for combustion datasets by application to a dataset modeling autoignition. Features defined as areas of high intermediate concentrations were examined to explore the initial phases in the autoignition process.
Case study: interacting with cortical flat maps of the human brain
Authors: Monica K. Hurdal, Kevin W. Kurtz, David C. Banks
Published at Vis, 2001

The complex geometry of the human brain contains many folds and fissures, making it impossible to view the entire surface at once. Since most of the cortical activity occurs on these folds, it is desirable to be able to view the entire surface of the brain in a single view. This can be achieved using quasi-conformal flat maps of the cortical surface. Computational and visualization tools are now needed to be able to interact with these flat maps of the brain to gain information about spatial and functional relationships that might not otherwise be apparent. Such information can contribute to earlier diagnostic tools for diseases and improved treatment. Our group is developing visualization and analysis tools that will help elucidate new information about the human brain through the interaction between a cortical surface and its corresponding quasiconformal flat map.
Case study: medical Web service for the automatic 3D documentation for neuroradiological diagnosis
Authors: Sabine Iserhardt-Bauer, Peter Hastreiter, Thomas Ertl, K. Eberhardt, Bernd Tomandl
Published at Vis, 2001

The case study presents a medical Web service for the automatic analysis of CTA (computer tomography angiography) datasets. It aims at the detection and evaluation of intracranial aneurysms which are malformations of cerebral blood vessels. To obtain a standardized 3D visualization, digital videos are automatically generated. The time-consuming video production caused by the manual delineation of structures, software based volume rendering, and the interactive definition of an optimized camera path is considerably improved with a fully automatic strategy. Therefore, a previously suggested approach (C. Rezk-Salama, 2000) is applied which uses an optimized transfer function as a template and automatically adapts it to an individual dataset. Furthermore, we introduce hardware-accelerated morphologic filtering in order to detect the location of mid-size and giant aneurysms. The actual generation of the video is finally integrated into a hardware accelerated off-screen rendering process based on 3D texture mapping, ensuring fast visualization of high quality. Overall, clinical routine can be considerably assisted by providing a Web based service combining automatic detection and standardized visualization.
Case study: reconstruction, visualization and quantification of neuronal fiber pathways
Authors: Zhaohua Ding, John C. Gore, Adam W. Anderson
Published at Vis, 2001

It is of significant interest for neurological studies to determine and visualize neuronal fiber pathways in the human brain. By exploiting the capability of diffusion tensor magnetic resonance imaging to detect local orientations of neuronal fibers, we have developed a system of algorithms to reconstruct, visualize and quantify neuronal fiber pathways in vivo. Illustrative results show that the system is a promising tool for visual analysis of fiber connectivity and quantitative studies of neuronal fibers.
Case study: visual debugging of cluster hardware
Authors: Patricia Crossno, Rena A. Haynes
Published at Vis, 2001

This paper presents a novel use of visualization applied to debugging the Cplant/sup TM/ cluster hardware at Sandia National Laboratories. As commodity cluster systems grow in popularity and grow in size, tracking component failures within the hardware will become more and more difficult. We have developed a tool that facilitates visual debugging of errors within the switches and cables connecting the processors. Combining an abstract system model with color-coding for both error and job information enables failing components to be identified.
Case study: visualization of particle track data
Authors: Xiaoming Wei, Arie E. Kaufman, Timothy J. Hallman
Published at Vis, 2001

The Relativistic Heavy Ion Collider (RHIC) experiment at the Brookhaven National Lab is designed to study how the universe came into being. It is believed that after the Big Bang, the universe expanded and cooled, consisting of a soup of quarks, gluons, electrons and neutrinos. As the temperature lowered, electrons combined with protons and formed neutral atoms. Later, clouds of atoms contracted into stars. In this paper, we describe how techniques of volume rendering and information visualization are used to visualize the large particle track data set generated from this high energy physics experiment. The system, called TrackVis, is based on our earlier work of VolVis - Volume Visualization software. Example images of real particle collision data are shown, which are helpful to physicists in investigating the behavior of strongly interacting matter at high energy density.
Cell-projection of cyclic meshes
Authors: Martin Kraus, Thomas Ertl
Published at Vis, 2001

We present the first algorithm that employs hardware-accelerated cell-projection for direct volume rendering of cyclic meshes, i.e., meshes with visibility cycles. The visibility sorting of a cyclic mesh is performed by an extended topological sorting, which computes and isolates visibility cycles. Measured sorting times are comparable to previously published algorithms, which are, however, restricted to acyclic meshes. In practice, our algorithm is also useful for acyclic meshes as numerical instabilities can lead to false visibility cycles. Our method includes a simple, hardware-assisted algorithm based on image compositing that renders visibility cycles correctly. For tetrahedral meshes this algorithm allows us to render each tetrahedral cell (whether it is part of a cycle or not) by hardware-accelerated cell-projection. In its basic form our method applies only to convex cyclic meshes; however, we present an exact and a simpler but inexact extension of our method for nonconvex meshes.
Chromatin decondensation: case study of tracking features in confocal data
Authors: Wim C. de Leeuw, Robert van Liere
Published at Vis, 2001

In this case study we discuss an interactive feature tracking system and its use for the analysis of chromatin decondensation. Features are described as points in a multidimensional attribute space. Distances between points are used as a measure for feature correspondence. Users can interactively experiment with the correspondence measure in order to gain insight in chromatin movement. In addition, by defining time as an attribute, tracking problems related to noisy confocal data can be circumvented.
Circular incident edge lists: a data structure for rendering complex unstructured grids
Authors: Bruno Lévy 0001, Guillaume Caumon, Stéphane Conreaux, Xavier Cavin
Published at Vis, 2001

We present the circular incident edge lists (CIEL), a new data structure and a high-performance algorithm for generating a series of iso-surfaces in a highly unstructured grid. Slicing-based volume rendering is also considered. The CIEL data structure represents all the combinatorial information of the grid, making it possible to optimize the classical propagation from local minima paradigm. The usual geometric structures are replaced by a more efficient combinatorial structure. An active edges list is maintained, and iteratively propagated from an iso-surface to the next one in a very efficient way. The intersected cells incident to each active edge are retrieved, and the intersection polygons are generated by circulating around their facets. This latter feature enables arbitrary irregular cells to be treated, such as those encountered in certain computational fluid dynamics (CFD) simulations. Since the CIEL data structure solely depends on the connections between the cells, it is possible to take into account dynamic changes in the geometry of the mesh and in property values, which only requires the sorted extrema list to be updated. Experiments have shown that our approach is significantly faster than classical methods. The major drawback of our method is its memory consumption, higher than most classical methods. However, experimental results show that it stays within a practical range.
Compressing large polygonal models
Authors: Jeffrey Ho, Kuang-chih Lee, David J. Kriegman
Published at Vis, 2001

Presents an algorithm that uses partitioning and gluing to compress large triangular meshes which are too complex to fit in main memory. The algorithm is based largely on the existing mesh compression algorithms, most of which require an 'in-core' representation of the input mesh. Our solution is to partition the mesh into smaller submeshes and compress these submeshes separately using existing mesh compression techniques. Since a direct partition of the input mesh is out of question, instead we partition a simplified mesh and use the partition on the simplified model to obtain a partition on the original model. In order to recover the full connectivity, we present a simple scheme for encoding/decoding the resulting boundary structure from the mesh partition. When compressing large models with few singular vertices, a negligible portion of the compressed output is devoted to gluing information. On desktop computers, we have run experiments on models with millions of vertices, which could not be compressed using standard compression software packages, and have observed compression ratios as high as 17 to 1 using our technique.
Computed tomography angiography: a case study of peripheral vessel investigation
Authors: Armin Kanitsar, Rainer Wegenkittl, Petr Felkel, Dominik Fleischmann, Dominique Sandner, M. Eduard Gröller
Published at Vis, 2001

This paper deals with vessel exploration based on computed tomography angiography. Large image sequences of the lower extremities are investigated in a clinical environment. Two different approaches for peripheral vessel diagnosis dealing with stenosis and calcification detection are introduced. The paper presents an automated vessel-tracking tool for curved planar reformation. An interactive segmentation tool for bone removal is proposed.
Connectivity shapes
Authors: Martin Isenburg, Stefan Gumhold, Craig Gotsman
Published at Vis, 2001

We describe a method to visualize the connectivity graph of a mesh using a natural embedding in 3D space. This uses a 3D shape representation that is based solely on mesh connectivity: the connectivity shape. Given a connectivity, we define its natural geometry as a smooth embedding in space with uniform edge lengths and describe efficient techniques to compute it. Our main contribution is to demonstrate that a surprising amount of geometric information is implicit in the connectivity. We also show how to generate connectivity shapes that approximate given 3D shapes. Potential applications of connectivity shapes to modeling and mesh coding are described.
Continuous topology simplification of planar vector fields
Authors: Xavier Tricoche, Gerik Scheuermann, Hans Hagen
Published at Vis, 2001

Vector fields can present complex structural behavior, especially in turbulent computational fluid dynamics. The topological analysis of these data sets reduces the information, but one is usually still left with too many details for interpretation. In this paper, we present a simplification approach that removes pairs of critical points from the data set, based on relevance measures. In contrast to earlier methods, no grid changes are necessary, since the whole method uses small local changes of the vector values defining the vector field. An interpretation in terms of bifurcations underlines the continuous, natural flavor of the algorithm.
Distance-field based skeletons for virtual navigation
Authors: Ming Wan, Frank Dachille, Arie E. Kaufman
Published at Vis, 2001

We present a generic method for rapid flight planning, virtual navigation and effective camera control in a volumetric environment. Directly derived from an accurate distance from boundary (DFB) field, our automatic path planning algorithm rapidly generates centered flight paths, a skeleton, in the navigable region of the virtual environment. Based on precomputed flight paths and the DFB field, our dual-mode physically based camera control model supports a smooth, safe, and sticking-free virtual navigation with six degrees of freedom. By using these techniques, combined with accelerated volume rendering, we have successfully developed a real-time virtual colonoscopy system on low-cost PCs and confirmed the high speed, high accuracy and robustness of our techniques on more than 40 patient datasets.
Dynamic Shadow Removal from Front Projection Displays
Authors: Christopher O. Jaynes, Stephen B. Webb, R. Matt Steele, Michael S. Brown, W. Brent Seales
Published at Vis, 2001

Front-projection display environments suffer from a fundamental problem: users and other objects in the environment can easily and inadvertently block projectors, creating shadows on the displayed image. We introduce a technique that detects and corrects transient shadows in a multi-projector display. Our approach is to minimize the difference between predicted (generated) and observed (camera) images by continuous modification of the projected image values for each display device. We speculate that the general predictive monitoring framework introduced here is capable of addressing more general radiometric consistency problems. Using an automatically-derived relative position of cameras and projectors in the display environment and a straightforward color correction scheme, the system renders an expected image for each camera location. Cameras observe the displayed image, which is compared with the expected image to detect shadowed regions. These regions are transformed to the appropriate projector frames, where corresponding pixel values are increased. In display regions where more than one projector contributes to the image, shadow regions are eliminated. We demonstrate an implementation of the technique in a multiprojector system.
Efficient Adaptive Simplification of Massive Meshes
Authors: Eric Shaffer, Michael Garland
Published at Vis, 2001

The growing availability of massive polygonal models, and the inability of most existing visualization tools to work with such data, has created a pressing need for memory-efficient methods capable of simplifying very large meshes. In this paper, we present a method for performing adaptive simplification of polygonal meshes that are too large to fit in-core. Our algorithm performs two passes over an input mesh. In the first pass, the model is quantized using a uniform grid, and surface information is accumulated in the form of quadrics and dual quadrics. This sampling is then used to construct a BSP-tree in which the partitioning planes are determined by the dual quadrics. In the final pass, the original vertices are clustered using the BSP-tree, yielding an adaptive approximation of the original mesh. The BSP-tree describes a natural simplification hierarchy, making it possible to generate a progressive transmission and construct level-of-detail representations. In this way, the algorithm provides some of the features associated with more expensive edge contraction methods while maintaining greater computational efficiency. In addition to performing adaptive simplification, our algorithm exhibits output-sensitive memory requirements and allows fine control over the size of the simplified mesh.
Enridged Contour Maps
Authors: Jarke J. van Wijk, Alexandru C. Telea
Published at Vis, 2001

The visualization of scalar functions of two variables is a classic and ubiquitous application. We present a new method to visualize such data. The method is based on a nonlinear mapping of the function to a height field, followed by visualization as a shaded mountain landscape. The method is easy to implement and efficient, and leads to intriguing and insightful images: The visualization is enriched by adding ridges. Three types of applications are discussed: visualization of iso-levels, clusters (multivariate data visualization), and dense contours (flow visualization).
EWA volume splatting
Authors: Matthias Zwicker, Hanspeter Pfister, Jeroen van Baar, Markus H. Gross
Published at Vis, 2001

In this paper we present a novel framework for direct volume rendering using a splatting approach based on elliptical Gaussian kernels. To avoid aliasing artifacts, we introduce the concept of a resampling filter combining a reconstruction with a low-pass kernel. Because of the similarity to Heckbert's EWA (elliptical weighted average) filter for texture mapping we call our technique EWA volume splatting. It provides high image quality without aliasing artifacts or excessive blurring even with non-spherical kernels. Hence it is suitable for regular, rectilinear, and irregular volume data sets. Moreover, our framework introduces a novel approach to compute the footprint function. It facilitates efficient perspective projection of arbitrary elliptical kernels at very little additional cost. Finally, we show that EWA volume reconstruction kernels can be reduced to surface reconstruction kernels. This makes our splat primitive universal in reconstructing surface and volume data.
Fast detection of meaningful isosurfaces for volume data visualization
Authors: Vladimir Pekar, Rafael Wiemker, Daniel Bystrov
Published at Vis, 2001

Automatic detection of meaningful isosurfaces is important for producing informative visualizations of volume data, especially when no information about the data origin and imaging protocol is available. We propose a computationally efficient method for the automated detection of intensity transitions in volume data. In this approach, the dominant transitions correspond to clear maxima in cumulative Laplacian-weighted gray value histograms. Only one pass through the data volume is required to compute the histogram. Several other features which may be useful for exploration of data of unknown origin can be efficiently computed in a similar manner. The detected intensity transitions can be used for setting of visualization parameters for surface rendering, as well as for direct volume rendering of 3D datasets. When using surface rendering, the detected dominant intensity transition values correspond to the optimal surface isovalues for extraction of boundaries of the objects of interest. In direct volume rendering, such transitions are important for generation of the transfer functions, which are used to assign visualization properties to data voxels and determine the appearance of the rendered image. The proposed method is illustrated by examples with synthetic data as well as real biomedical datasets.