DevLan/vispubs huggingface dataset:
Pen-and-ink rendering in volume visualisation
Authors: Steve M. F. Treavett, Min Chen 0001
Published at Vis, 2000

Concerns the development of non-photorealistic rendering techniques for volume visualisation. In particular, we present two pen-and-ink rendering methods, a 3D method based on non-photorealistic solid textures, and a 2/sup +/D method that involves two rendering phases in the object space and the image space respectively. As both techniques utilize volume- and image-based data representations, they can be built upon a traditional volume rendering pipeline, and can be integrated with the photorealistic methods available in such a pipeline. We demonstrate that such an integration facilitates an effective mechanism for enhancing visualisation and its interpretation.
Polyhedral modeling
Authors: Georges-Pierre Bonneau, Stefanie Hahmann
Published at Vis, 2000

Polyhedral meshes are used for visualization, computer graphics or geometric modeling purposes and result from many applications like iso-surface extraction, surface reconstruction or CAD/CAM. The paper introduces a method for constructing smooth surfaces from a triangulated polyhedral mesh of arbitrary topology. It presents a new algorithm which generalizes and improves the triangle 4-split method (S. Hahmann and G.-P. Bonneau) in the crucial point of boundary curve network construction. This network is then filled in by a visual smooth surface from which an explicit closed form parametrization is given. Furthermore, the method becomes now completely local and can interpolate normal vector input at the mesh vertices.
Procedural annotation of uncertain information
Authors: Andrej Cedilnik, Penny Rheingans
Published at Vis, 2000

In many applications of scientific visualization, a large quantity of data is being processed and displayed in order to enable a viewer to make informed and effective decisions. Since little data is perfect, there is almost always some degree of associated uncertainty. This uncertainty is an important part of the data and should be taken into consideration when interpreting the data. Uncertainty, however, should not overshadow the data values. Many methods that address the problem of visualizing data with uncertainty can distort the data and emphasize areas with uncertain values. We have developed a method for showing the uncertainty information together with data with minimal distraction. This method uses procedurally generated annotations which are deformed according to the uncertainty information. As another possible technique we propose distorting glyphs according to the uncertainty information.
Real-time visualization of the clear-up of a former US naval base
Authors: Paul Chapman, Derek Wills, Peter Stevens, Graham R. Brookes
Published at Vis, 2000

The paper describes the effective real-time visualization of the clear-up operation of a former US nuclear submarine base, located in Holy Loch, Scotland. The Whole Field Modelling System has provided an extremely accurate real-time visualization of a large number of varying parameters such as remotely operated vehicles, cranes, barges, grabs, magnets, and detailed seabed topography. The system has improved the field staffs' spatial and temporal awareness of the underwater environment and facilitated decision-making within the complex offshore working environment.
Real-world relativity: image-based special relativistic visualization
Authors: Daniel Weiskopf, Daniel Kobras, Hanns Ruder
Published at Vis, 2000

This paper describes a novel rendering technique for special relativistic visualization. It is an image-based method which allows to render high speed flights through real-world scenes filmed by a standard camera. The relativistic effects on image generation are determined by the relativistic aberration of light, the Doppler effect, and the searchlight effect. These account for changes of apparent geometry, color and brightness of the objects. It is shown how the relativistic effects can be taken into account by a modification of the plenoptic function. Therefore, all known image-based nonrelativistic rendering methods can easily be extended to incorporate relativistic rendering. Our implementation allows interactive viewing of relativistic panoramas and the production of movies which show super-fast travel. Examples in the form of snapshots and film sequences are included.
Scanline surfacing: building separating surfaces from planar contours
Authors: David M. Weinstein
Published at Vis, 2000

A standard way to segment medical imaging datasets is by tracing contours around regions of interest in parallel planar slices. Unfortunately, the standard methods for reconstructing three dimensional surfaces from those planar contours tend to be either complicated or not very robust. Furthermore, they fail to consistently mesh abutting structures which share portions of contours. We present a novel, straight-forward algorithm for accurately and automatically reconstructing surfaces from planar contours. Our algorithm is based on scanline rendering and separating surface extraction. By rendering the contours as distinctly colored polygons and reading back each rendered slice into a segmented volume, we reduce the complex problem of building a surface from planar contours to the much simpler problem of extracting separating surfaces from a classified volume. Our scanline surfacing algorithm robustly handles complex surface topologies such as bifurcations, embedded features and abutting surfaces.
Scientific visualization of water quality in the Chesapeake bay
Authors: Robert Stein, Alan M. Shih, M. Pauline Baker, Carl F. Cerco, Mark R. Noel
Published at Vis, 2000

This paper describes our experience in designing and building a tool for visualizing the results of the CE-QUAL-ICM Three-Dimensional Eutrophication Model, as applied to water quality in the Chesapeake Bay. This model outputs a highly multidimensional dataset over very many timesteps – outstripping the capabilities of the visualization tools available to the research team. As part of the Army Engineer Research and Development Center (ERDC) Programming Environment and Training (PET) project, a special visualization tool was developed. Some problematic issues in efficiently handling and processing the data format from the computational model were resolved through this work. Also, a sophisticated system for dynamically generating visualizations of the data has been implemented. In addition, the development of the VisGen library allows for high-level, flexible control of the VTK graphics pipeline. Coupled with an easy-to-use interface to the application, this allows the user a lot of control over the graphical representation of the data. Once the user has a representation he/she is pleased with, a wide variety of options are provided for how this can be used in presentation, or for sharing with remote colleagues. This paper includes discussions on how the simulation data are handled efficiently, as well as how the issues of usability, flexibility and collaboration are addressed.
Semi-regular mesh extraction from volumes
Authors: Zoë J. Wood, Peter Schröder, David E. Breen, Mathieu Desbrun
Published at Vis, 2000

We present a novel method to extract iso-surfaces from distance volumes. It generates high quality semi-regular multiresolution meshes of arbitrary topology. Our technique proceeds in two stages. First, a very coarse mesh with guaranteed topology is extracted. Subsequently an iterative multi-scale force-based solver refines the initial mesh into a semi-regular mesh with geometrically adaptive sampling rate and good aspect ratio triangles. The coarse mesh extraction is performed using a new approach we call surface wavefront propagation. A set of discrete iso-distance ribbons are rapidly built and connected while respecting the topology of the iso-surface implied by the data. Subsequent multi-scale refinement is driven by a simple force-based solver designed to combine good iso-surface fit and high quality sampling through reparameterization. In contrast to the Marching Cubes technique our output meshes adapt gracefully to the iso-surface geometry, have a natural multiresolution structure and good aspect ratio triangles, as demonstrated with a number of examples.
Shock and vortex visualization using a combined visual/haptic interface
Authors: Dale A. Lawrence, Christopher D. Lee, Lucy Y. Pao, Roman Y. Novoselov
Published at Vis, 2000

Specific rendering modes are developed for a combined visual/haptic interface to allow exploration and understanding of fluid dynamics data. The focus is on visualization of shock surfaces and vortex cores. Advantages provided by augmenting traditional graphical rendering modes with haptic rendering modes are discussed. Particular emphasis is placed on synergistic combinations of visual and haptic modes which enable rapid, exploratory interaction with the data. Implementation issues are also discussed.
Simplification of surface annotations
Authors: Frank Suits, James T. Klosowski, William P. Horn, Gérard Lecina
Published at Vis, 2000

Geometric models are often annotated to provide additional information during visualization. Maps may be marked with rivers, roads or topographical information, and CAD data models may highlight the underlying mesh structure. While this additional information may be extremely useful, there is a rendering cost associated with it. Texture maps have often been used to convey this information at relatively low cost, but they suffer from blurring and pixelization at high magnification. We present a technique for simplifying surface annotations based on directed, asymmetric tolerance. By maintaining the annotations as geometry, as opposed to textures, we are able to simplify them while still maintaining the overall appearance of the model over a wide range of magnifications. Texture maps may still be used to provide low-resolution surface detail, such as color. We demonstrate a significant gain in rendering performance while retaining the original appearance of objects from many application domains.
Simplification of tetrahedral meshes with accurate error evaluation
Authors: Paolo Cignoni, D. Constanza, Claudio Montani, Claudio Rocchini, Roberto Scopigno
Published at Vis, 2000

The techniques for reducing the size of a volume dataset by preserving both the geometrical/topological shape and the information encoded in an attached scalar field are attracting growing interest. Given the framework of incremental 3D mesh simplification based on edge collapse, we propose an approach for the integrated evaluation of the error introduced by both the modification of the domain and the approximation of the field of the original volume dataset. We present and compare various techniques to evaluate the approximation error or to produce a sound prediction. A flexible simplification tool has been implemented, which provides a different degree of accuracy and computational efficiency for the selection of the edge to be collapsed. Techniques for preventing a geometric or topological degeneration of the mesh are also presented.
Six degree-of-freedom haptic display of polygonal models
Authors: Arthur D. Gregory, Ajith Mascarenhas, Stephen A. Ehmann, Ming C. Lin, Dinesh Manocha
Published at Vis, 2000

We present an algorithm for haptic display of moderately complex polygonal models with a six degree of freedom (DOF) force feedback device. We make use of incremental algorithms for contact determination between convex primitives. The resulting contact information is used for calculating the restoring forces and torques and thereby used to generate a sense of virtual touch. To speed up the computation, our approach exploits a combination of geometric locality, temporal coherence, and predictive methods to compute object-object contacts at kHz rates. The algorithm has been implemented and interfaced with a 6-DOF PHANToM Premium 1.5. We demonstrate its performance on force display of the mechanical interaction between moderately complex geometric structures that can be decomposed into convex primitives.
Tetrahedron based, least squares, progressive volume models with application to freehand ultrasound data
Authors: Tom Roxborough, Gregory M. Nielson
Published at Vis, 2000

We present a new method for the modeling of freehand collected three-dimensional ultrasound data. The model is piecewise linear and based upon progressive tetrahedral domains created by a subdivision scheme which splits a tetrahedron on on its longest edge and guarantees a valid tetrahedrization. Least squares error is used to characterize the model and an effective iterative technique is used to compute the values of the model at the vertices of the tetrahedral grid. Since the subdivision strategy is adaptive, the complexity of the model conforms to the complexity of the data leading to an extremely efficient and highly compressed volume model. The model is evaluated in real time using piecewise linear interpolation, and gives a medical professional the chance to see images which would not be possible using conventional ultrasound techniques.
Texturing techniques for terrain visualization
Authors: Jürgen Döllner, Konstantin Baumann, Klaus H. Hinrichs
Published at Vis, 2000

Presents a new rendering technique for processing multiple multi-resolution textures of LOD (level-of-detail) terrain models and describes its application to interactive, animated terrain content design. The approach is based on a multi-resolution model for terrain texture which cooperates with a multi-resolution model for terrain geometry. For each texture layer, an image pyramid and a texture tree are constructed. Multiple texture layers can be associated with one terrain model and can be combined in different ways, e.g. by blending and masking. The rendering algorithm simultaneously traverses the multi-resolution geometry model and the multi-resolution texture model, and takes into account geometric and texture approximation errors. It uses multi-pass rendering and exploits multi-texturing to achieve real-time performance. Applications include interactive texture lenses, texture animation and topographic textures. These techniques offer an enormous potential for developing new visualization applications for presenting, exploring and manipulating spatio-temporal data.
Topology preserving and controlled topology simplifying multiresolution isosurface extraction
Authors: Thomas Gerstner, Renato Pajarola
Published at Vis, 2000

Multiresolution methods are becoming increasingly important tools for the interactive visualization of very large data sets. Multiresolution isosurface visualization allows the user to explore volume data using simplified and coarse representations of the isosurface for overview images, and finer resolution in areas of high interest or when zooming into the data. Ideally, a coarse isosurface should have the same topological structure as the original. The topological genus of the isosurface is one important property which is often neglected in multiresolution algorithms. This results in uncontrolled topological changes which can occur whenever the level-of-detail is changed. The scope of this paper is to propose an efficient technique which allows preservation of topology as well as controlled topology simplification in multiresolution isosurface extraction.
Topology preserving compression of 2D vector fields
Authors: Suresh K. Lodha, Jose C. Renteria, Krishna M. Roskin
Published at Vis, 2000

We present an algorithm for compressing 2D vector fields that preserves topology. Our approach is to simplify the given data set using constrained clustering. We employ different types of global and local error metrics including the earth mover's distance metric to measure the degradation in topology as well as weighted magnitude and angular errors. As a result, we obtain precise error bounds in the compressed vector fields. Experiments with both analytic and simulated data sets are presented. Results indicate that one can obtain significant compression with low errors without losing topology information.
Toward a compelling sensation of telepresence: demonstrating a portal to a distant (static) office
Authors: Wei-Chao Chen, Herman Towles, Lars S. Nyland, Greg Welch, Henry Fuchs
Published at Vis, 2000

In 1998 we introduced the idea for a project we call the Office of the Future. Our long-term vision is to provide a better every-day working environment, with high-fidelity scene reconstruction for life-sized 3D tele-collaboration. In particular, we want a true sense of presence with our remote collaborator and their real surroundings. The challenges related to this vision are enormous and involve many technical tradeoffs. This is true in particular for scene reconstruction. Researchers have been striving to achieve real-time approaches, and while they have made respectable progress, the limitations of conventional technologies relegate them to relatively low resolution in a restricted volume. We present a significant step toward our ultimate goal, via a slightly different path. In lieu of low-fidelity dynamic scene modeling we present an exceedingly high fidelity reconstruction of a real but static office. By assembling the best of available hardware and software technologies in static scene acquisition, modeling algorithms, rendering, tracking and stereo projective display, we are able to demonstrate a portal to a real office, occupied today by a mannequin, and in the future by a real remote collaborator. We now have both a compelling sense of just how good it could be, and a framework into which we will later incorporate dynamic scene modeling, as we continue to head toward our ultimate goal of 3D collaborative telepresence.
Two-level volume rendering - fusing MIP and DVR
Authors: Helwig Hauser, Lukas Mroz, Gian Italo Bischi, M. Eduard Gröller
Published at Vis, 2000

Presents a two-level approach for fusing direct volume rendering (DVR) and maximum-intensity projection (MIP) within a joint rendering method. Different structures within the data set are rendered locally by either MIP or DVR on an object-by-object basis. Globally, all the results of subsequent object renderings are combined in a merging step (usually compositing in our case). This allows us to selectively choose the most suitable technique for depicting each object within the data, while keeping the amount of information contained in the image at a reasonable level. This is especially useful when inner structures should be visualized together with semi-transparent outer parts, similar to the focus-and-context approach known from information visualization. We also present an implementation of our approach which allows us to explore volumetric data using two-level rendering at interactive frame rates.
Uniform frequency images: adding geometry to images to produce space-efficient textures
Authors: Adam Hunter, Jonathan D. Cohen 0001
Published at Vis, 2000

Discusses the concept of uniform frequency images, which exhibit uniform local frequency properties. Such images make optimal use of space when sampled close to their Nyquist limit. A warping function may be applied to an arbitrary image to redistribute its local frequency content, reducing its highest frequencies and increasing its lowest frequencies in order to approach this uniform frequency ideal. The warped image may then be downsampled according to its new, reduced Nyquist limit, thereby reducing its storage requirements. To reconstruct the original image, the inverse warp is applied. We present a general, top-down algorithm to automatically generate a piecewise-linear warping function with this frequency balancing property for a given input image. The image size is reduced by applying the warp and then downsampling. We store this warped, downsampled image plus a small number of polygons with texture coordinates to describe the inverse warp. The original image is later reconstructed by rendering the associated polygons with the warped image applied as a texture map, a process which is easily accelerated by current graphics hardware. As compared to previous image compression techniques, we generate a similar graceful space-quality tradeoff with the advantage of being able to "uncompress" images during rendering. We report results for several images with sizes ranging from 15,000 to 300,000 pixels, achieving reduction rates of 70-90% with improved quality over downsampling alone.
Vector fields simplification-a case study of visualizing climate modeling and simulation data sets
Authors: Pak Chung Wong, Harlan Foote, L. Ruby Leung, Elizabeth Jurrus, Dan Adams, James J. Thomas
Published at Vis, 2000

In our study of regional climate modeling and simulation, we frequently encounter vector fields that are crowded with large numbers of critical points. A critical point in a flow is where the vector field vanishes. While these critical points accurately reflect the topology of the vector fields, in our study only a subset of them is worth further investigation. We present a filtering technique based on the vorticity of the vector fields to eliminate the less interesting and sometimes sporadic critical points in a multiresolution fashion. The neighboring regions of the preserved features, which are characterized by strong shear and circulation, are potential locations of weather instability. We apply our feature filtering technique to a regional climate modeling data set covering East Asia in the summer of 1991.
Visual cues for imminent object contact in realistic virtual environment
Authors: Helen H. Hu, Amy Ashurst Gooch, William B. Thompson, Brian E. Smits, John J. Rieser, Peter Shirley
Published at Vis, 2000

Distance judgments are difficult in current virtual environments, limiting their effectiveness in conveying spatial information. This problem is apparent when contact occurs while a user is manipulating objects. In particular, the computer graphics used to support current-generation immersive interfaces does a poor job of providing the visual cues necessary to perceive when contact between objects is about to occur. This perception of imminent contact is important in human motor control. Its absence prevents a sense of naturalness in interactive displays which allow for object manipulation. This paper reports results from an experiment evaluating the effectiveness of binocular disparity, cast shadows and diffuse inter-reflections in signaling imminent contact in a manipulation task.
Visual data fusion for applications of high-resolution numerical weather prediction
Authors: Lloyd Treinish
Published at Vis, 2000

Non-traditional applications of scientific data challenge the typical approaches to visualization. In particular popular scientific visualization strategies fail when the expertise of the data consumer is in a different field than the one that generated the data and data from the user's domain must be utilized as well. This problem occurs when predictive weather simulations are used for a number of weather-sensitive applications. A data fusion approach is adopted for visualization design and utilized for specific example problems.
Visualization of multi-dimensional data with vector-fusion
Authors: R. R. Johnson
Published at Vis, 2000

Multi-dimensional entities are modeled, displayed and understood with a new algorithm vectorizing data of any dimensionality. This algorithm is called SBP; it is a vectorized generalization of parallel coordinates. Classic geometries of any dimensionality can be demonstrated to facilitate perception and understanding of the shapes generated by this algorithm. SBP images of a 4D line, a circle and 3D and 4D spherical helices are shown. A strategy for synthesizing multi-dimensional models matching multi-dimensional data is presented. Current applications include data mining; modeling data-defined structures of scientific interest such as protein structure and Calabi-Yau figures as multi-dimensional geometric entities; generating vector-fused data signature fingerprints of classic frequency spectra that identify substances; and treating complex targets as multi-dimensional entities for automatic target recognition. SBP vector data signatures apply to all pattern recognition problems.