IEEE VIS Publication Dataset

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.

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.

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.

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.

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.

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. 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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 interreflections in signaling imminent contact in a manipulation task.