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Interactive Projective Texturing for Non-Photorealistic Shading of Technical 3D Models
(The Eurographics Association, 2013) Lux, Roland; Trapp, Matthias; Semmo, Amir; Döllner, Jürgen; Silvester Czanner and Wen Tang
This paper presents a novel interactive rendering technique for creating and editing shadings for man-made objects in technical 3D visualizations. In contrast to shading approaches that use intensities computed based on surface normals (e.g., Phong, Gooch, Toon shading), the presented approach uses one-dimensional gradient textures, which can be parametrized and interactively manipulated based on per-object bounding volume approximations. The fully hardware-accelerated rendering technique is based on projective texture mapping and customizable intensity transfer functions. A provided performance evaluation shows comparable results to traditional normal-based shading approaches. The work also introduce simple direct-manipulation metaphors that enables interactive user control of the gradient texture alignment and intensity transfer functions.
A Survey on Video-based Graphics and Video Visualization
(The Eurographics Association, 2011) Borgo, Rita; Chen, Min; Daubney, Ben; Grundy, Edward; Heidemann, Gunther; Höferlin, Benjamin; Höferlin, Markus; Jänicke, Heike; Weiskopf, Daniel; Xie, Xianghua; N. John and B. Wyvill
In recent years, a collection of new techniques which deal with video as input data, emerged in computer graphics and visualization. In this survey, we report the state of the art in video-based graphics and video visualization. We provide a comprehensive review of techniques for making photo-realistic or artistic computer-generated imagery from videos, as well as methods for creating summary and/or abstract visual representations to reveal important features and events in videos. We propose a new taxonomy to categorize the concepts and techniques in this newlyemerged body of knowledge. To support this review, we also give a concise overview of the major advances in automated video analysis, as some techniques in this field (e.g., feature extraction, detection, tracking and so on) have been featured in video-based modeling and rendering pipelines for graphics and visualization.
Illustrative Visualization of a Vortex Breakdown Bubble
(The Eurographics Association and Blackwell Publishing Ltd., 2011) Hummel, Mathias; Garth, Christoph; Hamann, Bernd; Hagan, Hans; Joy, Kenneth I.; Eduard Groeller and Holly Rushmeier
An Evaluation of Visualization Techniques to Illustrate Statistical Deformation Models
(The Eurographics Association and Blackwell Publishing Ltd., 2011) Caban, Jesus J.; Rheingans, Penny; Yoo, T.; H. Hauser, H. Pfister, and J. J. van Wijk
As collections of 2D/3D images continue to grow, interest in effective ways to visualize and explore the statistical morphological properties of a group of images has surged. Recently, deformation models have emerged as simple methods to capture the variability and statistical properties of a collection of images. Such models have proven to be effective in tasks such as image classification, generation, registration, segmentation, and analysis of modes of variation. A crucial element missing from most statistical models has been an effective way to summarize and visualize the statistical morphological properties of a group of images. This paper evaluates different visualization techniques that can be extended and used to illustrate the information captured by such statistical models. First, four illustration techniques are described as methods to summarize the statistical morphological properties as captured by deformation models. Second, results of a user study conducted to compare the effectiveness of each visualization technique are presented. After comparing the performance of 40 subjects, we found that statistical annotation techniques present significant benefits when analyzing the structural properties of a group of images.
Multi-modal Digitalization of Cultural Heritage Artifacts
(The Eurographics Association, 2014) Stanco, Filippo; Gallo, Giovanni; Cannata, Giovanna; Lombardo, Marcella; Andrea Giachetti
Objects made of different media, paintings, marbles, clay and wooden objects, textiles etc., form the historical collections of most of the middle to medium sized Museums in Italy. This variety poses difficult challenges to these institutions when they face the digitalization of part of their patrimony. This paper provides a report of an ongoing inter-disciplinary experimental program for a digitalization effort to be carried out by one of such institution. Through the discussion of the digitalization of different objects obtained with the use and integration of different techniques we illustrate some of the lessons learned in transferring to the final intended users the graphical tools and the know-how previously acquired in a research laboratory.
Comparative Visualization of Tracer Uptake in In Vivo Small Animal PET/CT Imaging of the Carotid Arteries
(The Eurographics Association and Blackwell Publishing Ltd., 2013) Diepenbrock, Stefan; Hermann, Sven; Schäfers, Michael; Kuhlmann, Michael; Hinrichs, Klaus; B. Preim, P. Rheingans, and H. Theisel
Cardiovascular diseases are the main cause of death in the western world. Medical research on atherosclerosis is therefore of great interest and a very active research topic. We present a visualization system that supports scientists in exploring plaque development and evaluating the applicability of PET tracers for early diagnosis of cardiovascular diseases. In our application case a cone shaped cuff has been implanted around the carotid artery of ApoE knockout mice, fed with a high cholesterol western type diet. As a result, vascular lesions develop upstream and downstream from the cuff. Tracer uptake induced by these lesions needs to be analyzed in order to evaluate the effectiveness of different PET tracers. We discuss the approach previously utilized to perform this kind of analysis, the problems arising from in vivo image acquisition (in contrast to ex vivo) and the design process of our application. In close cooperation with domain experts we have developed new visualization techniques that display PET activity in the vessel wall and surrounding tissue in a single image. We use the vessel wall detected in the CT image to perform a normalized circular projection which allows the user to judge PET signal distribution in relation to the deformed vessel. Based on this projection a quantitative analysis of a defined region adjacent to the vessel wall can be performed and compared to the artery without the cuff.
ManyLoDs: Parallel Many-View Level-of-Detail Selection for Real-Time Global Illumination
(The Eurographics Association and Blackwell Publishing Ltd., 2011) Holländer, Matthias; Ritschel, Tobias; Eisemann, Elmar; Boubekeur, Tamy; Ravi Ramamoorthi and Erik Reinhard
Level-of-Detail structures are a key component for scalable rendering. Built from raw 3D data, these structures are often defined as Bounding Volume Hierarchies, providing coarse-to-fine adaptive approximations that are well-adapted for many-view rasterization. Here, the total number of pixels in each view is usually low, while the cost of choosing the appropriate LoD for each view is high. This task represents a challenge for existing GPU algorithms. We propose ManyLoDs, a new GPU algorithm to efficiently compute many LoDs from a Bounding Volume Hierarchy in parallel by balancing the workload within and among LoDs. Our approach is not specific to a particular rendering technique, can be used on lazy representations such as polygon soups, and can handle dynamic scenes. We apply our method to various many-view rasterization applications, including Instant Radiosity, Point-Based Global Illumination, and reflection / refraction mapping. For each of these, we achieve real-time performance in complex scenes at high resolutions.
SoundRiver: Semantically-Rich Sound Illustration
(The Eurographics Association and Blackwell Publishing Ltd, 2010) Jaenicke, H.; Borgo, R.; Mason, J. S. D.; Chen, M.
Sound is an integral part of most movies and videos. In many situations, viewers of a video are unable to hear the sound track, for example, when watching it in a fast forward mode, viewing it by hearing-impaired viewers or when the plot is given as a storyboard. In this paper, we present an automated visualization solution to such problems. The system first detects the common components (such as music, speech, rain, explosions, and so on) from a sound track, then maps them to a collection of programmable visual metaphors, and generates a composite visualization. This form of sound visualization, which is referred to as SoundRiver, can be also used to augment various forms of video abstraction and annotated key frames and to enhance graphical user interfaces for video handling software. The SoundRiver conveys more semantic information to the viewer than traditional graphical representations of sound illustration, such as phonoautographs, spectrograms or artistic audiovisual animations.
Analysis of Vortex Merge Graphs
(The Eurographics Association, 2012) Kasten, Jens; Zoufahl, Andre; Hege, Hans-Christian; Hotz, Ingrid; Michael Goesele and Thorsten Grosch and Holger Theisel and Klaus Toennies and Bernhard Preim
We propose an analysis framework to investigate different flow quantities such as vorticity, λ<sub>2</sub> or the acceleration magnitude along vortex merge graphs and within their regions of influence. The explicit extraction of vortex merge graphs enables the application of statistical tools to investigate the vortex core lines themselves. The analysis tool provides common plots as scatter plots and parallel coordinates to explore the correlation of different quantities. An abstract representation of the vortex merge graph highlights birth, death and merges of vortices. Interactive picking of substructures supports a closer insepection of single vortices and their evolution. A further step integrates the regions of influence into the statistical analysis. Minima, maxima, median, mean and other percentiles of the measures along the vortex merge graph and its regions are visualized. The usability of the framework is demonstrated using a simulated flow data set of a mixing layer and a jet.
Automatic Stream Surface Seeding: A Feature Centered Approach
(The Eurographics Association and Blackwell Publishing Ltd., 2012) Edmunds, Matt; Laramee, Robert S.; Malki, Rami; Masters, Ian; Croft, Nick; Chen, Guoning; Zhang, Eugene; S. Bruckner, S. Miksch, and H. Pfister
The ability to capture and visualize information within the flow poses challenges for visualizing 3D flow fields. Stream surfaces are one of many useful integration based techniques for visualizing 3D flow. However seeding integral surfaces can be challenging. Previous research generally focuses on manual placement of stream surfaces. Little attention has been given to the problem of automatic stream surface seeding. This paper introduces a novel automatic stream surface seeding strategy based on vector field clustering. It is important that the user can define and target particular characteristics of the flow. Our framework provides this ability. The user is able to specify different vector clustering parameters enabling a range of abstraction for the density and placement of seeding curves and their associated stream surfaces. We demonstrate the effectiveness of this automatic stream surface approach on a range of flow simulations and incorporate illustrative visualization techniques. Domain expert evaluation of the results provides valuable insight into the users requirements and effectiveness of our approach.

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