EG2010

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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.
Designing Multi-projector VR Systems: From Bits to Bolts
(The Eurographics Association, 2010) Soares, Luciano Pereira; Jorge, Joaquim A.; Dias, José Miguel Salles; Raposo, Alberto; Araújo, Bruno R. de; U. Assarsson and D. Weiskopf
This tutorial will present how to design, construct and manage immersive multi-projection environments, covering everything from projection technologies to computer hardware and software integration. Topics as tracking, multimodal interactions and audio are going to be explored. At the end, we are going to present important design decisions from real cases. <br> The objective of this tutorial is to give an introduction to the issues to consider when planning the installation of a multi-projection environment for researchers and professionals in the computer graphics and virtual reality field. No previous knowledge is necessary in the audience for the tutorial, except for basic knowledge of computer graphics and virtual reality.
A Film Balloon Design System Integrated with Shell Element Simulation
(The Eurographics Association, 2010) Furuta, Yohsuke; Umetani, Nobuyuki; Mitani, Jun; Igarashi, Takeo; Fukui, Yukio; H. P. A. Lensch and S. Seipel
CAD systems that have user-friendly interfaces for assisting ordinary people to design objects is becoming common. Most of these systems combine a sketch interface with physical simulation. In this paper, we propose a system for designing balloons made of non-stretchy material such as aluminum foil, plastic film and paper. We implemented the system by using a finite element method that is based on discrete Kirchhoff triangle (DKT) shell elements and a sketch interface that enables users to easily design the realistic shape of an inflated balloon. The 2D pattern for the balloon design is generated automatically by our system. We evaluated our system by a user study with six elementary school children and their parents. These users designed target objects and responded to a questionnaire.
Scalable Height Field Self-Shadowing
(The Eurographics Association and Blackwell Publishing Ltd, 2010) Timonen, Ville; Westerholm, Jan
We present a new method suitable for general purpose graphics processing units to render self-shadows on dynamic height fields under dynamic light environments in real-time. Visibility for each point in the height field is determined as the exact horizon for a set of azimuthal directions in time linear in height field size and the number of directions. The surface is shaded using the horizon information and a high-resolution light environment extracted on-line from a high dynamic range cube map, allowing for detailed extended shadows. The desired accuracy for any geometric content and lighting complexity can be matched by choosing a suitable number of azimuthal directions. Our method is able to represent arbitrary features of both high- and low-frequency, unifying hard and soft shadowing. We achieve 23 fps on 1024x1024 height fields with 64 azimuthal directions under a 256x64 environment lighting on an Nvidia GTX 280 GPU.
Ray Tracing using Hierarchies of Slab Cut Balls
(The Eurographics Association, 2010) Källberg, Linus; Larsson, Thomas; H. P. A. Lensch and S. Seipel
In this paper, bounding volume trees of slab cut balls are evaluated and compared with other types of trees for ray tracing. A novel tree construction algorithm is proposed, which utilizes a relative orientation heuristic between parent and child nodes. Also, a fast intersection test between a ray and a slab cut ball is presented. Experimental comparisons to other commonly used enclosing shapes reveal that the slab cut ball is attractive. In particular, the slab cut ball outperforms the sphere in all tested scenes with speed-up factors between 1 and 4.
The Virtual Director: a Correlation-Based Online Viewing of Human Motion
(The Eurographics Association and Blackwell Publishing Ltd, 2010) Assa, J.; Wolf, L.; Cohen-Or, D.
Automatic camera control for scenes depicting human motion is an imperative topic in motion capture base animation, computer games, and other animation based fields. This challenging control problem is complex and combines both geometric constraints, visibility requirements, and aesthetic elements. Therefore, existing optimization-based approaches for human action overview are often too demanding for online computation.In this paper, we introduce an effective automatic camera control which is extremely efficient and allows online performance. Rather than optimizing a complex quality measurement, at each time it selects one active camera from a multitude of cameras that render the dynamic scene. The selection is based on the correlation between each view stream and the human motion in the scene. Two factors allow for rapid selection among tens of candidate views in real-time, even for complex multi-character scenes: the efficient rendering of the multitude of view streams, and optimized calculations of the correlations using modified CCA. In addition to the method s simplicity and speed, it exhibits good agreement with both cinematic idioms and previous human motion camera control work. Our evaluations show that the method is able to cope with the challenges put forth by severe occlusions, multiple characters and complex scenes.
3D Isocontours Real-time Generation and Visualization of 3D Stepped Terrain Models
(The Eurographics Association, 2010) Glander, Tassilo; Trapp, Matthias; Döllner, Jürgen; H. P. A. Lensch and S. Seipel
Isocontours (also isopleths, isolines, level sets) are commonly used to visualize real-valued data defined over a 2D plane according to a set of given isovalues. To support the 3D landscape metaphor for information visualization, a 3D stepped terrain can be derived by lifting and extruding isolines to their particular isovalue, but typically requires triangulation of the resulting surface representation in a preprocessing step. We present a concept and rendering technique for triangle-based terrain models that provide interactive, adaptive generation and visualization of such stepped terrains without preprocessing. Our fully hardware-accelerated rendering technique creates additional step geometry for each triangle intersecting an iso-plane on-the-fly. Further, an additional interpolation schema facilitates smooth transition between established 3D terrain visualization and its stepped variant.
Interactive 3D Stereoscopic Dome with Automatic Calibration
(The Eurographics Association, 2010) Dingeldey, Felix; Schiewe, Manuel; Gerhardt, Jérémie; Ahlers, Kay-Ingo; Haulsen, Ivo; Matthew Cooper and Kari Pulli
In recent years, the advances in projection technology and the increasing rendering capacity of modern computers allowed the development of immersive digital domes. Digital dome systems are not limited to planetariums, but also find their way into science centers, theme parks, or multimedia events. However, most installations do not support 3D stereoscopic display, because of the difficulties the curved projection surface implies. In this paper, we present both the construction of a small 3D stereoscopic dome and a versatile multi-projector system that exploits the capabilities digital technology offers today. Our system performs automatic geometric and color projector calibration as well as soft-edge blending. Moreover, it implements real time media compositing, which allows enhancing dome viewing experiences and going beyond the simple playout of pre-rendered content by enabling user interaction.
Fast High-Dimensional Filtering Using the Permutohedral Lattice
(The Eurographics Association and Blackwell Publishing Ltd, 2010) Adams, Andrew; Baek, Jongmin; Davis, Myers Abraham
Many useful algorithms for processing images and geometry fall under the general framework of high-dimensional Gaussian filtering. This family of algorithms includes bilateral filtering and non-local means. We propose a new way to perform such filters using the permutohedral lattice, which tessellates high-dimensional space with uniform simplices. Our algorithm is the first implementation of a high-dimensional Gaussian filter that is both linear in input size and polynomial in dimensionality. Furthermore it is parameter-free, apart from the filter size, and achieves a consistently high accuracy relative to ground truth (> 45 dB). We use this to demonstrate a number of interactive-rate applications of filters in as high as eight dimensions.
Bidirectional Search for Interactive Motion Synthesis
(The Eurographics Association and Blackwell Publishing Ltd, 2010) Lo, Wan-Yen; Zwicker, Matthias
We present an approach to improve the search efficiency for near-optimal motion synthesis using motion graphs. An optimal or near-optimal path through a motion graph often leads to the most intuitive result. However, finding such a path can be computationally expensive. Our main contribution is a bidirectional search algorithm. We dynamically divide the search space evenly and merge two search trees to obtain the final solution. This cuts the maximum search depth almost in half and leads to significant speedup. To illustrate the benefits of our approach, we present an interactive sketching interface that allows users to specify complex motions quickly and intuitively.
Segmental Brush Synthesis with Stroke Images
(The Eurographics Association, 2010) Ando, Ryoichi; Tsuruno, Reiji; H. P. A. Lensch and S. Seipel
We present a new approach for synthesizing realistic brush strokes exploiting recent works of texture synthesis from stroke images. (See Figure 1). In our method, stroke images are automatically decomposed into a sequence of quad segments and stitched together along the path of user s input to produce final image. Numbers of methods using textures on digital painting have been explored; our usage of texture is novel in that the source image is typically a photo and the synthesis is fast enough to achieve realtime feedback. In contrast to previous methods, our approach allows a large variety of artistic brushes to be interactively simulated fairly so that unique media which haven t caught attention yet such as lipsticks or finger paint, are well reproduced. We shall show some artworks created using our method and demonstrate feasibility of our algorithm.We present a new approach for synthesizing realistic brush strokes exploiting recent works of texture synthesis from stroke images. (See Figure 1). In our method, stroke images are automatically decomposed into a sequence of quad segments and stitched together along the path of user s input to produce final image. Numbers of methods using textures on digital painting have been explored; our usage of texture is novel in that the source image is typically a photo and the synthesis is fast enough to achieve realtime feedback. In contrast to previous methods, our approach allows a large variety of artistic brushes to be interactively simulated fairly so that unique media which haven t caught attention yet such as lipsticks or finger paint, are well reproduced. We shall show some artworks created using our method and demonstrate feasibility of our algorithm.We present a new approach for synthesizing realistic brush strokes exploiting recent works of texture synthesis from stroke images. (See Figure 1). In our method, stroke images are automatically decomposed into a sequence of quad segments and stitched together along the path of user s input to produce final image. Numbers of methods using textures on digital painting have been explored; our usage of texture is novel in that the source image is typically a photo and the synthesis is fast enough to achieve realtime feedback. In contrast to previous methods, our approach allows a large variety of artistic brushes to be interactively simulated fairly so that unique media which haven t caught attention yet such as lipsticks or finger paint, are well reproduced. We shall show some artworks created using our method and demonstrate feasibility of our algorithm.
Advanced Material Appearance Models
(The Eurographics Association, 2010) Dorsey, Julie; Rushmeier, Holly; U. Assarsson and D. Weiskopf
This tutorial will cover the foundational elements of advanced material appearance models. For many years appearance models in computer graphics focused on general models for reflectance functions coupled with texture maps. However, even very common materials such as hair, skin, fabric, and rusting metal require more sophisticated models to appear realistic. In the tutorial we will begin by briefly reviewing basic reflectance models and the use of texture maps. We will then describe some common themes in advanced material models that include combining the effects of layers, groups of particles and or fibers. We will survey the detailed models necessary needed to model materials such as (but not limited to) skin (including pigmentation, pores, subsurface scattering), plants (including internal structure affecting scattering and characteristic shapes) and paints (including color flop and sparkle effects in automotive paints). In the next section of the tutorial we will treat the modeling of complex appearance due to aging and weathering processes. A general taxonomy of these effects will be presented, as well as methods to simulate and to capture these effects. The tutorial will close with a look at current trends in material modeling research. Important new trends include new interfaces for modeling materials, insights into material perception, and the availability of code and data for material models.
Deformation Transfer to Multi-Component Objects
(The Eurographics Association and Blackwell Publishing Ltd, 2010) Zhou, Kun; Xu, Weiwei; Tong, Yiying; Desbrun, Mathieu
We present a simple and effective algorithm to transfer deformation between surface meshes with multiple components. The algorithm automatically computes spatial relationships between components of the target object, builds correspondences between source and target, and finally transfers deformation of the source onto the target while preserving cohesion between the target s components. We demonstrate the versatility of our approach on various complex models.
Rendering Wave Effects with Augmented Light Field
(The Eurographics Association and Blackwell Publishing Ltd, 2010) Oh, Se Baek; Kashyap, Sriram; Garg, Rohit; Chandran, Sharat; Raskar, Ramesh
Ray-based representations can model complex light transport but are limited in modeling diffraction effects that require the simulation of wavefront propagation. This paper provides a new paradigm that has the simplicity of light path tracing and yet provides an accurate characterization of both Fresnel and Fraunhofer diffraction. We introduce the concept of a light field transformer at the interface of transmissive occluders. This generates mathematically sound, virtual, and possibly negative-valued light sources after the occluder. From a rendering perspective the only simple change is that radiance can be temporarily negative. We demonstrate the correctness of our approach both analytically, as well by comparing values with standard experiments in physics such as the Young s double slit. Our implementation is a shader program in OpenGL that can generate wave effects on arbitrary surfaces.
Mesh Snapping: Robust Interactive Mesh Cutting Using Fast Geodesic Curvature Flow
(The Eurographics Association and Blackwell Publishing Ltd, 2010) Zhang, Juyong; Wu, Chunlin; Cai, Jianfei; Zheng, Jianmin; Tai, Xue-cheng
This paper considers the problem of interactively finding the cutting contour to extract components from a given mesh. Some existing methods support cuts of arbitrary shape but require careful and tedious input from the user. Others need little user input however they are sensitive to user input and need a postprocessing step to smooth the generated jaggy cutting contours. The popular geometric snake can be used to optimize the cutting contour, but it cannot deal with the topology change. In this paper, we propose a geodesic curvature flow based framework to overcome all these problems. Since in many cases the meaningful cutting contour on a 3D mesh is locally shortest in the sense of some weighted curve length, the geodesic curvature flow is an ideal tool for our problem. It evolves the cutting contour to the nearby local minimum. We should mention that the previous numerical scheme, discretized geodesic curvature flow (dGCF) is too slow and has not been applied to mesh segmentation. With a careful observation to dGCF, we devise here a fast computation scheme called fast geodesic curvature flow (FGCF), which only needs to solve a smaller and easier problem. The initial cutting contour is generated by a variant of random walks algorithm, which is very fast and gives reasonable cutting result with little user input. Experiment results on the benchmark mesh segmentation data set show that our proposed framework is robust to user input and capable of producing good results reflecting geometric features and human shape perception.
BetweenIT: An Interactive Tool for Tight Inbetweening
(The Eurographics Association and Blackwell Publishing Ltd, 2010) Whited, Brian; Noris, Gioacchino; Simmons, Maryann; Sumner, Robert W.; Gross, Markus; Rossignac, Jarek
The generation of inbetween frames that interpolate a given set of key frames is a major component in the production of a 2D feature animation. Our objective is to considerably reduce the cost of the inbetweening phase by offering an intuitive and effective interactive environment that automates inbetweening when possible while allowing the artist to guide, complement, or override the results. Tight inbetweens, which interpolate similar key frames, are particularly time-consuming and tedious to draw. Therefore, we focus on automating these high-precision and expensive portions of the process. We have designed a set of user-guided semi-automatic techniques that fit well with current practice and minimize the number of required artist-gestures. We present a novel technique for stroke interpolation from only two keys which combines a stroke motion constructed from logarithmic spiral vertex trajectories with a stroke deformation based on curvature averaging and twisting warps. We discuss our system in the context of a feature animation production environment and evaluate our approach with real production data.
Intelligent Games for Education - An Intention Monitoring Approach based on Dynamic Bayesian Network
(The Eurographics Association, 2010) Cheng, Irene; Chen, Feng; Rodrigues, Saul Daniel; Pañella, Oscar Garcia; Vicent, Lluis; Basu, Anup; L. Kjelldahl and G. Baronoski
Computer games have become one of the preferred choices for entertainment in our society primarily because they are interactive, have appealing multimedia content, and provide an immersive and rewarding environment for players. These qualities constitute an essential psychophysical factor that inspires learning abilities and new knowledge. Despite all these promising elements, studies have shown that current educational games are not as effective as they could be. A lack of adaptive tutoring and feedback tools, lack of proper knowledge assessment, and weakly designed gameplay are the major factors for their inefficiency.We address these problems by proposing an Intelligent Tutoring System (ITS) for computer games. An important contribution of this ITS is its capability to track player intentions and award partial marks, which provides more accurate assessment than simply giving full mark to the correct result and none to an incorrect answer. Two strategies adopted in this system are Bayesian Networks based student modeling and individualized tutoring. The system can incorporate one or more games and can address one or more educational topic. The information collected from student interaction with computer games is used to update a student module that reports a student s current level of knowledge, making adaptive tutoring and assessment with computer games more effective. In order to provide an engaging and interactive environment, each game in the system has a local student module constructed based on a Dynamic Bayesian Network. We describe the design and evaluation of our ITS using a prototype implementation with several game examples. Positive evaluation results support the feasibility of the proposed system.
Improved Variational Guiding of Smoke Animations
(The Eurographics Association and Blackwell Publishing Ltd, 2010) Nielsen, Michael B.; Christensen, Brian B.
Smoke animations are hard to art-direct because simple changes in parameters such as simulation resolution often lead to unpredictable changes in the final result. Previous work has addressed this problem with a guiding approach which couples low-resolution simulations - that exhibit the desired flow and behaviour - to the final, high-resolution simulation. This is done in such a way that the desired low frequency features are to some extent preserved in the high-resolution simulation. However, the steady (i.e. constant) guiding used often leads to a lack of sufficiently high detail, and employing time-dependent guiding is expensive because the matrix of the resulting set of equations needs to be recomputed at every iteration. We propose an improved mathematical model for Eulerian-based simulations which is better suited for dynamic, time-dependent guiding of smoke animations through a novel variational coupling of the low- and high-resolution simulations. Our model results in a matrix that does not require re-computation when the guiding changes over time, and hence we can employ time-dependent guiding more efficiently both in terms of storage and computational requirements. We demonstrate that time-dependent guiding allows for more high frequency detail to develop without losing correspondence to the low resolution simulation. Furthermore, we explore various artistic effects made possible by time-dependent guiding.
Image Statistics and their Applications in Computer Graphics
(The Eurographics Association, 2010) Pouli, T.; Cunningham, D. W.; Reinhard, E.; Helwig Hauser and Erik Reinhard
The statistics of natural images have attracted the attention of researchers in a variety of fields and have been used as a means to better understand the human visual system and its processes. A number of algorithms in computer graphics, vision and image processing take advantage of such statistical findings to create visually more plausible results. With this report we aim to review the state of the art in image statistics and discuss existing and potential applications within computer graphics and related areas.
Towards an Academic Praxis for Domed Virtual Environments
(The Eurographics Association, 2010) Carss, Peter; Matthew Cooper and Kari Pulli
This paper sets out the current state of activities for the domed virtual environment located within the University of Plymouth, UK. Some of these activities have arisen through reactions to demands on the dome. Some, particularly those concerning students education, have arisen by design. The paper describes the theoretical frameworks, curricula, methodologies and tools that have emerged, and suggests that these are first steps towards what might be termed a praxis of domed virtual environments.

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