EG2017
Permanent URI for this community
Browse
Browsing EG2017 by Issue Date
Now showing 1 - 20 of 55
Results Per Page
Sort Options
Item EUROGRAPHICS 2017: Education Papers Frontmatter(Eurographics Association, 2017) Bourdin, Jean Jacques; Shesh, Amit;Item Fast Flow-based Distance Quantification and Interpolation for High-Resolution Density Distributions(The Eurographics Association, 2017) Frey, Steffen; Ertl, Thomas; Adrien Peytavie and Carles BoschWe present a GPU-targeted algorithm for the efficient direct computation of distances and interpolates between high-resolution density distributions without requiring any kind of intermediate representation like features. It is based on a previously published multi-core approach, and substantially improves its performance already on the same CPU hardware due to algorithmic improvements. As we explicitly target a manycore-friendly algorithm design, we further achieve significant speedups by running on a GPU. This paper quickly reviews the previous approach, and explicitly discusses the analysis of algorithmic characteristics as well as hardware architectural considerations on which our redesign was based. We demonstrate the performance and results of our technique by means of several transitions between volume data sets.Item Partitioning Surfaces into Quad Patches(The Eurographics Association, 2017) Campen, Marcel; Adrien Bousseau and Diego GutierrezThe efficient and practical representation and processing of geometrically or topologically complex shapes often demands some form of virtual partitioning into pieces, each of which is of a simpler nature. Due to their regularity, highly structured networks of conforming quadrilateral patches, called quad layouts, or in particular instances quad meshes, are most beneficial in many scenarios; they enable the use of tensor-product representations based on NURBS or Bézier patches, grid-based multiresolution techniques, or discrete pixel-based map representations. However, partitions of this type are particularly complicated to create due to the inherent structural restrictions. Research in geometry processing has led to a variety of automatic or semi-automatic approaches to address this problem. This course provides a detailed introduction to this range of methods, treats their strengths and weaknesses, discusses their applicability and practical limitations, and outlines open problems in this field.Item Robust Blending and Occlusion Compensation in Dynamic Multi-Projection Mapping(The Eurographics Association, 2017) Lange, Vanessa; Siegl, Christian; Colaianni, Matteo; Stamminger, Marc; Bauer, Frank; Adrien Peytavie and Carles BoschUsing multi-projection systems allows us to immerse users in an altered reality without the need to wear additional head-gear. The immersion of such systems relies on the quality of the calibration which in general will degenerate over time when used outside of a lab environment. This work introduces a novel balance term that allows us to hide high frequency brightness seams caused by self-shadowing of the projected geometry and the borders of the projection frustum. We further use this more robust blending between projectors to compensate for occluding spectators, who enter the projection volume, by filling the resulting shadows with light from other projectors.Item Phong Tessellation and PN Polygons for Polygonal Models(The Eurographics Association, 2017) Hettinga, Gerben J.; Kosinka, Jiri; Adrien Peytavie and Carles BoschWe extend Phong tessellation and point normal (PN) triangles from the original triangular setting to arbitrary polygons by use of generalised barycentric coordinates and S-patches. In addition, a generalisation of the associated quadratic normal field is given as well as a simple algorithm for evaluating the polygonal extensions for a polygon with vertex normals on the GPU.Item EUROGRAPHICS 2017: Short Papers Frontmatter(Eurographics Association, 2017) Peytavie, Adrien; Bosch, Carles;Item The New CGEMS - Preparing the Computer Graphics Educational Materials Source to Meet the Needs of Educators(The Eurographics Association, 2017) Anderson, Eike Falk; Duchowski, Andrew; Liarokapis, Fotis; Redford, Adam; Jean-Jacques Bourdin and Amit SheshACM SIGGRAPH and Eurographics are restarting CGEMS, the Computer Graphics Educational Materials Source, an on-line repository of curricular material for computer graphics education. In this context, the question that we ask ourselves is: ''How can CGEMS best meet the needs of educators''? The aim of this forum is to provide the audience with an idea of the purpose of CGEMS - a source of educational materials for educators by educators - and to give them an opportunity to contribute their views and ideas towards shaping the new CGEMS. Towards this purpose, we have identified a number of issues to resolve, which the panel will put forward to the participants of the forum for discussion.Item "Synchronize" to VR Body: Full Body Illusion in VR Space(The Eurographics Association, 2017) Xiong, Peikun; Sun, Chen; Cai, Dongsheng; Adrien Peytavie and Carles BoschVirtual Reality (VR) becomes accessible to mimic a "real-like" world now. People who have a VR experience usually can be impressed by the immersive feeling, they might consider themselves are actually existed in the VR space. Self-consciousness is important for people to identify their own characters in VR space, and illusory ownership can help people to "build" their "bodies". The rubber hand illusion can convince us a fake hand made by rubber is a part of our bodies under certain circumstances. Researches about autoscopic phenomena extend this illusory to the so-called full body illusion. We conducted 3 type of experiments to study the illusory ownership in VR space as it shows in Figure 1, and we learned: Human body must receive the synchronized visual signal and somatosensory stimulus at the same time; The visual signal must be the first person perceptive; the subject and the virtual body needs to be the same height as much as possible. All these illusory ownerships accompanied by the body temperature decreases, where the body is stimulated.Item High Quality and Efficient Direct Rendering of Massive Real-world Point Clouds(The Eurographics Association, 2017) Bouchiba, Hassan; Groscot, Raphaël; Deschaud, Jean-Emmanuel; Goulette, François; Pierre Benard and Daniel SykoraWe present a novel real-time screen-space rendering algorithm for real-world 3D scanned datasets. Our method takes advantage of the pull phase of a pull-push pyramidal filling algorithm in order to feed a hidden point removal operator. The push phase is then used to fill the final framebuffer. We demonstrate on a real-world complex dataset that our method produces better visual results and is more efficient comparing to state of the art algorithms.Item EUROGRAPHICS 2017: Dirk Bartz Prize Frontmatter(Eurographics Association, 2017) Bruckner, Stefan; Ropinski, Timo;Item Swung-to-Cylinder Projection for Panoramic Image Viewing(The Eurographics Association, 2017) Chang, Che-Han; Lai, Wei-Sheng; Chuang, Yung-Yu; Pierre Benard and Daniel SykoraThis paper proposes the swung-to-cylinder projection model for mapping a sphere to a plane, which is useful for viewing 360 panoramic images. Our model extends the swung-to-plane model and consists of two steps. In the first step, the sphere is projected onto a swung surface. In the second step, the projected image on the swung surface is mapped onto a cylinder through the perspective projection. The proposed model is simple, efficient and easy to control. Similar to the swung-to-plane model, it makes a better compromise between distortion minimization and line preserving. However, it does not suffer from the distortion problem of the swung-to-plane model when viewing full 360 panoramic images.Item A Comparative Review of Tone-mapping Algorithms for High Dynamic Range Video(The Eurographics Association and John Wiley & Sons Ltd., 2017) Eilertsen, Gabriel; Mantiuk, Rafal K.; Unger, Jonas; Victor Ostromoukov and Matthias ZwickerTone-mapping constitutes a key component within the field of high dynamic range (HDR) imaging. Its importance is manifested in the vast amount of tone-mapping methods that can be found in the literature, which are the result of an active development in the area for more than two decades. Although these can accommodate most requirements for display of HDR images, new challenges arose with the advent of HDR video, calling for additional considerations in the design of tone-mapping operators (TMOs). Today, a range of TMOs exist that do support video material.We are now reaching a point where most camera captured HDR videos can be prepared in high quality without visible artifacts, for the constraints of a standard display device. In this report, we set out to summarize and categorize the research in tone-mapping as of today, distilling the most important trends and characteristics of the tone reproduction pipeline. While this gives a wide overview over the area, we then specifically focus on tone-mapping of HDR video and the problems this medium entails. First, we formulate the major challenges a video TMO needs to address. Then, we provide a description and categorization of each of the existing video TMOs. Finally, by constructing a set of quantitative measures, we evaluate the performance of a number of the operators, in order to give a hint on which can be expected to render the least amount of artifacts. This serves as a comprehensive reference, categorization and comparative assessment of the state-of-the-art in tone-mapping for HDR video.Item Generating ASCII-Art: A Nifty Assignment from a Computer Graphics Programming Course(The Eurographics Association, 2017) Anderson, Eike Falk; Jean-Jacques Bourdin and Amit SheshWe present a graphics application programming assignment from an introductory programming course with a computer graphics focus. This assignment involves simple image-processing, asking students to write a conversion program that turns images into ASCII Art. Assessment of the assignment is simplified through the use of an interactive grading tool.Item bRenderer: A Flexible Basis for a Modern Computer Graphics Curriculum(The Eurographics Association, 2017) Bürgisser, Benjamin; Steiner, David; Pajarola, Renato; Jean-Jacques Bourdin and Amit SheshIn this article, we present bRenderer, a basic educational 3D rendering framework that has resulted from four years of experience in teaching an introductory-level computer graphics course at the University of Zurich. Our renderer is based on the observation that teaching a single basic but comprehensive computer graphics course often means to face the choice between students learning a low-level graphics API bottom-up on one side, or a powerful (game) engine on the other. Solutions between these two extremes tend to be either too rudimentary to easily allow advanced visual effects in student projects, or too abstract to facilitate learning about the underlying principles of computer graphics. Our platform-independent framework abstracts the functionality of its underlying graphics API and libraries to an extent that still preserves the main concepts taught in a computer graphics course. Consequently, bRenderer can be used in student projects, as well as in exercises. It helps students to easily understand how a renderer is implemented without getting distracted by the particular implementation of the framework or platform-specific characteristics.Item Proxy Clouds for RGB-D Stream Processing: A Preview(The Eurographics Association, 2017) Kaiser, Adrien; Zepeda, José Alonso Ybanez; Boubekeur, Tamy; Pierre Benard and Daniel SykoraModern consumer depth cameras are widely used for 3D capture in indoor environments, for applications such as modeling, robotics or gaming. Nevertheless, their use is limited by their low resolution, with frames often corrupted with noise, missing data and temporal inconsistencies. In order to cope with all these issues, we present Proxy Clouds, a multiplanar superstructure for real-time processing of RGB-D data. By generating a single set of planar proxies from raw RGB-D data and updating it through time, several processing primitives can be applied to improve the quality of the RGB-D stream or lighten further operations. We illustrate the use of Proxy Clouds on several applications, including noise and temporal flickering removal, hole filling, resampling, color processing and compression. We present experiments performed with our framework in indoor scenes of different natures captured with a consumer depth sensor.Item State of the Art in Methods and Representations for Fabrication-Aware Design(The Eurographics Association and John Wiley & Sons Ltd., 2017) Bermano, Amit Haim; Funkhouser, Thomas; Rusinkiewicz, Szymon; Victor Ostromoukov and Matthias ZwickerComputational manufacturing technologies such as 3D printing hold the potential for creating objects with previously undreamed-of combinations of functionality and physical properties. Human designers, however, typically cannot exploit the full geometric (and often material) complexity of which these devices are capable. This STAR examines recent systems developed by the computer graphics community in which designers specify higher-level goals ranging from structural integrity and deformation to appearance and aesthetics, with the final detailed shape and manufacturing instructions emerging as the result of computation. It summarizes frameworks for interaction, simulation, and optimization, as well as documents the range of general objectives and domain-specific goals that have been considered. An important unifying thread in this analysis is that different underlying geometric and physical representations are necessary for different tasks: we document over a dozen classes of representations that have been used for fabrication-aware design in the literature. We analyze how these classes possess obvious advantages for some needs, but have also been used in creative manners to facilitate unexpected problem solutions.Item Conformal Factor Persistence for Fast Hierarchical Cone Extraction(The Eurographics Association, 2017) Vintescu, Ana-Maria; Dupont, Florent; Lavoué, Guillaume; Memari, Pooran; Tierny, Julien; Adrien Peytavie and Carles BoschThis paper presents a new algorithm for the fast extraction of hierarchies of cone singularities for conformal surface parameterization. Cone singularities have been shown to greatly improve the distortion of such parameterizations since they locally absorb the area distortion. Therefore, existing automatic approaches aim at inserting cones where large area distortion can be predicted. However, such approaches are iterative, which results in slow computations, even often slower than the actual subsequent parameterization procedure. This becomes even more problematic as often the user does not know in advance the right number of needed cones and thus needs to explore cone hierarchies to obtain a satisfying result. Our algorithm relies on the key observation that the local extrema of the conformal factor already provide a good approximation of the cone singularities extracted with previous techniques, while needing only one linear solving where previous approaches needed one solving per hierarchy level. We apply concepts from persistent homology to organize very efficiently such local extrema into a global hierarchy. Experiments demonstrate the approximation quality of our approach quantitatively and report time-performance improvements of one order of magnitude, which makes our technique well suited for interactive contexts.Item Visual Analytics for Digital Radiotherapy: Towards a Comprehensible Pipeline(The Eurographics Association, 2017) Raidou, Renata G.; Breeuwer, Marcel; Vilanova, Anna; Stefan Bruckner and Timo RopinskiProstate cancer is one of the most frequently occurring types of cancer in males. It is often treated with radiation therapy, which aims at irradiating tumors with a high dose, while sparing the surrounding healthy tissues. In the course of the years, radiotherapy technology has undergone great advancements. However, tumors are not only different from each other, they are also highly heterogeneous within, consisting of regions with distinct tissue characteristics, which should be treated with different radiation doses. Tailoring radiotherapy planning to the specific needs and intra-tumor tissue characteristics of each patient is expected to lead to more effective treatment strategies. Currently, clinical research is moving towards this direction, but an understanding of the specific tumor characteristics of each patient, and the integration of all available knowledge into a personalizable radiotherapy planning pipeline are still required. The present work describes solutions from the field of Visual Analytics, which aim at incorporating the information from the distinct steps of the personalizable radiotherapy planning pipeline, along with eventual sources of uncertainty, into comprehensible visualizations. All proposed solutions are meant to increase the - up to now, limited - understanding and exploratory capabilities of clinical researchers. These approaches contribute towards the interactive exploration, visual analysis and understanding of the involved data and processes at different steps of the radiotherapy planning pipeline, creating a fertile ground for future research in radiotherapy planning.Item AIR: Anywhere Immersive Reality with User-Perspective Projection(The Eurographics Association, 2017) Byun, JungHyun; Chae, SeungHo; Yang, YoonSik; Han, TackDon; Adrien Peytavie and Carles BoschProjection-based augmented reality (AR) has much potential, but is limited in that it requires burdensome installations and prone to geometric distortions on display surface. To overcome these limitations, we propose AIR. It can be carried and placed anywhere to project AR using pan/tilting motors, while providing the user with distortion-free projection of a correct 3D view.Item Physically-based Muscles and Fibers Modeling from Superficial Patches(The Eurographics Association, 2017) Turchet, Fabio; Fryazinov, Oleg; Schvartzman, Sara C.; Adrien Peytavie and Carles BoschWe propose a novel approach for the generation of volumetric muscle primitives and their associated fiber field, suitable for simulation in computer animation. Muscles are notoriously difficult to sculpt because of their complex shapes and fiber architecture, therefore often requiring trained artists to render anatomical details. Moreover, physics simulation requires these geometries to be modeled in an intersection-free rest state and to have a spatially-varying fiber field to support contraction with anisotropic material models. Inspired by the principles of computational design, we satisfy these requirements by generating muscle primitives automatically, complete with tendons and fiber fields, using physics based simulation of inflatable 3D patches which are user-defined on the external mesh of a character.