23-Issue 4
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Item 25th EUROGRAPHICS General Assembly(The Eurographics Association and Blackwell Publishing Ltd., 2004)Item ACM/EG Symposium on Computer Animation 2004(The Eurographics Association and Blackwell Publishing Ltd., 2004) Boulic, Ronan; Pai, Dinesh K.; Badler, Norman; Desbrun, Mathieu; Reveret, LionelItem Author Index Volume 23 (2004)(The Eurographics Association and Blackwell Publishing Ltd., 2004)Item Compression of Large-Scale Terrain Data for Real-Time Visualization Using a Tiled Quad Tree(The Eurographics Association and Blackwell Publishing Ltd., 2004) Platings, M.; Day, A. M.The aim of the rapid world modeling project is to implement a system to visualize the topography of the entire world on consumer-level hardware. This presents a significant problem in terms of both storage requirements and rendering speed. This paper presents the a??Tiled Quad Treea??, a technique and format for the storage of digital terrain models, to work as part of an integrated system for the visualization of global terrain data. We show how this format efficiently stores and compresses elevation data, in a way that allows the data to be read very rapidly from hard disk or similar storage medium, to facilitate real-time rendering. The results of compressing several distinct data sets are presented.Item Editorial(2004) David Duke; Roberto ScopignoItem EG/IEEE Symposium on Point-Based Graphics(The Eurographics Association and Blackwell Publishing Ltd., 2004) Keiser, RichardItem Eurographics Symposium on Rendering(The Eurographics Association and Blackwell Publishing Ltd., 2004) Ollila, MarkItem Fast Hybrid Approach for Texturing Point Models(The Eurographics Association and Blackwell Publishing Ltd., 2004) Haitao Zhang; Feng Qiu; Arie KaufmanWe present three methods for texturing point models from sample textures. The first method, the point parameterization method, uses a fast distortion-bounded parameterization algorithm to flatten the point model's surface into one or more 2D patches. The sample texture is mapped onto these patches and alpha blending is used to minimize the discontinuity in the gaps between the patches. The second method is based on neighborhood matching where a color is assigned to each point by searching the best match within an irregular neighborhood. The hybrid method combines the former two methods, capitalizing on the advantages of both. The point parameterization method is used first to color most of the points, and the point neighborhood-matching method is then applied to the points belonging to the gaps between the parameterized patches to minimize the discontinuity. We opt for fast texture generation, while some discontinuities may appear in the gaps of anisotropic textures.Item Graphics Hardware 2004(The Eurographics Association and Blackwell Publishing Ltd., 2004) Doggett, Michael; Lastra, AnselmoItem New Eurographics Fellows(The Eurographics Association and Blackwell Publishing Ltd., 2004)Item Para-Graph: Graph-Based Parameterization of Triangle Meshes with Arbitrary Genus(The Eurographics Association and Blackwell Publishing Ltd., 2004) Giuseppe Patane; Michela Spagnuolo; Bianca FalcidienoThis paper describes a novel approach to the parameterization of triangle meshes representing 2-manifolds with an arbitrary genus. A topology-based decomposition of the shape is computed and used to segment the shape into primitives, which define a chart decomposition of the mesh. Then, each chart is parameterized using an extension of the barycentric coordinates method. The charts are all 0-genus and can be of three types only, depending on the number of boundary components. The chart decomposition and the parameterization are used to define a shape graph where each node represents one primitive and the arcs code the adjacency relationships between the primitives. Conical and cylindrical primitives are coded together with their skeletal lines that are computed from and aligned with their parameterization. The application of the parameterization approach to remeshing guarantees that extraordinary vertices are localized only where two patches share a boundary and they are not scattered on the whole surface.Item Physical Validation of Global Illumination Methods: Measurement and Error Analysis(The Eurographics Association and Blackwell Publishing Ltd., 2004) Roland Schregle; Jan WienoldIn this paper, we present a physical validation of global illumination algorithms based on measurements from a simple experimental setup. The validation methodology emphasizes tractability and error minimization. To this end, we discuss issues such as the acquisition and accurate simulation of material bidirectional reflection distribution functions (BRDFs) and the light source distribution, as well as error analysis. In addition, we present a nearest-neighbor resampling technique for BRDFs and a simple method for extracting the light source distribution from digitized high dynamic range (HDR) images. Finally, we compare the measurements to a forward and backward raytracing solution (photon map and RADIANCE, respectively) in a set of case studies.Item Placement of Deformable Objects(The Eurographics Association and Blackwell Publishing Ltd., 2004) S. Schein; G. ElberWith the increasing complexity of photorealistic scenes, the question of building and placing objects in three-dimensional scenes is becoming ever more difficult. While the question of placement of rigid objects has captured the attention of researchers in the past, this work presents an intuitive and interactive scheme to properly place deformable objects with the aid of free-form deformation tools. The presented scheme can also be used to animate the locomotion of nonrigid objects, most noticeably animals, and adapt the motion to arbitrary terrain. The automatic construction of our free-form deformation tool is completely hidden from the end user, and hence, circumvents the difficulties typically faced in manipulating these deformation functions. Further, a precise bound on the error that is introduced by applying free-form deformations to polygonal models is presented, along with an almost-optimal adaptive refinement algorithm to achieve a certain accuracy in the mapping.Item REPORT OF THE STATUTORY AUDITORS TO THE GENERAL MEETING OF THE MEMBERS OF EUROGRAPHICS ASSOCIATION GENEVA(The Eurographics Association and Blackwell Publishing Ltd., 2004)Item Second Symposium on Geometry Processing(The Eurographics Association and Blackwell Publishing Ltd., 2004) Scopigno, Roberto; Zorin, Denis; Alliez, Pierre; Boissonnat, Jean-DanielItem Siggraph 2004(The Eurographics Association and Blackwell Publishing Ltd., 2004) Laycock, S. D.; Laycock, R. G.; Ryder, G.; Juarez-Comboni, J.; Montes de Oca, C.Item SIMD Optimization of Linear Expressions for Programmable Graphics Hardware(The Eurographics Association and Blackwell Publishing Ltd., 2004) Chandrajit Bajaj; Insung Ihm; Jungki Min; Jinsang OhThe increased programmability of graphics hardware allows efficient graphical processing unit (GPU) implementations of a wide range of general computations on commodity PCs. An important factor in such implementations is how to fully exploit the SIMD computing capacities offered by modern graphics processors. Linear expressions in the form of , where A is a matrix, and and are vectors, constitute one of the most basic operations in many scientific computations. In this paper, we propose a SIMD code optimization technique that enables efficient shader codes to be generated for evaluating linear expressions. It is shown that performance can be improved considerably by efficiently packing arithmetic operations into four-wide SIMD instructions through reordering of the operations in linear expressions. We demonstrate that the presented technique can be used effectively for programming both vertex and pixel shaders for a variety of mathematical applications, including integrating differential equations and solving a sparse linear system of equations using iterative methods.Item Smooth Surface Reconstruction Using Tensor Fields as Structuring Elements(The Eurographics Association and Blackwell Publishing Ltd., 2004) Vieira, M. B.; Martins, P. P.; Araujo, A. A.; Cord, M.; Philipp-Foliguet, S.We propose a new strategy to estimate surface normal information from highly noisy sparse data. Our approach is based on a tensor field morphologically adapted to infer normals. It acts as a three-dimensional structuring element of smooth surfaces. Robust orientation inference for all input elements is performed by morphological operations using the tensor field. A general normal estimator is defined by combining the inferred normals, their confidences and the tensor field. This estimator can be used to directly reconstruct the surface or give input normals to other reconstruction methods. We present qualitative and quantitative results to show the behavior of the original methods and ours. A comparative discussion of these results shows the efficiency of our propositions.Item Stellar Mesh Simplification Using Probabilistic Optimization(The Eurographics Association and Blackwell Publishing Ltd., 2004) Antonio W. Vieira; Thomas Lewiner; Luiz Velho; Helio Lopes; Geovan TavaresItem Style-Based Motion Synthesis(The Eurographics Association and Blackwell Publishing Ltd., 2004) Raquel Urtasun; Pascal Glardon; Ronan Boulic; Daniel Thalmann; Pascal FuaRepresenting motions as linear sums of principal components has become a widely accepted animation technique. While powerful, the simplest version of this approach is not particularly well suited to modeling the specific style of an individual whose motion had not yet been recorded when building the database: it would take an expert to adjust the PCA weights to obtain a motion style that is indistinguishable from his. Consequently, when realism is required, the current practice is to perform a full motion capture session each time a new person must be considered. In this paper, we extend the PCA approach so that this requirement can be drastically reduced: for whole classes of cyclic and noncyclic motions such as walking, running or jumping, it is enough to observe the newcomer moving only once at a particular speed or jumping a particular distance using either an optical motion capture system or a simple pair of synchronized video cameras. This one observation is used to compute a set of principal component weights that best approximates the motion and to extrapolate in real-time realistic animations of the same person walking or running at different speeds, and jumping a different distance.