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Now showing 1 - 10 of 896
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    Simulation of Facial Muscle Actions Based on Rational Free Form Deformations
    (Blackwell Science Ltd and the Eurographics Association, 1992) Kalra, Prem; Mangili, Angelo; Thalmann, Nadia Magnenat; Thalmann, Daniel
    This paper describes interactive facilities for simulating abstract muscle actions using Rational Free Form Deformations (RFFD). The particular muscle action is simulated as the displacement of the control points of the control-unit for an RFFD defined on a region of interest. One or several simulated muscle actions constitute a Minimum Perceptible Action (MPA), which is defined as the atomic action unit, similar to Action Unit (AU) of the Facial Action Coding System (FACS), to build an expression.
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    Interactive Rendering of Volumetric Data Sets
    (The Eurographics Association, 1994) Juskiw, "Scott; Durdle, Nelson G.; W. Strasser
    The bela architecture for interactive rendering of regularly structured volumetric data sets is presented. The proposed architecture is scalable and uses custom processors to achieve high-speed shading, projection. and composition of voxel primitives. A general purpose image composition network supports the accumulation of both volumetric and geometric elements into the final rendered scene. Data access contentions between processors are eliminated via the use of an enhanced dual object space and image space partitioning scheme that does not require replication or redistribution of rendered data. The bela architecture is intended for rendering large data sets and meets the performance requirements of a full frame interactive image generation system.
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    Dynamic Load Balancing within a High PerformanceGraphics System
    (The Eurographics Association, 1991) Selzer, Harald; A. Kaufman
    Interactive 3D graphics applications require significant arithmetic processing to meet the ever-inreasing desire for higher image complexity and higher resolution in displayed images. This paper describes a graphics processor architecture with a high degree of parallelismconnected to a distributed frame buffer. The architecture can be configured with an arbitrary number of identical, high level programmable processors operating in parallel.Within the architecture an automatic load balancing mechanism is presented whichdistributes the processing load between geometry and rendering section. After the unique features of the architecture are described the load balancing mechanismis analyzed and the increase of performance is demonstrated."
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    intsys96
    (1996)
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    A Graph-Based Approach to Surface Reconstruction
    (Blackwell Science Ltd and the Eurographics Association, 1995) Mencl, Robert
    A new approach to the reconstruction of a surface from an unorganized set of points in space is presented. The point set may for example be obtained with a laser scanner or a manual digitizing tool, and is the only source of information about the shape of the acquired object. The basic idea is to calculate the Euclidean minimum spanning tree (EMST) of the given points. The EMST is then augmented to the so-called surface description graph (SDG). Finally the wire frame defined by the SDG are filled with triangles. The advantage of our approach is that also highly non-convex and even disconnected surfaces are reconstructed quite reliably. This is demonstrated for a variety of data sets.
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    Template-Based Volume Viewing
    (Blackwell Science Ltd and the Eurographics Association, 1992) Yagel, Roni; Kaufman, Arie
    We present an efficient three-phase algorithm for volume viewing that is based on exploiting coherency between rays in parallel projection. The algorithm starts by building a ray-template and determining a special plane for projection - the base-plane. Parallel rays are cast into the volume from within the projected region of the volume on the base-plane, by repeating the sequence of steps specified in the ray-template. We carefully choose the type of line to be employed and the way the template is being placed on the base-plane in order to assure uniform sampling of the volume by the discrete rays. We conclude by describing an optimized software implementation of our algorithm and reporting its performance.
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    Constructive Page Description Opening Up the Prepress World
    (Eurographics Association, 1991) Samara, Veronika; Wiedling, Hans-Peter
    Constructive Page Description (CPD) is an overall approach allowing different kinds of data to be exchanged between a variety of systems and manipulated in arbitrary system environments. Fully changeable pages, which keep information for modification as long as necessary, as well as fully assembled pages, ready for the printing process, can be constructed by the use of CPD. Moreover, descriptions of data as well as operations can be distributed, and so allow the use of networking facilities. CPD is thereby very flexible in handling, combining, and exchanging data and operations used in the construction of pages. In sum, CPD helps bridge the gap between the printing and the computer graphics world; it is an approach to lead prepress towards an open system architecture.
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    Extending Graphics Hardware For Occlusion Queries In OpenGL
    (The Eurographics Association, 1998) Bartz, Dirk; Meißner, Michael; Hüttner, Tobias; S. N. Spencer
    For interactive rendering of large polygonal objects, fast visibility queries are necessary to quickly decide whether polygonal objects are visible and need to be rendered. None of the numerous published algorithms provide visibility performance for interactive rendering of large models. In this paper, we propose an OpenGL extension for fast occlusion queries. Added after the depth test stage of the OpenGL rendering pipeline. our algorithm provides fast queries to establish the occlusion of polygonal objects. Furthermore, hardware aspects of this proposal are discussed and possible implementations on two different graphics architectures are presented.
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    Modelling and Programming Evolutions of Surfaces
    (Blackwell Science Ltd and the Eurographics Association, 1992) Chen, X.; Lienhardt, P.
    In recent years, a lot of work has been done on modelling natural phenomena and simulating the evolution of natural objects. For instance, procedural methods have been developed for simulating corpuscular phenomena and tree growth. In this paper we present a new procedural method for simulating evolutions of subdivisions of surfaces (i.e. partitions of surfaces into vertices, edges and faces). The representations of topology, embedding and photometry are clearly distinguished in the geometric model used for the representation of such subdivisions and thus, each of these features may be evolved independently (as in natural metamorphoses). Evolutions are achieved by applying topological and embedding operations on the geometric model. Control of these evolutions is based upon the behaviour concept. Behaviours (i.e. sets of operations) are associated with cells of the modelled subdivision. At each step, and for each cell, the corresponding behaviour is applied to the cell. The definition and computation of parameters have been studied, in order to control such evolutions. The method has been implemented and tested with many examples of surface evolutions (mainly evolutions of vegetal surfaces: leaves, flowers). Based on the method, a language has been defined for programming surface evolutions.
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    Network Services
    (Blackwell Publishers Ltd and the Eurographics Association, 1997)