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Now showing 1 - 10 of 46
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    A Parallel Approach to Compression and Decompression of Triangle Meshes using the GPU
    (The Eurographics Association and John Wiley & Sons Ltd., 2017) Jakob, Johannes; Buchenau, Christoph; Guthe, Michael; Bærentzen, Jakob Andreas and Hildebrandt, Klaus
    Most state-of-the-art compression algorithms use complex connectivity traversal and prediction schemes, which are not efficient enough for online compression of large meshes. In this paper we propose a scalable massively parallel approach for compression and decompression of large triangle meshes using the GPU. Our method traverses the input mesh in a parallel breadth-first manner and encodes the connectivity data similarly to the well known cut-border machine. Geometry data is compressed using a local prediction strategy. In contrast to the original cut-border machine, we can additionally handle triangle meshes with inconsistently oriented faces. Our approach is more than one order of magnitude faster than currently used methods and achieves competitive compression rates.
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    Iso Photographic Rendering
    (The Eurographics Association, 2018) Porral, Philippe; Lucas, Laurent; Muller, Thomas; Randrianandrasana, Joël; Reinhard Klein and Holly Rushmeier
    In the field of computer graphics, the simulation of the visual appearance of materials requires an accurate computation of the light transport equation. Consequently, material models need to take into account various factors which may influence the spectral radiance perceived by the human eye. Though numerous relevant studies on the reflectance properties of materials have been conducted to date, environment maps used to simulate visual behaviors remain chiefly trichromatic. Whereas questions regarding the accurate characterization of natural lighting have been raised for some time, there are still no real sky environment maps that include both spectral radiance and polarization data. Under these conditions the simulations carried out are approximate and therefore insufficient for the industrial world where investment-sensitive decisions are often made based on these very calculations.
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    Real-Time Bump Map Synthesis
    (The Eurographics Association, 2001) Kautz, Jan; Heidrich, Wolfgang; Seidel, Hans-Peter; Kurt Akeley and Ulrich Neumann
    In this paper we present a method that automatically synthesizes bump maps at arbitrary levels of detail in real-time. The only input data we require is a normal density function; the bump map is generated according to that function. It is also used to shade the generated bump map. The technique allows to infinitely zoom into the surface, because more (consistent) detail can be created on the fly. The shading of such a surface is consistent when displayed at different distances to the viewer (assuming that the surface structure is self-similar). The bump map generation and the shading algorithm can also be used separately.
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    Ray-Traced Collision Detection: Interpenetration Control and Multi-GPU Performance
    (The Eurographics Association, 2013) Lehericey, Francois; Gouranton, Valérie; Arnaldi, Bruno; Betty Mohler and Bruno Raffin and Hideo Saito and Oliver Staadt
    We proposed in [LGA13] an iterative ray-traced collision detection algorithm (IRTCD) that exploits spatial and temporal coherency and proved to be computationally efficient but at the price of some geometrical approximations that allow more interpenetration than needed. In this paper, we present two methods to efficiently control and reduce the interpenetration without noticeable computation overhead. The first method predicts the next potentially colliding vertices. These predictions are used to make our IRTCD algorithm more robust to the above-mentioned approximations, therefore reducing the errors up to 91%. We also present a ray re-projection algorithm that improves the physical response of ray-traced collision detection algorithm. This algorithm also reduces, up to 52%, the interpenetration between objects in a virtual environment. Our last contribution shows that our algorithm, when implemented on multi-GPUs architectures, is far faster.
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    VoxelCache: A Cache-Based Memory Architecture for Volume Graphics
    (The Eurographics Association, 2003) Kanus, U.; Wetekam, G.; Hirche, J.; M. Doggett and W. Heidrich and W. Mark and A. Schilling
    This paper presents a cache-based memory architecture for volume graphics. We describe the memory organization and cache logic to implement a voxel cache based on 43 voxel blocks. We show an efficient prefetching scheme that increases the cache hit ratio to more than 98% in most cases. The performance of the memory system with different types of external memory is demonstrated by a cycle accurate C++ simulation. The VoxelCache memory architecture is designed to be easily adapted to different memory technologies, because all volume graphics specific parts of the memory system are encapsulated inside the on-chip cache. The design is targeted at implementation on off-the-shelf reconfigurable hardware.
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    Reduced Precision for Hardware Ray Tracing in GPUs
    (The Eurographics Association, 2014) Keely, Sean; Ingo Wald and Jonathan Ragan-Kelley
    We propose a high performance, GPU integrated, hardware ray tracing system. We present and make use of a new analysis of ray traversal in axis aligned bounding volume hierarchies. This analysis enables compact traversal hardware through the use of reduced precision arithmetic. We also propose a new cache based technique for scheduling ray traversal. With the addition of our compact fixed function traversal unit and cache mechanism, we show that current GPU architectures are well suited for hardware accelerated ray tracing, requiring only small modifications to provide high performance. By making use of existing GPU resources we are able to keep all rays and scheduling traffic on chip and out of caches. We used simulations to estimate the performance of our architecture. Our system achieves an average ray rate of 3.4 billion rays per second while path tracing our test scenes.
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    Path Tracing on Massively Parallel Neuromorphic Hardware
    (The Eurographics Association, 2012) Richmond, Paul; Allerton, David J.; Hamish Carr and Silvester Czanner
    Ray tracing on parallel hardware has recently benefit from significant advances in the graphics hardware and associated software tools. Despite this, the SIMD nature of graphics card architectures is only able to perform well on groups of coherent rays which exhibit little in the way of divergence. This paper presents SpiNNaker, a massively parallel system based on low power ARM cores, as an architecture suitable for ray tracing applications. The asynchronous design allows us to demonstrate a linear performance increase with respect to the number of cores. The performance perWatt ratio achieved within the fixed point path tracing example presented is far greater than that of a multi-core CPU and similar to that of a GPU under optimal conditions.
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    Packet-Oriented Streamline Tracing on Modern SIMD Architectures
    (The Eurographics Association, 2015) Hentschel, Bernd; Göbbert, Jens Henrik; Klemm, Michael; Springer, Paul; Schnorr, Andrea; Kuhlen, Torsten W.; C. Dachsbacher and P. Navrátil
    The advection of integral lines is an important computational kernel in vector field visualization. We investigate how this kernel can profit from vector (SIMD) extensions in modern CPUs. As a baseline, we formulate a streamline tracing algorithm that facilitates auto-vectorization by an optimizing compiler. We analyze this algorithm and propose two different optimizations. Our results show that particle tracing does not per se benefit from SIMD computation. Based on a careful analysis of the auto-vectorized code, we propose an optimized data access routine and a re-packing scheme which increases average SIMD efficiency. We evaluate our approach on three different, turbulent flow fields. Our optimized approaches increase integration performance up to 5:6 over our baseline measurement. We conclude with a discussion of current limitations and aspects for future work.
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    A Flexible Simulation Framework for Graphics Architectures
    (The Eurographics Association, 2004) Sheaffer, J. W.; Luebke, D.; Skadron, K.; Tomas Akenine-Moeller and Michael McCool
    In this paper we describe a multipurpose tool for analysis of the performance characteristics of computer graphics hardware and software. We are developing Qsilver, a highly configurable micro-architectural simulator of the GPU that uses the Chromium system's ability to intercept and redirect an OpenGL stream. The simulator produces an annotated trace of graphics commands using Chromium, then runs the trace through a cycle-timer model to evaluate time-dependent behaviors of the various functional units. We demonstrate the use of Qsilver on a simple hypothetical architecture to analyze performance bottlenecks, to explore new GPU microarchitectures, and to model power and leakage properties. One innovation we explore is the use of dynamic voltage scaling across multiple clock domains to achieve significant energy savings at almost negligible performance cost. Finally, we discuss how other architectural features and experiments might be incorporated into the Qsilver framework.
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    Interactive Rendering of Atmospheric Scattering Effects Using Graphics Hardware
    (The Eurographics Association, 2002) Dobashi, Yoshinori; Yamamoto, Tsuyoshi; Nishita, Tomoyuki; Thomas Ertl and Wolfgang Heidrich and Michael Doggett
    To create realistic images using computer graphics, an important element to consider is atmospheric scattering, that is, the phenomenon by which light is scattered by small particles in the air. This effect is the cause of the light beams produced by spotlights, shafts of light, foggy scenes, the bluish appearance of the earth s atmosphere, and so on. This paper proposes a fast method for rendering the atmospheric scattering effects based on actual physical phenomena. In the proposed method, look-up tables are prepared to store the intensities of the scattered light, and these are then used as textures. Realistic images are then created at interactive rates by making use of graphics hardware.