EG2015

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https://diglib.eg.org/handle/10.2312/12086

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Browsing EG2015 by Subject "and systems"

Now showing 1 - 5 of 5
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    Designing Camera Networks by Convex Quadratic Programming
    (The Eurographics Association and John Wiley & Sons Ltd., 2015) Ghanem, Bernard; Cao, Yuanhao; Wonka, Peter; Olga Sorkine-Hornung and Michael Wimmer
    In this paper, we study the problem of automatic camera placement for computer graphics and computer vision applications. We extend the problem formulations of previous work by proposing a novel way to incorporate visibility constraints and camera-to-camera relationships. For example, the placement solution can be encouraged to have cameras that image the same important locations from different viewing directions, which can enable reconstruction and surveillance tasks to perform better. We show that the general camera placement problem can be formulated mathematically as a convex binary quadratic program (BQP) under linear constraints. Moreover, we propose an optimization strategy with a favorable trade-off between speed and solution quality. Our solution is almost as fast as a greedy treatment of the problem, but the quality is significantly higher, so much so that it is comparable to exact solutions that take orders of magnitude more computation time. Because it is computationally attractive, our method also allows users to explore the space of solutions for variations in input parameters. To evaluate its effectiveness, we show a range of 3D results on real-world floorplans (garage, hotel, mall, and airport).
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    Fast Edge-based Geodesic Poisson Disk Remeshing
    (The Eurographics Association, 2015) Uhlmann, Tom; Váša, Libor; Brunnett, Guido; B. Bickel and T. Ritschel
    Triangular meshes of high complexity are common when created by a 3D scanner device and must be reduced for further processing. The geodesic Poisson disk remeshing [FZ08] is a method that generates a simplified mesh with highly regular triangles at the cost of exorbitant computation time. In this paper we will outline a new approach to this technique that makes it applicable for highly complex models. Our approach operates directly on the surface of the mesh, therefore works for meshes of arbitrary topology. Meshes consisting of millions of triangles can be reduced to an arbitrary complexity in just a few minutes while the original approach processes meshes with thousands of triangles in the same time. Our easy to implement remeshing technique also provides several options to preserve features.
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    Fractured Object Reassembly via Robust Surface Registration
    (The Eurographics Association, 2015) Mavridis, Pavlos; Andreadis, Anthousis; Papaioannou, Georgios; B. Bickel and T. Ritschel
    The reassembly of fractured 3D objects from their parts is an important problem in cultural heritage and other domains.We approach reassembly from a geometric matching perspective and propose a pipeline for the automatic solution of the problem, where an efficient and generic three-level coarse-to-fine search strategy is used for the underlying global optimization. Key to the efficiency of our approach is the use of a discretized approximation of the surfaces' distance field, which significantly reduces the cost of distance queries and allows our method to systematically search the global parameter space with minimal cost. The resulting reassembly pipeline provides highly reliable alignment, as demonstrated through the reassembly of fractured objects from their fragments and the reconstruction of 3D objects from partial scans, showcasing the wide applicability of our methodology.
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    Interactive Disassembly Planning for Complex Objects
    (The Eurographics Association and John Wiley & Sons Ltd., 2015) Kerbl, Bernhard; Kalkofen, Denis; Steinberger, Markus; Schmalstieg, Dieter; Olga Sorkine-Hornung and Michael Wimmer
    We present an approach for the automatic generation, interactive exploration and real-time modification of disassembly procedures for complex, multipartite CAD data sets. In order to lift the performance barriers prohibiting interactive disassembly planning, we run a detailed analysis on the input model to identify recurring part constellations and efficiently determine blocked part motions in parallel on the GPU. Building on the extracted information, we present an interface for computing and editing extensive disassembly sequences in real-time while considering user-defined constraints and avoiding unstable configurations. To evaluate the performance of our C++/CUDA implementation, we use a variety of openly available CAD data sets, ranging from simple to highly complex. In contrast to previous approaches, our work enables interactive disassembly planning for objects which consist of several thousand parts and require cascaded translations during part removal.
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    Template Assembly for Detailed Urban Reconstruction
    (The Eurographics Association and John Wiley & Sons Ltd., 2015) Nan, Liangliang; Jiang, Caigui; Ghanem, Bernard; Wonka, Peter; Olga Sorkine-Hornung and Michael Wimmer
    We propose a new framework to reconstruct building details by automatically assembling 3D templates on coarse textured building models. In a preprocessing step, we generate an initial coarse model to approximate a point cloud computed using Structure from Motion and Multi View Stereo, and we model a set of 3D templates of facade details. Next, we optimize the initial coarse model to enforce consistency between geometry and appearance (texture images). Then, building details are reconstructed by assembling templates on the textured faces of the coarse model. The 3D templates are automatically chosen and located by our optimization-based template assembly algorithm that balances image matching and structural regularity. In the results, we demonstrate how our framework can enrich the details of coarse models using various data sets.