VMV17

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https://diglib.eg.org/handle/10.2312/2631688

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Browsing VMV17 by Subject "Computing methodologies"

Now showing 1 - 5 of 5
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    Appearance Bending: A Perceptual Editing Paradigm for Data-Driven Material Models
    (The Eurographics Association, 2017) Mylo, Marlon; Giesel, Martin; Zaidi, Qasim; Hullin, Matthias; Klein, Reinhard; Matthias Hullin and Reinhard Klein and Thomas Schultz and Angela Yao
    Data-driven representations of material appearance play an important role in a wide range of applications. Unlike with analytical models, however, the intuitive and efficient editing of tabulated reflectance data is still an open problem. In this work, we introduce appearance bending, a set of image-based manipulation operators, such as thicken, inflate, and roughen, that implement recent insights from perceptual studies. In particular, we exploit a link between certain perceived visual properties of a material, and specific bands in its spectrum of spatial frequencies or octaves of a wavelet decomposition. The result is an editing interface that produces plausible results at interactive rates, even for drastic manipulations. We present the effectiveness of our method on a database of bidirectional texture functions (BTFs) for a variety of material samples.
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    Interactive Visualization of Gaps and Overlaps for Large and Dynamic Sphere Packings
    (The Eurographics Association, 2017) Gu, Feng; Yang, Zhixing; Kolonko, Michael; Grosch, Thorsten; Matthias Hullin and Reinhard Klein and Thomas Schultz and Angela Yao
    To gain insight into many properties of granular matter, a particle packing can be simulated. For a dry particle mixture, collective rearrangement is often used as an iterative process to place the particles. In this paper, we present a new visualization technique to judge the quality of a collective rearrangement simulation of many spheres with a given particle size distribution. In addition to a visualization of the spheres themselves, we directly visualize the gaps and overlaps of the spheres in each iteration. This allows to see the regions where the simulation is not yet converged as well as the free spaces where spheres can still move into. Our method supports millions of spheres at interactive to real-time frame rates, allowing the user to inspect the sphere packing during the simulation.We demonstrate that this type of visualization better shows the structure of the current sphere arrangement than standard techniques like 2D clipping planes and therefore serves as a visual feedback to support the development of the packing simulation.
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    LiteMaker: Interactive Luminaire Development using Progressive Photon Tracing and Multi-Resolution Upsampling
    (The Eurographics Association, 2017) Krösl, Katharina; Luksch, Christian; Schwärzler, Michael; Wimmer, Michael; Matthias Hullin and Reinhard Klein and Thomas Schultz and Angela Yao
    Industrial applications like luminaire development (the creation of a luminaire in terms of geometry and material) or lighting design (the efficient and aesthetic placement of luminaires in a virtual scene) rely heavily on high realism and physically correct simulations. Using typical approaches like CAD modeling and offline rendering, this requirement induces long processing times and therefore inflexible workflows. In this paper, we combine a GPU-based progressive photon-tracing algorithm to accurately simulate the light distribution of a luminaire with a novel multi-resolution image-filtering approach that produces visually meaningful intermediate results of the simulation process. By using this method in a 3D modeling environment, luminaire development is turned into an interactive process, allowing for real-time modifications and immediate feedback on the light distribution. Since the simulation results converge to a physically plausible solution that can be imported as a representation of a luminaire into a light-planning software, our work contributes to combining the two former decoupled workflows of luminaire development and lighting design, reducing the overall production time and cost for luminaire manufacturers.
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    Pixel Cache Light Tracing
    (The Eurographics Association, 2017) Jendersie, Johannes; Rohmer, Kai; Brüll, Felix; Grosch, Thorsten; Matthias Hullin and Reinhard Klein and Thomas Schultz and Angela Yao
    In this paper, we introduce Pixel Cache Light Tracing, which is a new low-noise combination of eye-path and light-path tracing. In the first pass, eye-path vertices are distributed from the observer and stored in a hit point map analogous to progressive photon mapping. In the second pass, photons are traced from the light source and projected to the image as well as gathered by the hit point map. We combine the paths from both sampling strategies in a deterministic way without multiple importance sampling, such that the final result is consistent and free from firefly artifacts. In many practical cases, this combination leads to sharper caustics and reduced noise when compared to alternative techniques at equal time. Further, the simplicity of the path combination strategy is predestined for GPU-based implementations and requires less memory than a comparable photon mapping implementation. In addition, we provide a fast, parallel and lean hash map implementation for both photon and hit point queries.
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    User-study Based Optimization of Fast and Accurate Mahalanobis Brushing in Scatterplots
    (The Eurographics Association, 2017) Fan, Chaoran; Hauser, Helwig; Matthias Hullin and Reinhard Klein and Thomas Schultz and Angela Yao
    Brushing is at the heart of most modern visual analytics solutions with coordinated, multiple views and effective brushing is crucial for swift and efficient processes in data exploration and analysis. Given a certain data subset that the user wishes to brush in a data visualization, traditional brushes are usually either accurate (like the lasso) or fast (e.g., a simple geometry like a rectangle or circle). In this paper, we now present a new, fast and accurate brushing technique for scatterplots, based on the Mahalanobis brush, which we have extended and then optimized using data from a user study. We explain the principal, sketchbased model of our new brushing technique (based on a simple click-and-drag interaction), the details of the user study and the related parameter optimization, as well as a quantitative evaluation, considering efficiency, accuracy, and also a comparison with the original Mahalanobis brush.