35-Issue 2

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https://diglib.eg.org/handle/10.2312/15061

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Browsing 35-Issue 2 by Subject "Display Algorithms"

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    Regularizing Image Reconstruction for Gradient-Domain Rendering with Feature Patches
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Manzi, Marco; Vicini, Delio; Zwicker, Matthias; Joaquim Jorge and Ming Lin
    We present a novel algorithm to reconstruct high-quality images from sampled pixels and gradients in gradient-domain rendering. Our approach extends screened Poisson reconstruction by adding additional regularization constraints. Our key idea is to exploit local patches in feature images, which contain per-pixels normals, textures, position, etc., to formulate these constraints. We describe a GPU implementation of our approach that runs on the order of seconds on megapixel images. We demonstrate a significant improvement in image quality over screened Poisson reconstruction under the L1 norm. Because we adapt the regularization constraints to the noise level in the input, our algorithm is consistent and converges to the ground truth.
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    SAH Guided Spatial Split Partitioning for Fast BVH Construction
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Ganestam, Per; Doggett, Michael; Joaquim Jorge and Ming Lin
    We present a new SAH guided approach to subdividing triangles as the scene is coarsely partitioned into smaller sets of spatially coherent triangles. Our triangle split approach is integrated into the partitioning stage of a fast BVH construction algorithm, but may as well be used as a stand alone pre-split pass. Our algorithm significantly reduces the number of split triangles compared to previous methods, while at the same time improving ray tracing performance compared to competing fast BVH construction techniques. We compare performance on Intel's Embree ray tracer and show that BVH construction with our splitting algorithm is always faster than Embree's pre-split construction algorithm. We also show that our algorithm builds significantly improved quality trees that deliver higher ray tracing performance. Our algorithm is implemented into Embree's open source ray tracing framework, and the source code will be released late 2015.
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    Stylized Caustics: Progressive Rendering of Animated Caustics
    (The Eurographics Association and John Wiley & Sons Ltd., 2016) Günther, Tobias; Rohmer, Kai; Rössl, Christian; Grosch, Thorsten; Theisel, Holger; Joaquim Jorge and Ming Lin
    In recent years, much work was devoted to the design of light editing methods such as relighting and light path editing. So far, little work addressed the target-based manipulation and animation of caustics, for instance to a differently-shaped caustic, text or an image. The aim of this work is the animation of caustics by blending towards a given target irradiance distribution. This enables an artist to coherently change appearance and style of caustics, e.g., for marketing applications and visual effects. Generating a smooth animation is nontrivial, as photon density and caustic structure may change significantly. Our method is based on the efficient solution of a discrete assignment problem that incorporates constraints appropriate to make intermediate blends plausibly resemble caustics. The algorithm generates temporally coherent results that are rendered with stochastic progressive photon mapping. We demonstrate our system in a number of scenes and show blends as well as a key frame animation.