PG2016short

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https://diglib.eg.org/handle/10.2312/2630931

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Browsing PG2016short by Subject "Color"

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    Local Detail Enhancement for Volume Rendering under Global Illumination
    (The Eurographics Association, 2016) Zheng, Jinta; Zhang, Tianjin; Qin, Jing; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    We present a novel method for realistic perception enhanced volume rendering. Compared with traditional lighting systems, that either tend to eliminate important local shapes and details in volume data or cannot offer interactive global illumination, our method can enhance the edges and curvatures within a volume under global illumination through a user-friendly interface. We first propose an interactive volumetric lighting model to both simulate scattering and enhance the local detail information. In this model, users only need to determine a key light source. Next, we propose a new cue to intensify the shape perception by enhancing the local edges and details. The cue can be pre-computed and thus we can still keep the rendering process running real-time. Experiments on a variety of volume data demonstrate that the proposed method can generate more details, and hence more realistic rendering results.
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    Modified Filtered Importance Sampling for Virtual Spherical Gaussian Lights
    (The Eurographics Association, 2016) Tokuyoshi, Yusuke; Eitan Grinspun and Bernd Bickel and Yoshinori Dobashi
    This paper proposes a modification of the filtered importance sampling (FIS) method, and improves the quality of virtual spherical Gaussian light (VSGL) based real-time glossy indirect illumination using this modification. The original FIS method produces large overlaps of and gaps between filtering kernels for high-frequency probability density functions (PDFs). This is because the size of the filtering kernel is determined using the PDF at the sampled center of the kernel. To reduce those overlaps and gaps, this paper determines the kernel size using the integral of the PDF in the filtering kernel. Our key insight is that these integrals are approximately constant, if kernel centers are sampled using stratified sampling. Therefore, an appropriate kernel size can be obtained by solving this integral equation. Using the proposed kernel size for FIS-based VSGL generation, undesirable artifacts are significantly reduced with a negligibly small overhead.