Rendering glints on high-resolution normal-mapped specular surfaces
Rendering glints on high-resolution normal-mapped specular surfaces
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DOI：
10.1145/2601097.2601155
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发表时间：
2014-07
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影响因子：
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通讯作者：
Ling-Qi Yan;Miloš Hašan;Wenzel Jakob;Jason Lawrence;Steve Marschner;R. Ramamoorthi
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文献类型：
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作者：
Ling-Qi Yan;Miloš Hašan;Wenzel Jakob;Jason Lawrence;Steve Marschner;R. Ramamoorthi
在锐点照明下的复杂镜面显示出迷人的闪耀外观，但渲染它是一个悬而未决的问题。为此，使用蒙特卡罗像素采样是不切实际的：能量集中在极小的高光中，这些高光只占像素的一小部分。相反，我们使用一种完全不同的确定性方法来计算准确的解。我们的方法考虑了通过单个像素看到的曲面片上的法线的真实分布，这可能是非常复杂的。我们展示了如何有效地评估这种分布，假设像素足迹和高斯固有粗糙度为高斯值。我们还利用位置法线空间的分层剪枝来快速找到可能对给定正态分布评估有贡献的纹理元素。我们的结果显示了复杂的、随时间变化的闪烁，这些闪烁来自凹凸不平的塑料、刷子和划痕的金属、金属油漆和海浪等材料。
Complex specular surfaces under sharp point lighting show a fascinating glinty appearance, but rendering it is an unsolved problem. Using Monte Carlo pixel sampling for this purpose is impractical: the energy is concentrated in tiny highlights that take up a minuscule fraction of the pixel. We instead compute an accurate solution using a completely different deterministic approach. Our method considers the true distribution of normals on a surface patch seen through a single pixel, which can be highly complex. We show how to evaluate this distribution efficiently, assuming a Gaussian pixel footprint and Gaussian intrinsic roughness. We also take advantage of hierarchical pruning of position-normal space to rapidly find texels that might contribute to a given normal distribution evaluation. Our results show complex, temporally varying glints from materials such as bumpy plastics, brushed and scratched metals, metallic paint and ocean waves.