在医院的时候闲着没事天天用笔记本看论文玩，翻到了一篇SIGGRAPH 2009的Poster名为《Reflection Model of Metallic Paints for Reflectance Acquisition》，由广岛城市大学（Hiroshima City University）的马场正志（Masashi Baba）和 浅田直树（Naoki Asada）所写。经过测试发现他们的模型要比mi_metallic_paint复杂一点点，而Flake层却又不同于mi_car_paint。这里的Flake层是用的高斯分布，也就是用样本去扰动第二高光。我直接在shader中采样高斯分布的CDF $\frac{1}{2}[1+erf(\frac{x-\mu}{\sgima\sqrt{2}})]$的反函数获得样本。
When I was in hospital, I spent my on bed time by reading papers, and I found a SIGGRAPH 2009 poster named "Reflection Model of Metallic Paints for Reflectance Acquisition" which is written by Masashi Baba and Naoki Asada from Hiroshima City University. Their model is fast, simple, similar to the mi_metallic_paint, but the Flake model is different than mi_car_paint.
Samples = 128, Sigma = 0.149, Mu = 0.001
Samples = 128, Sigma = 0.249, Mu = 0.001
Samples = 64, Sigma = 0.349, Mu = 0.001
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