体积散射¶
体积散射 节点允许光线在通过体积时产生散射现象。为场景添加雾效果是一个典型的用法。它也可以与 体积吸收 节点一起使用来制作烟雾效果。
输入¶
- 颜色
Scattering coefficients per color channel.
- 密度
散射效果的密度。
- 各向异性 Henyey-Greenstein Draine
Controls the relative amount of backward and forward scattering.
- 折射率 Fournier-Forand
Refractive index of the scattering particles relative to water. Common ocean waters range between 1.0 and 1.2, while turbid waters with higher density of particles have higher IORs.
- 反向散射 Fournier-Forand
Fraction of light that is scattered backwards. Most oceanic particles have backscatter values between 0.001 (e.g., very large phytoplankton) and 0.1 (e.g., very small mineral particles), pure water has a backscatter of 0.5. Values taken from Ocean Optics Web Book.
- Alpha Draine
Blending factor between Henyey-Greenstein (\(\alpha = 0\)) and Cornette & Shanks (\(\alpha = 1\)) phase functions.
- 直径 Mie
Diameter of the scattering particles in µm.
属性¶
- 相位
Volume scattering phase function.
- Henyey-Greenstein:
Simple and widely used phase function, useful for approximating scattering in biological tissues.
- Fournier-Forand:
Cycles Only Suitable for modeling the scattering of light in underwater environments.
- Draine:
Cycles Only Suitable for modeling the scattering of interstellar dust.
- Rayleigh:
Cycles Only Describes the scattering by particles with a size smaller than the wavelength of light, such as the scattering of sunlight in earth's atmosphere.
- Mie:
Cycles Only Describes the scattering by particles with a size larger than the wavelength of light, such as cloud and fog.
Tip
These phase functions can be combined using a 混合着色器.
Volume scattering phase as a function of angles between the incoming and the outgoing direction, in logarithmic scale. Light comes from the left side.¶
输出¶
示例¶
体积散射着色器节点效果。¶