The velvet shader simulates the rim/fresnel lighting effect and softened specular highlights of cloth like velvet. It uses a micro-normal and micro-specular map, meaning that fiber-level detail should be left out of the normal map. The specular level (normal alpha) can be multiplied by a color to produce a colored specular highlight, which is very important for the rim lighting on certain materials.
diffuseLight Texture: This is your color texture, it should be mostly void of lighting detail. The ambient occlusion is held in the alpha.
normalSpec Texture: This is a normal map. It should not contain fibre-level detail. The specular level is held in the alpha channel, and it is multiplied by the specColor variable.
microTexture: The RGB holds the micro-normal map, it should be specific for the type of weave of the fabric. The alpha channel holds the micro-specular, which should be noise corresponding to the weave/MN, as it ‘breaks up’ the specular highlight by multiplying
micro-normal Textures: This is a generic looking “pore” texture.
ambCube Texture: This shader uses a diffusely convolved ambient cube map for ambient lighting.
specColor: This is the color of the specular highlights.
sssColor: This is the color of those areas where SSS contributes, especially on the ears, nose, and mouth area. The melanin color.