The Subsurface scattering (SSS) channel simulates the effect of light scattering inside an object. It is useful for translucent materials like skin, wax, and ice.
- The Subsurface scattering texture is a grayscale image. It works as a mask to indicate where the effect is visible and how strong it is.
- The Subsurface profile is two colors that define the behavior and color of scattered light. It works similarly to the UE4 Subsurface Profile Shading. You may use up to 3 profiles per model.
- The Subsurface color is multiplied by the scattering color and can be used as a weight for the subsurface effect. 100% black means there is no subsurface effect, and 100% white means that all light that enters the material is scattered. Non-grayscale values give more control over color contribution.
- The Falloff color defines the material scattering color after light has entered the material.
The Translucency channel controls the backscattering of light behind an object. It is useful for materials like leaves and thin body parts like ears and noses.
- The Translucency texture is a grayscale texture that defines the depth or thickness of the material. Black values represent thin parts of the model, and white values represent thick parts of the model.
- The Color defines the color of the light passing through the object. It is usually the same as the subsurface profile color.
- The Thickness factor indicates how light is being dispersed.
Here is the same model with Subsurface scattering disabled: