Subsurface Scattering

What is subsurface scattering and how does it contribute to realism?
GLOSSARY
Subsurface Scattering (SSS) is a mechanism in computer graphics that simulates the effect of light penetrating semi-transparent materials, such as skin, wax, or leaves. This technique accounts for light that enters an object and scatters internally before exiting at a different point, contributing significantly to the realism of digital imagery by mimicking the natural play of light on objects.
In character animation, particularly for human characters, subsurface scattering is important for achieving lifelike skin. It ensures that light interacts with the skin's layers in a realistic manner, softening shadows and allowing highlights to reflect the subtle translucency of flesh.
Technical definition
Implementing SSS involves complex calculations within rendering software to simulate the behavior of light inside translucent materials. Parameters such as scattering radius, color, and index of refraction are adjusted to control how light diffuses beneath the surface, affecting the material's appearance. Effective use of SSS can dramatically enhance the authenticity and visual appeal of a wide range of materials in 3D models and environments.