Subsurface scattering

Bakery has experimental support for subsurface scattering based on Beer-Lambert law. This effect is useful to simulate light passing through diffuse translucent media, such as skin, wax, curtains, etc.

Lightmap group with subsurface scattering enabled

Subsurface scattering used on curtains

Subsurface scattering visible on character's ear

Subsurface settings are accessible per-group by enabling a "Subsurface scattering" checkbox. All objects belonging to the group will be affected.

Scattering requires objects to have volume, i.e. a simple flat polygon won't work. Bakery will trace light paths from one side of the volume to another. This means even in case of curtains geometry must have some thickness.

Options:

• Samples: affects quality. Typical values are 16-32, similar to GI samples.
• Density: describes density of the medium inside the volume. Affects light attenuation, higher values will pass less light. While not measured and purely eyeballed, these are some values to get you started:
  • Skin (head mesh): 5
  • Curtain: 1
• Color: color attenuation inside the volume.