Subsurface Scattering and Fine Art Sculpture

Industrial designer, Ernest McCrank attended my Studio Show last December and after admiring one of my sculptures, remarked to me that he was fascinated by the subsurface scattering he observed. I had never heard of this scientific term and asked him to explain.

Subsurface scattering is a mechanism of light transport in which light penetrates the surface of a translucent object, is scattered by interacting with the material, and exits the surface at a different point. The light will generally penetrate the surface and be reflected a number of times at irregular angles inside the material, before passing out of the material at an angle other than the angle it would have if it had been reflected directly off the surface.

This is a bit more detailed explanation of what I have always referred to as translucency. Many stones that I carve are translucent, such as alabaster, onyx, jade, and marble. Light penetrates into these stones, and in some instances passes right through them. An example is the attached photo of a female torso I carved from honey onyx.

This is a scientific explanation for the beautiful aesthetic occurrence of light falling on stone and in some instances leaving the viewer mesmerized.

This is why when a portrait is executed in certain stones, no matter how exact the details are, the stone will never look exactly as the sitter. Light reflects off of the surface of stone differently than skin.

Subsurface scattering is important to 3D designers to assist them in creating a more lifelike computer generated image.