Graphics Reference
In-Depth Information
7
Subsurface Scattering
in Cycles
In this chapter, we will cover the following recipes:
F
Using the Subsurface Scattering shader node
F
Simulating Subsurface Scattering in Cycles using the Translucent shader
F
Simulating Subsurface Scattering in Cycles using the Vertex Color tool
F
Simulating Subsurface Scattering in Cycles using the Ray Length output in the
Light Path node
F
Creating a fake Subsurface Scattering node group
Introduction
Subsurface Scattering is the effect of light not getting directly reflected by a surface but
penetrating it and bouncing internally before getting absorbed or leaving the surface at a
nearby point. In short, light is
scattered
.
The RGB channels of a surface color can have different scattering values, depending on
the material; for example, for human skin the red component is more scattered (as a rough
approximation, you could say that the values for the three channels are blue = 1, green = 2,
and red = 4).
In Cycles, a true Subsurface Scattering node has been introduced in Blender 2.67.
Since Version 2.72, it also works with the GPU (only in the Experimental feature set).
But sadly, it still has the common big Cycles problem—it takes a lot of samples to produce
a noise-free rendering. In short, it's slow.
