9.5.2

882 • CHAPTER 18
THE SHADERS • 883
 Not only does the shading creep around corners, it seems to be generated by the inside of the
object. Only where the object is a lot thicker than the sample area radius does the shading really get
darker. The reason being, when the object is thinner than the radius there will be samples taken from
the other side of the object, where the object doesn‘t cast a shadow. This effect, when applied well,
comes close to SubSurface Scattering, though it is actually entirely different. Nevertheless, it makes for
a great wax shader, and when used moderately, can be used to make surfaces like human skin much
more realistic, thanks to the light creeping around corners and the softening of shading.
Shader Properties
Samples
Use this setting to dene the amount of samples ChanLum should take in a given area, be it along
a normal or within a spherical sample area. The rst sample is always taken from the offset sample
point. If you set ChanLum to take just one sample, the settings that will no longer apply (like sample
radius and type) will be grayed out.