       SippShaderMarble ambient specular c3 scale basecolor stripcolor [opacity]
              This shader creates a simulated marble texture on a
              surface.  It uses two colors, one as the base mate-
              rial  and  one  as  the  interspersed material. The
              interspersed material is put into the base material
              in strips that are distorted using noise() and tur-
              bulence().

              ambient is a value between 0.0 and 1.0 which deter-
              mines  how much of the base color of a surface that
              is visible when it is not illuminated by any  light
              source.

              specular  is  a  value between 0.0 and 1.0 which is
              the fraction of color specularly reflected.

              c3 is the shininess of the surface where 0.0 is the
              most dull and 1.0 is the most shiny.

              scale  describes  how  much the texture coordinates
              should be scaled before applying  the  marble  tex-
              ture.  The larger the scaling, the smaller the area
              of the marble texture associated with a given  area
              of  the  surface.  A large number results in a very
              fine pattern, a small number yields a  coarse  pat-
              tern.

              basecolor  is  a list containing the red, green and
              blue values for the base material.   Each  being  a
              number between 0.0 and 1.0.

              stripcolor  is a list containing the red, green and
              blue values for the interspersed material.

              opacity describes the opacity  of  a  surface.  0.0
              means   totally   transparent,  1.0  means  totally
              opaque.  May be a list of red, green and blue opac-
              ity  values  or  a  single value to be used for all
              color channels.  Optional, default is 1.0.
