Macro are useful too in order to apply translations or other modifiers to
different objects
e.g.
sphere{0 1 pigment{color rgb 0.2} translate<1,2,3>}
sphere {1 1 pigment{color rgb 0.4} translate<1,2,3>}
sphere {2 1 pigment{color rgb 0.6} translate<1,2,3>}
becomes
#macro M(c)pigment{color rgb c}translate<1,2,3>#end
sphere{0 1 M(.2)}
sphere{1 1 M(.4)}
sphere{2 1 M(.6)}
;-)
Paolo
