#macro C(c,d)crackle color_map{[0 rgb.3*c][.5 rgb 1-d]}#end plane{z,4 pigment{cells pigment_map{[0 C(z,x)][.3 C(y,x)][.8 C(x,y)][1 C(y,z)]}turbulence<15,50,20> scale 4 warp{repeat-x flip x}}finish{ambient 1}translate<9,7,0>}