background{rgb<.2,.4,.8>}camera{location-5*z rotate x*45}light_source{-5*z,.8rotate<30,120>}
#declare s=function(x,y){3/(x*x+y*y+.5)}
#declare g=function{pattern{granite scale 6-y*2}}
#declare f=function(x,y,z,a,b){pow(g(x*a+z*b,y+clock*3,x*b-z*a),.6)}
#declare h=function(x,y,z,a){f(x,y,z,sin(a),cos(a))}
lathe{bezier_spline 4<0,-2>0 1<4,2>
texture{pigment{rgb<.5,.8,.7>}finish{diffuse.3phong 1specular.5reflection{.2,.75fresnel}}
normal{function{h(x,y,z,s(x,z))}-1.5}}no_shadow}