/* Minimal camera */
camera {
   location <1,0,7>
   look_at 0
}

/* Three coloured lights */
light_source { <-9,0,9> rgb <1,0,0> }
light_source {9*z rgb <0,1,0> }
light_source { <9,0,9> rgb <0,0,1> }

/* Chladni plate equation */
isosurface { 
   function { cos(2*x) + cos(2*y) + cos(2*z) }
   contained_by { sphere {0,5} }
   open 
   /* max_gradient 5 */
   pigment {rgb 1} 
   finish {phong 1}
}