#declare al= 12.0;
#declare cl= 4;
#declare ac= clock*al;
#declare cc= (ac/cl - int(ac/cl));
#macro tb(p)
(3*p * cos((p/24-cc)*10*pi))
#end
@rifleman: I tried that just to see how it would look, the combo of horizontal and vertical waves kinda counter-act eachother and not much seems to move.