Wasn't it Ken who wrote:
>
>
>Nekar Xenos wrote:
>
>> Ok, so what's the isosurface formula for each of these?  =)
>
>Parametric:
>
>   This short note describes the parametric equations which give
>   rise to an approximate model of a drop of water, for example, a
>   tear drop.
>  
>   The equations as functions of longitute phi and lattitude theta are:
>  
>  x = 0.5 *(1-cos(8)) sin(8) cos(circle with verticle line through it)
>  y = 0.5 *(1-cos(8)) sin(8) sin(circle with verticle line through it)
>  z = cos(8)
>  
>    where 0 <= circ w/line tru/it  <= 2pi
>    and 0   <= 8 <= pi

For those of you who prefer stuff in POV language:-

#version 3.5;

camera { location  <0, 0, -2.4> look_at 0}

light_source {<100,100,-100> colour rgb 1}                              

#declare Fx = function(u,v) {0.5 *(1-cos(u)) *sin(u) *cos(v)}
#declare Fz = function(u,v) {0.5 *(1-cos(u)) *sin(u) *sin(v)}
#declare Fy = function(u,v) {cos(u)}
                        
#declare Umin = 0;
#declare Umax = pi;
#declare Vmin = 0;                       
#declare Vmax = 2*pi;

#declare Iter_U = 50;
#declare Iter_V = 50;

#include "param.inc"
Parametric()

object {Surface
  pigment {rgb 0.9}
}

I've used Ingo's "param.inc" because when I tried it as a real
parametric isosurface the "pixels per hour" figure looked like it was
heading for zero. I've switched the z and y values so that the pointy
bit is at the top.


-- 
Mike Williams
Gentleman of Leisure

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