Cross Hole
By Roger Bagula
Graphics by
Paul Bourke
January 2004
x = cos(u) / (R tan(v))
y = cos(2 u) / R
z = sin(2 u) / R
Where
R = cos
^{2}
(u) cos
^{2}
(v) + sin
^{2}
(v)
and
0 <= u <= pi, 0 < v < pi