Boy Surface, #2

Written by Paul Bourke
See also Boy surface #1
January 2004

Projective plane without singularities.

x = cos(t) sin(s)
y = sin(t) sin(s)
z = cos(s)

x^| = A ((2 x² - y² - z²) + 2 y z (y² - z²) + z x (x² - z²) + x y (y² - x²))
y^| = B ((y² - z²) + z x (z² - x²) + x y (y² - x²))
z^| = C (x + y + z) ((x + y + z)³ + 4 (y - x) (z - y) (x - z))

where A = 1/2, B = sqrt(3)/2, and C = 1/8
and 0 <= s,t <= pi