Twisted heart

By Roger Bagula
Graphics by Paul Bourke
January 2003


x = ( |v| - |u| - |tanh(m u)/m| + |tanh(m v)/m| ) sin(v) y = ( |v| + |u| - |tanh(m u)/m| - |tanh(m v)/m| ) cos(v)
z = m ( u2 + v2 ) / ( cosh(m u) cosh(m v) )
0 <= u <= pi, -pi <= v <= pi, and m = 1/sqrt(2)