0138 Astroid Torus (R=8, r=2, θ=pi/4) 7/8 part

KOSEKOMA 0138 - Parametric surface F(u,v) - Astroidal Torus 7/8 part
A parametric surface is a surface F(u,v) in the Euclidean space R3 which is defined by a parametric equation with two parameters u, v.

Parametric surface F(u,v) Astroidal Torus.
A surface of the rotation of an astroid is formed by an asteroid rotating about any of two its axes Ox or Oz
x = (R + r cos(v)^3) cos(u)
y = (R + r cos(v)^3) sin(u)
z = r sin(v)^3
u = 0..2π; v = 0..(7/4)π