%var x y z
g = golden_ratio; r = 10
p = 2 - (cos(x + g*y) + cos(x - g*y) + cos(y + g*z) +
cos(y - g*z) + cos(z - g*x) + cos(z + g*x))
show(implicit_plot3d(p, (x, -r, r), (y, -r, r), (z, -r, r),
plot_points=30, color='orange', mesh=1, opacity=.7), spin=1)