I discovered this excellent answer which contains a so beautiful plot.
I just copied the whole code and tried to reproduce the result but the contour plot used as texture looks like flipped, that is, when I see the plot from above the result is
and if I see it from below the result is
How to fix this? I mean, how to put the white color visible from the top?
I'm using Mathematica 9.
FaceForm[Opacity[1], Opacity[.8]]
beforeTexture[..]
in the definition ofgr
. $\endgroup$