This surface is describable parametrically as:

X(s,t) = s
Y(s,t) = t
Z(s,t) = 5*cos((s^2 + t^2) /200) - 3*cos(s*t /200) + cos(s) - cos(t)
domain: s [-50, 50]; t [-50, 50];

the object.

rotated 90 deg counter clockwise about the verticle axis.

the under side.

rendered as points and solid from the same perspective.