Lamp shade from analytic expression

Lamp shade made from an analytic expression using this Mathematica code in case of #1:

ParametricPlot3D[
{If[z > 0, Cos[z], Exp[z/5]]*
(Cos[u] +
(1 + Tanh[z + \[Pi]/2])*(0.13 Sin[5 (u + z)] +
0.01 Sin[2.5 (u + z)]^2)*0.4 Cos[z]^2 + (1 + Tanh[z]) Cos[
15*z]*0.05),
If[z > 0, Cos[z], Exp[z/5]]*(Sin[u] +
(1 + Tanh[z + \[Pi]/2])*(0.13 Cos[5 (u + z)] +
0.01 Sin[2.5 (u + z)]^2)*
0.4 Cos[z]^2 + (1 + Tanh[z]) Sin[15*z]*0.