I want to draw a figure in this post, but the result that I draw according to the following method is quite different from that in the post.
ParametricPlot3D[{r Cos[θ], r Sin[θ],
r^2*4 Mod[(1/r - θ/(2 π)),
1] (1 - Mod[(1/r - θ/(2 π)), 1])}, {θ, 0,
2 π}, {r, 0, 1}, PlotPoints -> 25, BoxRatios -> {1, 1, 1},
PlotRange -> {-1, 1}]
How can I draw a graph which is basically the same as the above one?