蜘蛛の巣 cobweb

同心円状の平明的な蜘蛛の巣はよくみかけますが、このような立体的な編みはあまり見かけません。
何か法則があるのか、思いつきか興味あるところです。

I often come across the two-dimensional cobweb knitted concentrically, but I don't come across such a three-dimensional compilation so much.
I am interested whether it has a rule or it is a simple idea.

1/125sec, F5.6, -0.5EV, ISO800, 60mm (aps-c)