Surface effect treatment

Grasshopper
1

I like this effect, but with my current ability, I don’t know how to do it

%E5%BE%AE%E4%BF%A1%E5%9B%BE%E7%89%87_20190812174336
%E5%BE%AE%E4%BF%A1%E5%9B%BE%E7%89%87_201908121743361544×647 697 KB
%E5%BE%AE%E4%BF%A1%E5%9B%BE%E7%89%87_20190812174344
%E5%BE%AE%E4%BF%A1%E5%9B%BE%E7%89%87_201908121743441479×675 605 KB