I could never presume to tell the real experts about CalcNormals -
Fanatic, - maybe, ..... Expert? - never! ......
(I don't really understand what is going on! - but I DO like the effect!)
Do experiment with the n key though, - and check out these threads:-
https://www.feldoncentral.com/forums...ht=CalcNormals
https://www.feldoncentral.com/forums...s&pagenumber=5
....... and in particular, this one:-
https://www.feldoncentral.com/forums...s&pagenumber=3
Or just do a search on the forum for CalcNormals!
..................... May the CalcNormals be with you!