It seems like alot of art features nudity and public bathhouses seem to be the norm for a long time, but seemingly out of no where (to me at least) nudity was viewed as something to hide and be humiliated by.
/u/AnnalsPornographie (formerly vertexoflife) has previously answered When/why did "private parts" become so private?
Related questions are also addressed in an AMA thread about the history of sexuality, featuring numerous flairs. See also AnnalsPornographie's solo outing about the history of porn and another one about porn and libertine literature co-hosted by /u/tfrauline.