There are Hollywood even big budget (big name mainstream stars) ero-films for reference. Eyes wide shut, Showgirls etc. One of the best ever was Caligula, plenty of sex (but no genitals) and it's actually quite historical.
http://www.esquire.com/lifestyle/sex/news/g2818/best-movie-sex-scenes/
Plenty of nudity, sex-themed, but also "good" enough to appear at film fests, even get some Oscar, Golden Globe etc nominations.
Softcore is as
@Supmop said, porn (only purpose is fapping aid) but when the laws get in the way.