From Wikipedia

The Nude In Art

Episode One

Depictions of nudity refers to nudity in all the artistic disciplines including vernacular and historical depictions. Nudity in art has generally reflected — with some exceptions — social standards of aesthetics and morality of their time in painting, sculpture and more recently in photography.

Since prehistoric time, representations of the nude body has been a major theme in art.

Many cultures tolerate nudity in art more than actual nudity, with a different set of standards of what is acceptable. For example, even in a museum depicting nudity, nudity of a visitor is typically not accepted. On the other hand, child pornography laws often restrict depictions even more than the depicted acts (photographs of legal acts and even simple nudity may be illegal).

Sometimes live nudity is more acceptable if the model does not move; see Windmill Theatre. In other cultures, like Japan, where nudity carried no negative connotation, erotic shunga art tended to feature partially clothed participants.