ALTHOUGH his DIY flicks influenced Andy Warhol, Federico Fellini, John Waters and countless music-video directors, among others, the legendary underground filmmaker Jack Smith (1932-1989) is barely remembered today.

“Jack Smith and the Destruction of Atlantis,” a solid new documentary by Mary Jordan, reveals that’s largely Smith’s own doing. He was “defiantly uncommercial,” the admiring Waters says – and delighted in attacking museums, sometimes collaborator Warhol (who called him “the only person I would ever try to copy”) and even the godfather of underground films, Jonas Mekas.

It also doesn’t help Smith’s rep that he never finished a movie after his groundbreaking and hugely influential “Flaming Creatures” (1963) was banned in 22 states because of its nudity and polymorphous sexuality. From that point, Smith presented his flicks as works-in-progress that he personally edited on the spot for every showing, which he sometimes began at 3 a.m. to weed out dilettantes.

In his later years, Smith, who was also a gifted photographer, largely abandoned films in favor of performance art – and his art apparently included deliberately contracting the AIDS that ended his life.

This invaluable record contains a treasure trove of clips from Smith’s hard-to-see and still striking films, plus comments that were culled from hours of interviews with this flamboyant pioneer – and interviews with survivors of an era when downtown wasn’t overrun by investment bankers.

JACK SMITH AND THE DESTRUCTION OF ATLANTIS
Running time: 95 minutes. Not rated (nudity, sexuality). At Film Forum, West Houston and Varick streets.