Park City • Two pivotal events in Ira Sachs’ teen years shaped his life and his art.

At age 15, Sachs came from Memphis, where he grew up, to spend some time in Park City with his father — a developer responsible for establishing one of this mountain town’s landmark hotels, the Yarrow. That was back when “Park City was a little hippie ski town,” he recalls now.

On that trip, young Sachs attended the United States Film Festival — the precursor to the Sundance Film Festival — in Salt Lake Ctiy’s old Trolley Corners theater.

“I grew up thinking there was something called independent film, which I wouldn’t necessarily have had access to if there wasn’t Sundance,” Sachs said in an interview.

Since then, Sachs and Sundance have been frequent friends. The filmmaker, now 46, has brought five films (three features and two shorts) to the festival, including the 2005 Grand Jury Award winner, “Forty Shades of Blue.” Sachs also has workshopped scripts at Sundance Institute labs, and served as an adviser there.

The other important event happened when Sachs was 16: He came out of the closet. Living openly as a gay man has informed Sachs’ filmmaking, from his 1997 Sundance entry “The Delta” to his current film at the festival, the romantic drama “Keep the Lights On.”

The movie follows a decade-plus relationship between two men: Erik (Thure Lindeblad), a documentary filmmaker from Denmark, and Paul (Zachary Booth), a publishing-house lawyer in New York. The movie traces the relationship from anonymous pick-up to committed couplehood — a commitment threatened by Paul’s addiction to crack.

The story, Sachs said, is loosely drawn from his own life, inspired by a long-term relationship that ended in 2007.

“On the last day of the relationship, I was aware that there was a first day, and there was a great story in-between,” Sachs said. “How these two men traveled this journey together, and what they learned, what they suffered, and what they discovered about themselves would make for a compelling story.”

The movie is raw in its emotion, and explicit in depicting Erik and Paul’s sexual activity. “We wanted to make a film that was not ashamed of sexuality, but also it’s not pornographic,” Sachs said. Sex, he added, is “as much a part of the story as the birthday party or the Christmas party. It’s part of what people do in life.”

One of the film’s working titles was “Shame” — the name now attached to Steve McQueen’s NC-17 drama about a sex addict played by Michael Fassbender — but, Sachs said, they tried to make the movie shamelessly.

“For gay people, we learned about our lives in secrecy and a lot of fear,” Sachs said. “I came out of the closet at 16, but that doesn’t mean I stopped having secrets. I think it’s interesting: What is the generational effect of the experience of being a gay person in America? For my generation, it was very difficult.

“I’m at the point in my life where my greatest strength is to be specific as possible to my own aesthetic and my own experience,” he said. “I think — I hope — I have learned that to be as transparent as possible in my life and my work allows me to be closer to other people.”

Sachs said he is inspired by other independent filmmakers, such as Kelly Reichert (“Meek’s Cutoff”) and Gregg Araki (“The Doom Generation”), who stay true to their idiosyncratic vision.

He knows that’s not easy. “It’s easy to make a film, but it’s hard to make a career of being a filmmaker,” said Sachs, who also teaches graduate students at New York University.

Sachs called Sundance— both the festival and the institute — “the most supportive element of my career.”