In the tradition of great music movies, One Direction’s feature-film debut has sex, drugs and rock ‘n’ roll — just without the sex or the drugs.

The Morgan Spurlock-directed 3D documentary One Direction: This Is Us hangs out with Harry, Louis, Liam, Niall and Zayn backstage, at home and on the road, and comes to the conclusion that the five well-coiffed lads who have conquered the world are, well, pretty nice.

Spurlock — who made his name with socially engaged documentaries such as Super Size Me and Where in the World Is Osama Bin Laden? — is on a mission to convert unbelievers (and even Beliebers) into One Direction fans.

“These boys are so charming and so fantastic, I challenge you to go to the movie and not like them after the film is done,” Spurlock said on Monday at a news conference with the band ahead of the movie’s world premiere yesterday in London.

“Part of the reason they’ve been so incredibly successful with their fans is that they are so incredibly grounded and normal, and that’s what comes off in the movie. ... You see five guys who are the same five guys they were three years ago.”

Three years ago the five teenagers auditioned individually for TV talent show The X Factor, where svengali Simon Cowell had the idea of putting them together as a boy band.

They didn’t win the competition, but they went on to top charts and win young hearts around the world with their cheeky personalities and ever-so-slightly edgy pop.

Part concert movie, part behind-the-scenes documentary, This Is Us follows One Direction on the road, from London to Tokyo to Mexico City. It promises to show the group as fans have never seen before — up close, personal and in 3D.

Spurlock was given access to the band members’ families as well as to the band members themselves at home, in hotel rooms, in stadiums and on tour buses — though it’s unlikely to be a completely candid, warts-and-all look at the band. Cowell is a producer on the movie, which is aimed firmly at the young global army of “Directioners” who helped make the lads stars.

Spurlock has said he was drawn to the movie by the chance to experience the closest thing our decade will see to Beatlemania.

“You suddenly realise it isn’t just a British or an American phenomenon,” he said. “Everywhere they go they are being chased by hordes of fans. We were in Mexico City and there’s 5,000 people camping outside the hotel. This is such a massive global phenomenon, and it’s only growing. It was incredible to see.”

For the band members, whose feet have barely touched the ground since 2010, it was a rare chance to reflect on how far they’ve come.

Because so much is happening to us you kind of just lose it all,” said Louis Tomlinson. “It’s great just to sit back and watch it back and remember and relive those moments.”

Band mate Liam Payne said making the film had been “nerve-racking.” But the lives of the five young men — none of them over 21 — have become so surreal that the experience of being filmed offstage and even in bed was almost normal.

“In a way it was really strange having the cameras around, but at the same time it didn’t make that much difference,” said Harry Styles. “It was kind of just getting on with your day while having someone in your way when you’re trying to get out the door.”

The band members gently deflected questions about whether scenes of partying or other debauchery had been left on the cutting room floor.

“We like to think we’re rock ‘n’ roll, but we’re not, really,” said Tomlinson. “It’s a shame.”

One Direction: This Is Us opens in Britain on August 29 and in the United States on August 30.

FAMILY-FRIENDLY REPUTATION

The five singers told a news conference in London on Monday that This Is Us allowed them to present themselves in a more realistic manner than they are depicted on videos, in concert and on the ubiquitous social media sites that track their every movement on and off stage.

“There is only so much you can get across in terms of your personality, you know, social media and like 10-minute interviews you do with people,” singer Harry Styles said.

“So I think ...(it’s) a way for us to get across what we are like and what we are like with each other for the fans to see.”

Styles laughed off one reporter’s question about whether footage with groupies or drugs had been edited out.

“This is a family press conference,” Styles said.

Spurlock said the film would show that part of the band’s success stems from their down-to-earth personalities.

“Part of the reason I think they have been so successful with their fans is that they are so incredibly grounded and normal and that’s what comes off in the movie, there’s no air of superiority,” he said.

‘WE’RE NOT CELEBRITIES’

One Direction have conquered the global market with two albums and a string of catchy hit singles.

They said in May they are working on a third “edgy” album and will embark on a world tour next year.

In an interview with Reuters TV on Monday, Zayn Malik said certain aspects of fame took the band by surprise.

“We never wanted to have the title ‘celebrity,’ we just want to be normal lads in a music band. We’re not celebrities, we’re just in a band,” the singer said.

Horan added that the documentary helped the band members themselves process the phenomenon that One Direction has become.

“Because we live in this bubble ... we don’t get to see exactly what it’s like because it’s happening to us,” he said.

The band has a devoted following of fans around the world mainly comprising teenage girls, including 14 million Twitter followers, and Tomlinson said he felt a certain responsibility to the young fan base.

“Being put in this position, you almost feel with the likes of Twitter, you almost feel pressured to be that role model, and it’s kind of balancing that and meeting in the middle,” he said.