One Direction have pledged that their 3-D movie release, "This Is Us," will let fans in on everything from the band's ups and downs to their ... bathroom activity.

So with cameras rolling on Harry, Louis, Liam, Niall and Zayn's most intimate moments, did they have any reservations? "This Is Us" producer (and "Best Song Ever" video director) Ben Winston recently revealed to MTV News that the guys actually weren't too uptight when it came time to film.

"The advantage that we've got to make a film about these artists is that they grew up in front of the TV cameras. They became artists on the 'X Factor,' and therefore they were used to having cameras with them at all times," Winston explained.

"So I think they were comfortable with [sharing]. They've known me for quite a few years. They got to know [director] Morgan [Spurlock] really well and they got to know the [rest of the crew]. We're a close unit [and] team and, therefore, we all felt like part of the gang."

While Spurlock — whose credits include the documentaries "Super Size Me" and "Where in the World Is Osama Bin Laden?" — might seem like an unusual choice to bring 1D's story to the big screen, Winston said he was the perfect director to capture the fellas behind One Direction. And though the movie will document their ups and the downs, Spurlock confirmed this week that those moments won't include Harry's 2012 romance with Taylor Swift.

For Winston, working with Spurlock was just "a great experience."

"I think Morgan has really enjoyed being on the road with the boys," he said. "I think that that we've got a film that really shows who they are and what they can do and it shows off their talent. We've been everywhere. That's the thing: We've been everywhere with them, across the way from Japan to Mexico to L.A. It's been a great experience and I hope people really love the film."

Winston has grown close to the band, even collaborating with the guys on their 2011 doc, "One Direction: A Year in the Making." And according to him, fame hasn't changed them at all: "The most amazing thing is they have remained incredibly normal and humble and caring and considerate ... they are incredibly normal and incredibly lovely and are very grateful for the opportunity they've been given."

"This Is Us," hits theaters on August 30.