Richard Linklater has admitted it wasn't always easy working with his daughter Lorelei on new film Boyhood.
The acclaimed director's new film, starring Ellar Coltrane as Mason, was filmed over 12 years, charting a boy's life as he grows up from five to 18. The Before Sunset director cast his daughter as Mason's older sister Samantha.
Richard revealed: "There were moments when I felt it wasn't an actress-director relationship, it was a father-daughter thing, but it was great. It was a fun thing to be doing with her every year, and it didn't feel like a movie, it was just something cool we did.
"That's what I do, and she's grown up around it, she's a good actress."
The film - which also stars Patricia Arquette and Ethan Hawke as Mason's parents - was shot for about three days every year, and the writer and director admitted it was a logistical challenge to co-ordinate everyone's schedules each time.
Richard also confessed it had been a challenge to persuade a company to financially back a film that would take 13 years to make, but added: "I got lucky."
The director admitted casting Ellar as Mason was the most important part of getting the project to work.
He said: "I just went with the kid who seems the most interesting, I thought he'd be an artist of some kind, cool parents."
He added: "He's the same kind, ethereal, thoughtful, mysterious young man as he was when he was a kid. Same guy."
Richard previously worked with Ethan on the Before trilogy with Julie Delpy, about two lovers who met on a train and spent a day together in Vienna in 1995's Before Sunrise. Before Sunset came out nine years later and saw the couple bump into each other again in Paris and consider what might have been. The final film, Before Midnight, captures the couple after starting a family and living together for several years.
The director admitted: "Time has played a big part in my narratives. It's funny, that film came out last year, the third in that trilogy that covers 18 years... this being 12... I guess I think a lot about time in cinema."