PARK CITY, Utah — When Ellar Coltrane was growing up in Texas, his friends would razz him about a movie he claimed to be shooting with the director Richard Linklater. Over the years, they would ask Coltrane if it was ever coming out, and why he was always disappearing to allegedly "make a film" with the man behind "Before Midnight" and "Slacker."
"Some people had a hard time grasping what was going on," the 19-year-old said.
No wonder: Since he was 7, Coltrane has been involved in an audacious — and patient — feat of filmmaking.
Every year, Linklater and a film crew would whisk him away from his Austin home to another set of Texas locations and ask him what was happening in his life. Then they would put him together with a fake family that included Ethan Hawke, Patricia Arquette and the director's daughter, Lorelei Linklater. Finally, they would shoot scenes from both a script Linklater had written and the boy's own year, merging it into a character called Mason.
They did this for nearly a week every year until last year, when Coltrane turned 18.
Child actors are a dime a dozen in Hollywood. But none have had, and perhaps none will ever have, the experience of Coltrane. He is the boy at the center of "Boyhood," Linklater's ambitious 12-year project to follow a child growing up in real time, in what might be called a sprawling epic of the intimate.
The movie is scripted, but its story was adjusted over time as Coltrane changed. Linklater then blended it all into a single three-hour narrative film, which premiered this week to rave reviews at the Sundance Film Festival and will be released in theaters later this year.
The festival screening ended at nearly 1 in the morning, followed by some spirited celebration at a local resort. The next day, Coltrane was running the gantlet of photo studios, mike-in-face questions and the general frenzy of Sundance.
"It's very strange. I've been on the set side of things, but not really on this one," Coltrane said of the star-making machinery. "I felt a little like an alien from another planet."
Linklater knew he wanted to capture the transition from youth to adulthood. But he was initially unsure of how to go about it.
"I wanted to do something about childhood. But I couldn't find one moment I had enough to say about," Linklater said. Then he had a thought: "Why couldn't you just film a little bit each year and encompass all of it?"
Although the movie was essentially made as a series of snapshots, it plays as it would in real life. Basically, audiences are watching the aging process naturally, not with the makeup, swapped-out actors and other Hollywood fabrications.
In spanning such a long period, the film also takes a look at the changing culture. Music evolves over the course of the film — from Coldplay's "Yellow" at the start to Daft Punk's "Get Lucky" at its end. The war in Iraq gives way to President Obama's election. Mason's Game Boy subtly evolves into a Wii and then into an iPhone.
Linklater has long been interested in the larger theme of the effect of time's passage on the human psyche; after all, his "Before" series (it also includes 1995's "Before Sunrise" and 2004's "Before Sunset") has explored a fictional couple over an 18-year period, checking in on them to see how they, and we, had changed.
In "Boyhood" he did something similar, though by examining childhood, marriage and intergenerational dynamics, it's an even broader exploration of how the years can both sharpen and warp our thinking.
"The real character in the movie," he said, "is time."