Thirty years since Forrest Gump's lifelong love for childhood sweetheart Jenny gripped the globe and won the Academy Award for Best Picture, actors Tom Hanks and Robin Wright have reunited with director Robert Zemeckis for Here, another love story spanning decades.

"It was like the 30 years had never passed," says Hanks. "And yet, we took a few minutes to note that 30 years had passed ... We had to have a couple of minutes to say, 'Can you believe that we get to do this?', celebrating the joy, love, and excitement of taking another shot at it."

"[But] we picked [up] right where we left off because we speak this special language and we all signed on for a very specific chore of trying to figure out how to make this movie."

Chore might not be the most inspiring choice of word to describe a film, but Here required a lot of thought – and cutting-edge technology – to come together.

Adapted from Richard McGuire's graphic novel of the same name, Here is an unconventional story, a series of tableaus in one small space across thousands of years, with each panel drawn from the same physical perspective. After a house is built over the space in 1910, we're inside a living room for much of it, following the various families that call it home.

To stay true to the graphic novel, Zemeckis decided that Here would use a single static camera shot throughout the film. After all, he loves a challenge. Since the 1980s, Zemeckis has been an advocate for innovative visual effects or techniques, whether that be Back to the Future II's use of computer effects, Who Framed Roger Rabbit's mix of live-action and hand-drawn animation or the content-capture technology used for The Polar Express.

"After I decide to make a film, I'll sit with my team and say, 'What's the most interesting way we can present this scene? What's something that we can do that maybe the audience has never seen before?'" says Zemeckis.

Instead of new angles, pans, zooms or cuts, panels pop up with new footage, eventually fading over the scene – just as overlaid panels offer windows into multiple timelines at once in the novel. The unique approach meant that each scene had to be shot in full with no breaks or edits, where two different takes could be spliced together to cut a slow line or a prop issue.

"Sometimes, we could nail it in three to five takes," says Wright. "Sometimes we had to do 45 takes just to get it perfect with our rhythm. Because we're not cutting, we don't have that luxury of coverage [to] save bad performance, which is kind of what it can do, right? So we had to nail each take."

"The truth is, we could have made this movie the way anybody makes this movie," says Hanks. "We could have had close-ups and locations, all the coverage and the masters … But Bob thought the best way was to have time, if this makes sense, be the only thing that moves on screen. Space doesn't."

A millennia of life

Here may begin with dinosaurs, feature a pre-colonial Native American romance and include a housekeeper contracting COVID, but its main focus is the Young family, who move into the home in 1945.

With Al (Paul Bettany) returning from war, he and wife Rose (Kelly Reilly) start a family. Shortly after their oldest, Richard (Hanks), introduces them to high school sweetheart Margaret (Wright), Margaret falls pregnant. A living-room wedding (and birth) follow, and the young couple adjust to their unexpected life together: Richard trades in dreams of being an artist to make a living as a salesman, while Margaret has yet to even grasp what her future could look like before it shifts.

Hank and Wright play the couple from their teens to twilight years, with Here using generative AI technology to digitally de-age and age-up its actors, who are 68 and 58, respectively, in real life.

Called Metaphysic Live, the technology mined interview footage of the duo across their careers to create instantaneous special effects, with two monitors on set to showcase both the raw footage and the digitally altered version.

Hanks says it was "shocking" at first to see himself 50 years younger, but also useful having real-time feedback to nail the physicality of a particular age. "It was really cool for about a minute and a half, but then all we ended up was seeing the work that that we had to do," he says.

"It's amazing how both of us became very technical right off the bat," Hanks says. "'I need to have better posture.' 'You have to get off the couch a little bit faster than you did.' 'We have eyes that know too much, we have to figure out a way to remove that jaded-life quality from them.' 'We have to speak faster.'"

Given the film spans Richard and Margaret's life, it shows how people shift and grow without intending to – and just how quickly a life can go by. Hanks says the film made him reflect upon his own mortality, jumping between decades and feeling the difference.

"Here's one of the things you find out when you get a little bit older. Time is finite," he says. 

"Hopefully I get up about 5:30 or 6 o'clock because I know the day is only 24 hours long. Still, when I go to bed at night, I think, 'I'm not sure I got done everything. I'm not sure I thought everything I wanted to think. I'm not sure I said everything I wanted to say today. Did I read enough? Did I create enough? Did I share enough with the people that I love?'"

"Time is running out for a guy like me … I'm not afraid of the fact that it's running out, but I am very much aware ... this thing does not go on forever."

The ethics of generative AI

Here's use of generative AI arrives as Hollywood grapples with the ethical use of it in filmmaking when it comes to scraping copyrighted images or text without just payment. A major demand of the SAG-AFTRA union strike of 2023 was ensuring guidelines around the use of AI in recreating an actor's likeness or generating scripts from existing work, and the union's voice actors are currently on strike with major video game companies over similar concerns.

Metaphysic, the US studio behind Metaphysic Live, brands itself as an "ethical" generative AI company, with practices around consent and data protection, as well as protections around usage in projects involving minors. It was recently used in sci-fi horror Alien: Romulus to recreate late actor Ian Holm's likeness for a version of his character in the original 1977 film – a controversial move that some deemed disrespectful and eerie, despite sign-off from the actor's estate.

Still, the tech inspires existential questions around art and entertainment, with artists questioning the purpose of watching something that has little to no human spirit. As a public figure, Wright notes she's concerned about non-consensual deepfakes, but believes that AI-generated tech is simply a tool for actors and creators.

"I don't think it will take over actors, because I don't think it would ever be able to have the heart and the true emotionality that a human can have," she says.

Zemeckis agrees, preferring the term "digital makeup" to describe Metaphysic Live's use in Here. When asked about the future of AI in Hollywood, he's reluctant to give a definitive answer.

"I don't know," he laughs. "There are many things that AI is going to do which we can't think of. What I learned from making a movie about the future is that we always underestimate it when we try to predict it."

Here is in cinemas now.