This fall's 'Gemini Man' and 'The Irishman' are just the tip of the iceberg for how studios will look to capitalize on de-aging VFX techniques: "It's safer and cheaper than plastic surgery."

On July 23, Will Smith gave reporters an early preview of his upcoming thriller Gemini Man, in which the star fights with a younger clone of himself. The 50-year-old actor noted that, with advances in visual effects, he could sit back and let a digital double do all the work. "There's a completely digital 20-year-old version of myself that can make movies now," he quipped. While the comment got a laugh, it wasn't too far off from Hollywood's new reality: Actors can now play a character at any age — regardless of their own.

New VFX techniques could be used to tell stories that studios might not have attempted just a few years ago. It's not too difficult to imagine in the near future, say, a digital likeness of an Avengers star appearing in Marvel Studios' ever-expanding big-screen universe in perpetuity, even if the actor has long moved on from the role. And who profits from these digital copies of actors will likely spark union debates as usage grows more common.

This fall, two prestige tentpoles will test the waters for this new paradigm. In Paramount's Ang Lee-helmed Gemini Man (Oct. 11), "Junior" Smith involved creating a fully digital character that looks and acts like Smith did around 1996 when he starred in Independence Day. The character was created by VFX house Weta Digital to use in some of the most complex scenes where "Junior" has to act alongside Smith.

Meanwhile, Martin Scorsese's period drama The Irishman stars Robert De Niro, 75, as Frank Sheeran, a labor union leader and alleged hit man for the Bufalino crime family, and Al Pacino, 79, as union activist Jimmy Hoffa. Both actors (and others) will appear at different ages spanning decades, which is accomplished with VFX and makeup.

But it's the digital de-aging work, which is being handled by Lucasfilm's Industrial Light & Magic, that has been the focus of much curiosity, though specifics of the techniques used haven't been revealed. It’s become common for an actor to have their face and body scanned at the start of a project if VFX might be needed (for instance, in action films for a digital stunt double).

A believable, fully digital human is still considered among the most difficult tasks in visual effects. "Digital humans are still very hard, but it's not unachievable. You only see that level of success at the top-level companies," explains Chris Nichols, a director at Chaos Group Labs and key member of the Digital Human League, a research and development group. He adds that this approach can be "extraordinarily expensive. It involves teams of people and months of work, research and development and a lot of revisions. They can look excellent if you involve the right talent."

The VFX team must first create the "asset," effectively a movable model of the human. Darren Hendler, head of VFX house Digital Domain's digital human group, estimates that this could cost from $500,000 to $1 million to create. Then, he suggests, producers could expect to pay anywhere from $30,000 to $100,000 per shot, depending on the individual requirements of the performance in the scene.

More often, filmmakers use what has been broadly described as "digital cosmetics," which could be thought of as a digital makeup applications — for instance, removing wrinkles for smoother skin. This means that age is becoming less of an issue when casting an actor. "It's safer and cheaper than plastic surgery," notes Nichols. Marvel's Avengers: Endgame involved the creation of roughly 200 such de-aging shots, with work on actors such as Robert Downey Jr. and Chris Evans, to enable its time-traveling story.

AI and machine learning, and the related category known as generative adversarial networks (GANS), which involves neural networks, could advance this area even further. "I wouldn't be surprised if The Irishman and Gemini Man are the last fully digital human versions that don't use some sort of GANS as part of the process," Hendler says, adding that de-aging techniques and digital humans could start to appear in more films, and not just those with Marvel-size budgets. "I think we'll start to see some of this used on smaller-budget shows."

Adds Guy Williams, Weta's VFX supervisor on Gemini Man: "Once Gemini Man and The Irishman come out, you'll [have several] successful films showing how it can be done. When you give that possibility to directors, they will find new ways to use it."

This story first appeared in the Aug. 7 issue of The Hollywood Reporter magazine. To receive the magazine, click here to subscribe.