The technology that helped Will Smith battle a younger version of himself in 'Gemini Man'

I f making movies is a tiring business, then making movies that could forever change how movies are made is near exhausting. It's fast approaching 2am in Glennville, a suburb of Savannah, Georgia, and it's chilly. But most of its 5,000 residents seem to be wide awake and watching excitedly from the pavement as Will Smith shoots some bad guys off a roof in a hail of bullets, their flailing bodies crumpling into cars parked far below. A couple of hours later, with most of the locals tucked up in bed, Smith has become a little philosophical in between the bursts of machine gun fire . Existential , even. "When we get done with this movie, we'll end up with a perfect 23-year-old avatar of myself," he says, then smiles at all the possibilities running through his head. "That'll be crazy. I'll be able to make movies with a 23-year-old version of myself!" This, you see, isn't the set of just any Will Smith action movie. This is the set of Gemini Man , a movie its makers say is nothing short of the ultimate action movie – an unprecedented trinity of unrivalled spectacle, next -level performances and unparalleled audience immersion. As its director Ang Lee tells me, as Smith and his co-star, Fargo 's Mary Elizabeth Winstead, reset for another take: "We're not just doing something good here, we're discovering something new – a new concept of filmmaking. Five hundred years from now they'll look back and go, 'Oh, for the first 100 years [of making movies] they did that …' It's like silent movies, like sound, like colour. We went through all of that . This is another dimension." The first version of the Gemini Man script was written more than 20 years ago and became such a hot property in Hollywood that stars such as Tom Cruise , Mel Gibson , Clint Eastwood and even Sean Connery had a look at it . There was only one problem – the story was based on such an audacious idea, a concept so remarkable that the technology needed to tell it simply didn't exist at the time. "What we're doing here has never been done before," says Smith, as he primes us on the plot, and how his character fits into it. Or rather, how his characters fit into it. Because in Gemini Man , Smith does not only play the protagonist, a 51-year-old retiring hitman by the name of Henry Brogan, but the antagonist as well, a 23-year-old version of himself, called Junior – a clone of Brogan who has been sent to kill the hitman by some nefarious government types, when they realise that the only person who can kill a legendary hitman is a younger version of that legendary hitman. Someone just as deadly, but with better knees. Junior isn't simply some "de-aged " doppelganger, either, not like that weird young Captain Jack Sparrow they put in 2017's Pirates Of The Caribbean: Dead Men Tell No Tales , or that terrible animated Princess Leia that looked like something out of a video game at the end of Rogue One: A Star Wars Story a year earlier. Junior is a whole new digital human, one that will not only interact with, but fight his older self, in a series of increasingly eyeball-defying and epic action sequences across three continents (Cartagena and Budapest are equally significant locations). And both Brogans are being played by Smith . "This is not de-ageing, this is not face replacement – Junior is a completely digital creation, 100 per cent driven by Will Smith's performance capture," says Gemini Man 's visual effects supervisor, Bill Westenhofer. In other words, every tear Smith cries, every punch he throws , everything audiences see will be pure Smith. That was not an easy concept for the actor to get his head around. "When I saw the first test [that the filmmakers put together as a proof of concept], it was a freaky experience," Smith tells us of the moment he realised that this audacious plan might actually work. "I mean, it was me. I was looking at the perfect 23-year-old version of myself, like somebody took all the flaws out. I mean, it's a cool-sounding idea, right? But when you see it, it's cinematically astounding. When you see it, it gets inside of you. It's like, 'Oh, that's what cloning is …'" And if you thought James Cameron's 2009 film Avatar was the last word in cutting edge 3D, what makes Smith's double duty even more impressive is that Gemini Man is pulling all of this magic off on an entirely new, multidimensional canvas for cinema. Just as Lee has always pushed boundaries – in action choreography, with 2000's Crouching Tiger, Hidden Dragon ; in drama, with 2005's Brokeback Mountain ; and in digital technology, with his 2012 film Life of Pi – here he is shooting at a ground-breaking frame rate of 120 frames per second, in 4K, 3D HD. "Which sounds complicated," Westenhofer says. "But what it means is simple: the audience is [put] right in the middle of the action, with the actors." For those actors on screen, that meant "relearning" (Lee's word) the process of filmmaking in many ways . The pin-sharp detail in these new images is so immediate and immersive that audiences will be able to see even the changing blood vessels in their faces as the actors perform, meaning traditional make-up was banned on set. "I loved that because it was great to come into something, especially on a big movie, as a woman, that's totally different from what you would normally experience," says Winstead, later. "Normally it's like, 'Put on all the make-up . Cover her with everything .' But this is very stripped down. There's no pretence about it." Lee , who has poured everything he has learn t in almost 30 years of working in film into this pioneering step, has another way to describe it. He says watching his leading man's extraordinary performance felt like he had " found a new Will Smith". On set, the original Smith surveys his battle-strewn surroundings, bullet casings and bodies piling up all around, and digests his director's claim that this is a Smith we have never seen. "I couldn't have played these characters when I was 23 years old," he says . "But now I'm able to because of the amount of experience I've had and because of what Ang has discovered." Smith smiles, ready for one more take, maybe two, before the sun comes up on a new day. “This,” he says, “is going to change how movies are made and how movies are seen.” Gemini Man releases in UAE cinemas on Thursday, October 10

The technology that helped Will Smith battle a younger version of himself in 'Gemini Man'

Mark Dinning joins Will Smith on the set of ‘Gemini Man’, Ang Lee’s epic action movie that is revolutionising the art of filmmaking