How Disney's Lion King remake ripped up the animation rule-book

Jon Favreau is standing in the African savannah, eating a bowl of Rice Krispies. It's a little after nine in the morning, though the sun is unusually high, beating down on a rocky promontory that juts across the grassland. Standing up there is the multi-Oscar-nominated cinematographer Caleb Deschanel, who eyes the scene, then calls down to Favreau that the light isn't quite right, in a quieter voice than you'd expect.

"Change it?" murmurs the 52-year-old Iron Man director, at which point Deschanel, 74, reaches up, grabs the sun in his fist, and drags it downward. The sky instantly bruises and dims, and the promontory's shadow whips across the ground almost too fast to see, like a tablecloth pulled out from under the dishes. "Better?" asks Favreau. "Better," Deschanel nods, and starts sizing up his shot through a viewfinder.

In a sense, none of this is really happening. The two men are standing a few feet apart, wearing virtual reality headsets, in a large, matt-black warehouse numbered 5419, in the Playa Vista suburb of Los Angeles, in February 2018. But simultaneously, within a parallel digital realm, they're surveying a film set that doesn't actually exist.

Specifically, it's the set of Disney's new version of The Lion King: a reworking of the 1994 hand-drawn masterpiece that still stands as the high watermark of the studio's late-20th-century renaissance. In line with recent second swings at the likes of Dumbo and Aladdin, Favreau's film has been billed as a live-action remake – but it isn't, though nor is it animated, at least not in any remotely conventional sense.

"It's really a game we've created," Favreau explains, setting down his breakfast beside his director's chair and removing his headset. "A multiplayer VR filmmaking game, in which the objective is to make a movie."

Favreau was recruited late in 2016, while his partly live-action remake of The Jungle Book was closing in on US$950 million at the global box office, a sum that brought it just inside the 50 most lucrative films ever made. That success gave him leverage to demand the studio take the technological leap to what sounded back then – and, quite frankly, still does – like a ludicrously advanced new hybrid filmmaking method: a real-life crew shooting animated characters on virtual sets.

"The difference this time is we're playing with the house's money," he grins (the new film has a budget thought to be significantly more than even The Jungle Book's US$175 million). "So the only question is, how good can we make it?"

In many respects, the activity inside Warehouse 5419 resembles an ordinary film shoot. Crew members are busily adding sandbags to the dolly – a wheeled cart to carry the camera for a complex tracking shot – adjusting the weight for the smoothest possible movement. A giraffe-like jib for crane photography is propped up in the corner beside three jetpack-like steadicam rigs.

Yet a few key things seem to be missing: namely the actors, the cameras, and the set. Don a pair of VR goggles from the rack on the far wall, though, and all three are revealed. You'll find yourself standing beside Pride Rock, with the burnt yellow plains running to the horizon on all sides. Using a hand-held controller to rove around, you might then spot two creatures circling one another on the plateau: roughly modelled avatars of the young prince Simba and his Machiavellian uncle Scar, repeatedly walking through the scene that's about to be shot. (Recordings of the characters' voices, provided by J D McCrary and Chiwetel Ejiofor, ring out from speakers dotted around the warehouse.)

Hovering a few feet from the characters is Deschanel's virtual camera, which responds with nearest-millimetre precision to the movements of a fluorescent plastic puck that's attached to the dolly in the outside world. Meanwhile, his "shot" plays back on a monitor, with Simba and Scar stood fast as taxidermy, in first positions. Then Favreau calls "action" – and the animals start walking and talking, while the crew, all in VR headsets, slowly push both dolly and Deschanel down the camera track.

To ensure the image stays sharp, a focus puller has to toggle what looks like a volume slider on a mixing desk; there are other dials to tweak things like the shutter speed and aperture. The resulting footage isn't lifelike, or at least not yet: in its raw form it looks more like a high-end PlayStation 4 game. But then it's sent to London visual effects house MPC, which will buff it to a photoreal sheen.

The point of this genuinely mind-bending process is "to create the illusion that we're really filming real things", Favreau quietly explains. (Everyone here is quiet; it's by far the most serene set I've ever visited.) "The communication, even the accidents, are what make it feel natural."

To be clear, the goings-on in Warehouse 5419 feel anything but natural. But just a few months earlier, things were different. The shoot began with Favreau and his cast gathered in that same space – Beyoncé and Donald Glover, Seth Rogen and Billy Eichner, a returning James Earl Jones as Mufasa – acting out the entire film like a piece of theatre in the round.

Their dialogue was recorded and cut into what Favreau describes as "the radio play version" of the story, while videos of their performances were sent to the animators, who used them as reference footage while crafting the animal characters' movements. The priority, however, says animation supervisor Andrew R Jones, was "to take inspiration first and foremost from the way wild animals really behave. You have to elevate their status slightly, but without breaking their physicality by giving them obviously human-like gestures. We did some tests of that," he grimaces. "The second you push it too far it feels like a cartoon. Like it's no longer a living thing, but an object someone's puppeteering around."

Visually, Favreau drew inspiration from Deschanel's earlier work, particularly The Black Stallion, the 1979 boy-and-his-bronco adventure shot partly on location in Sardinia. "You evaluate shots differently from the days before CGI," says Favreau. "Nowadays, the minute you reach the VFX [visual effects] machine, you instinctually think, 'Let's put a perfect sky behind that perfectly lit close-up.' But though everyone might gasp at the result in the edit, it doesn't look like something you'd ever be able to shoot." Accordingly, he's found himself constantly telling his VFX team to "make it uglier… have the fast-moving characters go a little out of focus, cast awkward shadows, muddy the clouds up a bit."

David Attenborough's BBC documentaries were another inspiration – both for their observational shooting style and their use of music and editing to impose storylines on natural behaviour in the wild. "There's a common acceptance that this is how nature looks," says Favreau. "So we're trying to import that sense of realism by borrowing their techniques." He shows me a clip of a mandrill crouched on a rock, which I initially assume must have been culled from Planet Earth. Astoundingly, it is in fact a finished close-up of The Lion King's wily old shaman Rafiki, shot in the warehouse.

Favreau soon discovered that a basic fidelity to nature was non-negotiable. "If you'd asked that monkey to smile like a human, you'd have blown it," he says. "No matter how good your rendering."

"That's the challenge," Jones adds. "You can't just take the original animation and make it look real."

Some species turned out to be more camera-friendly than others. The lions themselves had a noble bearing and subtlety of expression that lent itself particularly well to close-ups, while the jittery hyenas and Zazu the punctilious hornbill, voiced by John Oliver, proved trickier. "We're still landing on exactly how his beak is going to work," says Jones, frowning.

Yet even that paled in comparison to the challenge of integrating Elton John and Tim Rice's well-loved songs, which feature in the new film in full – though no one will confirm or deny, even off the record, whether Eichner's version of Timon the meerkat will dress in drag and do the hula, as Nathan Lane's did. The two show-stoppers, Circle of Life and Can You Feel the Love Tonight, weren't a problem, since they play over dialogue-free sequences.

But more character-driven numbers such as Hakuna Matata and I Just Can't Wait to Be King have been testing in the extreme. This time, on the latter, the option of snapping into a pastel-coloured Busby Berkeley daydream was never an option, and production designer James Chinlund describes experimenting with wide-angle lenses "held down at paw level", to recreate a comically exaggerated cub's-eye-view of pride land life.

As for the Hakuna Matata moonlit strut, Chinlund goes on, "that's sacred terrain. You can't not do that." So he and a camera crew spent nights in the Mohave Desert working out the precise conditions under which you could silhouette a big cat, a warthog and a meerkat against a full moon, so they could be recreated in Warehouse 5419.

"You'd be amazed by how much the boring things matter," Favreau says. "The way different-sized rocks are scattered in canyons, the paths carved by water, the light on fur. When you get all these things right at once, it's like seeing a really good magic trick. Your brain can't process what's actually going on, so emotion takes over."

He tells a story about the illusionist Max Malini, who used to cover a coin with an onlooker's hat, then lift it up to reveal, of all things, an enormous block of ice. "Where did the ice come from?" he hoots. "There's literally no way to figure it out. So all it's possible to do is smile."

LOWDOWN
Who: Director Jon Favreau
What: The Lion King
When: In cinemas next Thursday