“Big action spectacles are the only films that seem to make studios comfortable enough to use this level of artistry and technology in storytelling,” Favreau said. “And so the unique opportunity I’ve had is to use it for humor and emotion. Showing nature, showing animals—and really getting into that deep, mythic imagery, that always marries well with technology and always has. And so that’s fun for me.”I first met Jon Favreau when he was promoting Zathura, his largely forgotten kids adventure movie. At the time he was very proud of his reliance on practical effects, on avoiding CG to whatever extent he could. That was what he liked, he told me - effects that seemed tangible.

Flash forward a decade and things have changed. Disney assembled a bunch of journalists at the El Capitan theater in Hollywood to look at footage from Favreau's upcoming live action Jungle Book, a movie that features no practical effects. In fact it features almost nothing that is real, except for the kid playing Mowgli. Every blade of grass, every flying bug, every hair on every animal's back is CGI. Favreau shot the whole thing in a studio space in Downtown LA, with only the most minimalist sets - dirt paths, stones on the ground - for young actor Neel Sethi to interact with.

The footage presentation began with some proof of concept stuff - a bird on a branch. It was, in a word, stunning - this looked like a real bird, including in its movements. If Favreau had told me had shot this bird in his backyard I would have believed him... which raises the question 'Why not just shoot a bird?.' Favreau explained that the difficulty in getting a bird to step and move exactly the way you need it to step and move in a scene makes working with real animals even more expensive, which I believe is George Lucas' attitude about working with actors. At any rate, the bird was incredible, and only the beginning.

Favreau did that thing nervous perfectionists do when showing off a work-in-progress, telling us that the FX were still being tweaked and this wasn't a final version. But as is always the case with nervous perfectionists, he was the harshest critic in the room - what we saw wasn't flawless but so close as to be indistinguishable from flawless. The first footage we saw was of The Water Truce, in which a drought lowers the level of a lake in the Indian jungle to such an extent that the Truce Rock appears, signalling to all the animals that the watering hole is now a safe zone. Anyone can drink there without being worried about getting et up. The shots were magnificent - swooping looks at the watering hole, absolutely photo-real animals coming together to drink, and then in came trouble - Shere Khan, the mighty tiger voiced by Idris Elba.

If there was anything imperfect in this moment it was that Shere Khan wasn't leaving footprints in the mud, but who notices that when everything else is so incredible? I don't want to make grand proclamations about the quality of Jungle Book - I remember io9 calling The Good Dinosaur a 'masterpiece' out of an early press day- but I will say that what I saw in the El Cap was entirely the next level in animation. Each of the animals was completely real, and Shere Khan was absolutely totally real - even when he began talking. That was the big question for me, would the animals speaking break the spell? Would they suddenly become too anthropomorphized? But with Shere Khan it was like magic - I was looking at a talking tiger. Favreau explained that he and his FX team looked at pretty much every talking animal movie - including Dog With A Blog! - to what did and didn't work. There was a lot of trial and error with the animators, a lot of dead ends pursued before they hit on the perfect animation for each animal to make them like they were truly speaking.

In fact the only problem footage in the whole presentation featured the live human. In some scenes Mowgli was so clearly composited into the scene it was distracting - here was a complete, gorgeously lit and fully realized living world... with a live boy pasted into it. I have to assume that this will be fixed by release, although I have long found that compositing live elements into animated elements to be the weak spot in our modern FX infastructure. Sethi's acting in general might be the film's weak spot; every celebrity voice was wonderful, but Sethi often had the helpless broadness of a kid mugging for the camera. That is a not inconsiderable weak spot, although we will have to wait for the film to pass judgment.

The movie itself is kind of a hybrid of the Disney cartoon and the original Rudyard Kipling book. For Favreau the cartoon is part of his DNA, and he wanted to try and recapture the experience of watching that movie, which was slightly surreal and charmingly odd. At the same time he wanted to go back to the original Kipling, and he worked in quite a few nods. One absolutely wonderful sequence sees Bagheera, the black panther who protects Mowgli, telling his young ward to bow as a group of elephants walk by. They made the jungle, Bagheera explains, and they are like gods. It's from the original book and it adds to the tapestry of a living yet mythological jungle.

Speaking of mythological: Favreau ran into trouble with King Louie, the orangutan. The problem was that there are no orangutans in the Indian jungle; Walt Disney just threw one in there because he wanted one. But Favreau discovered that the Indian jungle was once home to Gigantopithicus, an enormous missing link. In this movie King Louis is a Gigantopithicus who outlived the rest of his people, a cryptid in the jungle, living amidst the ruins of an ancient civilization. The Giganto part of the creature's name ain't fooling around - King Louie in this movie is enormous, perhaps 15 feet tall. And with the voice of Christopher Walken.

The presentation was very special because we had a chance to see the film in a new kind of laser 3D, one that is so bright it eliminates my usual complaint about 3D glasses. Looking through the glasses I still found every frame as vibrant and colorful as they were without the glasses. It was an experience that reminds me that 3D doesn't have to be a horrible pain in the ass the reduces the quality of the film I'm watching. The only problem is that almost no one on Earth will see it in that format - Favreau explained that only a handful of theaters would have the laser technology in time for The Jungle Book's opening weekend.

But even though most people will end up seeing the film in an inferior way, Favreau feels the 3D is vital to the experience, and is a big part of why he wanted to make the movie in the first place. After seeing Avatar and Gravity he believed that the format was just as important to the experience as anything else in the movie. “I felt like I was missing out if I wasn’t seeing it that way," he said. Gravity in particular shaped how he approached The Jungle Book - instead of allowing the shot and the lighting to dictate the FX, he allowed the FX to dictate the shot and the lighting. The computer generated animals and landscapes became the stars of the movie.

It's easy to think that Favreau is getting caught up in the tech end of it, a fate that has befallen many a modern director who finds themselves deeply immersed in digital cameras and bleeding edge FX. Favreau insists that he's using all of this tech for the right reasons. “You have to breath life into this thing,” the director said, “otherwise it’s just an exercise in technology. It needs to have a beating heart in there, and that is what your cast brings you.”

That beating heart will be important, as The Jungle Book is quite different from many of its big FX antecedents like Gravity and Avatar - it's not a huge action movie. There is action - we saw an extraordinary chase scene that takes place amid a herd of stampeding water buffalo - but that isn't what The Jungle Book is all about. It's about Mowgli and the beasts he befriends in the jungle. Favreau knows that he's lucky to be able to make a movie like this with this sort of budget and to have access to this sort of technology.

“Big action spectacles are the only films that seem to make studios comfortable enough to use this level of artistry and technology in storytelling,” Favreau said. “And so the unique opportunity I’ve had is to use it for humor and emotion. Showing nature, showing animals—and really getting into that deep, mythic imagery, that always marries well with technology and always has. And so that’s fun for me.”