John Lasseter is standing on the main stage of the Anaheim Convention Center in California in front of thousands of cheering Disney fans. It's August 2015, the opening day of D23 Expo, Disney's biennial fan event, and the audience is a sea of Mickey Mouse ears and Frozen princesses, Star Wars lightsabers and Captain America shields.

A 58-year-old with round rimless glasses, an open, friendly face and the figure of Lots-o'-Huggin'-Bear, Lasseter is chief creative officer of both Pixar and Disney Animation Studioses. But here, a stone's throw from the original Disneyland, the fan reactions might lead you to believe you were witnessing the second coming of Walt himself.

Who can blame them? Since 2006, when Disney acquired Pixar for $7.4 billion (£4.85bn) and installed Lasseter and Pixar president Ed Catmull to impart their creative culture on its own faltering studio, Disney Animation has gone from turning out forgettable flops such as Home On The Range and Brother Bear to making critical and commercial mega-hits such as Tangled, Wreck-It Ralph and the highest-earning animated film of all time, Frozen. "It's amazing what is happening in animation at the Walt Disney Company. Two incredible studioses," Lasseter says. He's talking to the audience, but also to his colleagues from Disney and Pixar, who pack the front section. "I'm so proud of this place." After previewing Disney's upcoming slate -- including a crowd-frenzying appearance from Dwayne "The Rock" Johnson to promote Moana -- Lasseter turns to Pixar.

"For the first time, we have not one original Pixar feature film coming out this year, but two," he says. "And beyond those two films, we have the strongest slate of films we've ever had." Lasseter is exuberant; after disappointing reviews -- at least by Pixar's absurdly high standards -- for 2011's Cars 2 and 2013's Monsters University, this spring's Inside Out has been a phenomenal success, earning more than $770 million at the box office (Pixar's second highest ever) and receiving the studio's best reviews since Toy Story 3 (2010). If this month's The Good Dinosaur, released on November 27, is anywhere near as successful, there's a good chance that Pixar's toughest competition at the Oscars this year will be itself.

By any standards, Pixar's success rate is astonishing. Consider: the company has made only 15 feature films (The Good Dinosaur is its 16th). Of those, seven have won the Academy Award for Best Animated Feature (the studio with the second most wins, DreamWorks, has two); in total, Pixar has won 12 Oscars and gained another 30 nominations. Combined, its output grossed more than $9 billion worldwide and films such as Toy Story, Finding Nemo and Wall•E have given us some of the most enduring cultural touchpoints of the last 20 years. Clearly, Pixar has a secret, and that secret is now working wonders at Disney Animation, too. The question is: what?

On stage at D23, Lasseter finishes his Inside Out presentation, then moves on to talk about Pixar's latest film: The Good Dinosaur. "I love this film," he says. "It's gone through an amazing transformation." What most of Lasseter's audience doesn't know is the full extent of that transformation during its five-year development. The Good Dinosaur has proved itself to be one of the studio's most challenging films ever. For anyone interested in learning the secret to Pixar's success, it's a good place to start.

From the outside, the history of Pixar reads like an unrivalled run of successes. But, peering inside, a truer history of Pixar might be described as a repeated string of failures, occasionally punctuated by the release of a hit movie.

Embracing failure is a business cliché, but Pixar's unique approach to failure -- to pursue it obsessively throughout the creative process, embrace it and in doing so create films that never fail -- can be traced back to 1999's Toy Story 2. Disney, which in those days distributed Pixar's films, had initially ordered Toy Story 2 as a direct-to-video release, but Lasseter and Catmull refused to compromise on quality and pushed for it to be shown in cinemas. As the release approached, Pixar's senior team -- who had been busy making A Bug's Life (1998) -- realised the film was in terrible shape. With nine months until deadline, the studio decided to perform an overhaul. Staff worked late into the night, seven days a week, rewriting the film. The effort wasn't in vain: Toy Story 2 ended up being yet another hit. The gruelling episode has attained almost mythical status within the company, and has been followed by a string of similar resets. When a Pixar film doesn't reach its own high standards, they start over. "One of the things that happens with every Pixar film is that every single one of them is crazily difficult to make to the point where they're pretty much a disaster most of the time," Lasseter says, sitting in the lobby of Disneyland's Grand Californian Hotel the morning after his presentation. "We are always having to make changes to the story. But we don't panic. We trust the process and trust ourselves that we'll work through."

In the summer of 2013, Pixar was in another such crisis. Its next original film, The Good Dinosaur, wasn't working. Many of Pixar's films start with a simple "what if" premise, like "what if toys were alive?" The new film, pitched by Bob Peterson, a Pixar veteran who co-directed Up, was equally simple: what if the asteroid that killed the dinosaurs had missed Earth? The story focused on Arlo, a young apatosaurus, and a human boy named Spot. In the film, dinosaurs evolved to be talking, social creatures but humans remained primitive. "The vision from the beginning was to do a 'boy and his dog' story," says Lasseter. "I loved the idea. Pixar doing a dinosaur movie? This will be fun." But after three years in development and with only a few months before its scheduled May 2014 release, the film had lost its way. "It had become complicated," Lasseter says. "This happens a lot. You drown in complicated thoughts and you don't have time for personality and character and emotion." Even worse, the film-makers had lost confidence in it.

Lasseter and Catmull made a drastic decision: to push back the release date until November 2015, and redo the film from scratch. Pixar operates on releasing one original film a year and a sequel every other year. Delaying The Good Dinosaur meant that 2014 would be the first year without a film since 2005. For Pixar, Catmull says, delaying was an important statement. "You're signalling to people inside and outside the company that we will do what it takes to make sure the films are very good. That's what makes this place different," Catmull says. "What's interesting about Pixar is that the morale of the studio is directly connected to how everybody feels the movie is creatively," Lasseter says. "If their gut is telling us it's not good enough yet, we feel it. And that was the feeling with The Good Dinosaur. We were all looking at it, we just couldn't put our finger on it, but it wasn't quite working. That's when we shifted it around."

The first step was to replace Bob Peterson as director. Although changing directors is rare (and often messy) in Hollywood, Pixar films often experience crew changes midway through production: Toy Story 2, Ratatouille and Brave underwent similar changes. "After a while you can get worn out, and the people in the middle of it lose perspective. At that point, it helps to bring in fresh voices," Catmull says.

A softly spoken, grey-bearded West Virginian, Catmull didn't just found Pixar: he pioneered the computer graphics that made its films possible. He's also known for his deft approach to management; his bestselling 2014 book Creativity, Inc, written with Amy Wallace, was widely praised by many CEOs, including Mark Zuckerberg, for its candour and creative insight. ("Ed is kind of everybody's Dad," Lasseter says.)

Starting over on such projects is difficult, he says, but vital for the creative health of a company. "You can fall into the trap of not wanting to hurt somebody's feelings," he says. "Getting the story right is the most important thing."

To replace Peterson, Lasseter chose Pete Sohn, a long-time Pixar artist who had directed the short Partly Cloudy in 2009. Sohn, a boyish 38-year-old New Yorker, also provided the visual inspiration for Russell, the boy scout in Up; like Russell, he has an eager demeanour and is rarely seen without a baseball cap.

Sohn had been a story artist on the initial draft. Now, Lasseter entrusted him -- a first-time feature director -- to rescue The Good Dinosaur. "We don't assign directors to movies; we bet on people who are great storytellers and want them to reach into their potentials," Lasseter says. "I plucked Pete out of story and animation because of his charm and incredible humour. I said, 
'I think you'd be great at making movies.'"

Sohn, along with veteran Pixar producer Denise Ream, Inside Out writer Meg LeFauve and new head of story Kelsey Mann, went back to the original pitch and began conceiving an entirely new story. To do so, they retreated to a small conference room, known as the War Room, and started thrashing out ideas. "It was about boiling it down, and trying to find that one emotional core of the story," says Sohn.

"We knew that fundamentally we still wanted to tell a 'boy and his dog' story," says Mann, who worked in TV before joining Pixar for Monsters University. "We kept some small bits and pieces but everything else we started fresh."

Pixar is based in the small industrial town of Emeryville, 15 minutes' drive across the Bay Bridge from San Francisco. A giant Luxo lamp and ball -- the stars of the studio's first ever short, 1986's Luxo Jr. -- stands proudly outside the main building.

Designed by former Pixar CEO Steve Jobs, and renamed after him in 2012, The Steve Jobs Building is laid out to foster serendipity: a sprawling central atrium houses a café, post room and screening rooms, the idea being to encourage colleagues 
to bump into each other and spark conversation. (Initially, Jobs had only wanted two bathrooms, one for each sex, also in the central atrium. This was deemed a design too far.) "You really do have chance encounters at all times," says Catmull, sitting in his office. (Catmull's modestly styled space couldn't be more different from Lasseter's office next door, which is lined floor to ceiling with toys and model train sets.) "The other thing that works about it is that if something good happens, then the structure of the building means the energy affects the whole place."

Animation takes place on the ground floor in the Lower East Side (the building, and the entire Pixar campus, adopted New York nicknames early on). Employees are encouraged to decorate their workspaces -- in the nooks and hallways are offices decorated like ornate temples, a Mexican taquería and an aeroplane crashed in a jungle. The spaces between the offices hide bars, hangout areas, and a stage for employee bands. It's a creative nirvana.

The campus also includes several other buildings, a football pitch, pool, basketball court and gym. There's also Pixar University, which trains employees and offers creative pursuits, with classes ranging from painting to t'ai chi.

The War Room is on the Upper West Side. The walls are covered in Post-Its, scrawled with notes and sketches of every scene, and its current status in the animation process.

The new pitch had a simpler premise: after losing his father, Arlo is swept away in a river and washed up far from home. There he meets Spot, who helps him return. The pitch -- clearer and with a rich emotional core -- was approved.

The next step in making any Pixar film, before the real story work or any art can begin, is research. Lasseter is obsessed with it. "I drive every team to do exhaustive amounts about whatever story. I will send them to every corner of the globe," he says. On the family road trip that inspired Cars, for example, Lasseter found himself photographing the cracks in the asphalt along Route 66 ("I'm sitting on the side of the road taking pictures. It's nutty.").

For Ratatouille, the film-makers trained as chefs in three-Michelin-starred restaurants. For Inside Out, which takes place inside a girl's mind, the team studied psychology and neuroscience. "From the research you get ideas for stories and characters and plot points and details."

For The Good Dinosaur, that meant going out into the wild. Sharon Calahan, who had joined the film as director of photography during the reboot, knew just the place: as a landscape artist in her spare time, she often spent weekends painting the mountains of the American north-west -- particularly Montana and Wyoming's Grand Teton National Park.

"We kept saying, 'Let's go get lost'," says producer Denise Ream. "We wanted to know what it would be like to experience what happens to our character." Sohn, Ream and the crew spent days in Grand Teton National Park, including rafting down the Snake River to research the film's river sequence. They also visited a cattle ranch; the experience, a first time for many of the crew, inspired the addition of a family of Tyrannosaurus rexes to the script.

Out in the wilderness, Sohn was struck by the beauty and danger of nature. "The river guides were very knowledgeable about survival. They would go, 'Look at that, a landslide happened down here.' We were looking at something so beautiful, but there was something really dangerous going on. We started to see that nature itself was more than just the background. It became a character in the story." In the Art Room, the walls are covered in concept art for the film, alongside dozens of photos from the research trip; scrub, trees, waterfalls, rock formations, all chronicled in minute detail.

The setting also created one of The Good Dinosaur's biggest challenges. For the look of the film, the crew had been inspired by nature documentaries and movies such as Carroll Ballard's Black Stallion (1979) and Never Cry Wolf (1983). "A nature movie has never been done in computer animation, mostly because going out into nature is one of the most challenging things to do technically," Lasseter says.

To make the natural setting feel lush and dangerous, the studio decided on an ultra-realistic style. "We wanted to make it feel like it was photographed," Lasseter says. "Actually, I believe that his word of advice was: 'I don't want it looking photoreal, I want it looking better than real,'" laughs Calahan.

Pixar has always pushed the boundaries of what's possible. Before it was an animation studio, Pixar was a tech company, spun out of LucasFilm's computer-graphics group back in 1986 and bought by Steve Jobs as a computer-hardware business.

It wasn't until the hardware business failed that it embraced its film-making talent. Ever since Toy Story, the first film entirely animated on a computer, each title has surpassed the previous technically. But The Good Dinosaur's vast wilderness setting -- combined with an accelerated production schedule -- presented the animation department with its most difficult challenge yet. "That feeling of vastness in the film, that's not something we had done before, nor is it very easy to do on computer," says Calahan. Rendering enormous landscapes presents a massive computational challenge. Typically, animated films use set extension: the main portion of a scene is animated in 3D, whereas the distance -- the sky, say -- is a flat painted image. For The Good Dinosaur, Sohn and Calahan wanted to include a number of sweeping helicopter shots, which meant rendering the entire landscape in 3D.

The team sourced topographical data of the Grand Teton National Park from the US Geological Survey. Using the relief data, they replicated 260 square kilometres of the landscape, and used programmatic generation to populate it with wildlife.

"We used it like a live-action film would; we could go out and scout locationss to find shots," Calahan says. The animation department then tweaked the landscape and wildlife as needed.

The result: The Good Dinosaur is the most visually stunning Pixar film yet. Among its other technological breakthroughs: advances in volumetric clouds, which filter and scatter light like the real thing, and water and dust effects. "When I looked at the footage, it took my breath away," Lasseter says.

The new pitch for The Good Dinosaur approved, the next step in every Pixar film is story reels: a rough cut of the film, using sketches and temporary voices, so the film-makers can watch the film as it's made. During this process, every scene -- from the dialogue down to the tiniest character expression -- will typically go through thousands of iterations. Every line of dialogue and strand of hair are refined and perfected again and again.

At the heart of Pixar is the Braintrust, a rolling group of the studio's best creative minds which helps guide every film during development. The group's members change, but it grew out of the core team who worked on Toy Story and now make up Pixar's most acclaimed directors: Lasseter, Andrew Stanton (director of Finding Nemo and Wall•E), Pete Docter (Monsters Inc, Up, Inside Out) and Lee Unkrich (Toy Story 3). (Joe Ranft, a founding member who directed Cars, died in 2005.) "The Braintrust isn't a particular set of people. It's what we call the group that gets together to address a problem," Catmull says. It meets every 12 weeks; meetings start with a screening of the most recent cut of a film. After lunch, the Braintrust provides notes on what works, and what could be improved.

"The key thing is: no mandatory notes," says Lasseter. That foundation -- the fundamental principle of candid, constructive feedback -- goes back to Lasseter's early experiences with Disney "when it was still an executive-driven studio", where animators were given mandatory notes by high-ups. "My note doesn't carry any more weight than an animator's. No one has individual ownership of an idea, because someone will spark something and you build upon it -- so then, at the end, what you have is this feeling that everybody has shared ownership, 
and being proud of the whole thing."

It's easy to talk about removing authority in theory. But for Sohn, a first-time director, pitching to a room full of Oscar-winners wasn't easy. "The speed we had to work, we were showing stuff that was really rough. We would never usually show this early," Sohn says. "But all these directors have so much experience, they know exactly what your intent is. So you can be vulnerable in front of them. You might show something that they might say, 'That's a great idea', or 'You know what? That's not as clear as you think.' But then they would offer up other ideas, or experience. Andrew might say, 'We have gone down that route before on Finding Nemo.' It would always be, 'This is something to try.'"

Lasseter and Catmull also now have less time at Pixar, spending two days a week at Disney Animation over in Burbank. As chief creative officer, Lasseter doesn't just oversee films, but provides input over almost everything that Disney does, from toys down to the company's theme-park division. "John time" is a precious commodity. What's more, he recently announced that he will be returning to co-direct a fourth Toy Story.

That announcement points to another abiding concern: at D23 Expo, the studio teased a number of sequels, including Toy Story, Finding Dory, The Incredibles II and a third Cars, but only one new original film, Coco, about the Mexican Day of the Dead. (Those fears may yet be unfounded. At Pixar, there were hints at originals in the pipeline; there are always several in development.) "Roughly, we try to have two original films to each sequel," says Catmull. "Sequels are financially less risky. But if that's all we did, we would become creatively bankrupt. Up, Ratatouille, the trash compactor that falls in love - these are high-risk ideas. So in order to take the high risks, which is very important to us, then we do things which are lower risk. We have to make sure we're also smart as a business."

For Catmull, the more pressing concern -- the one that occupies him most days -- is working out how to ensure the culture which has led to Pixar's success survives as the industry changes and staff come and go. Just like Walt Disney, Catmull and Lasseter will one day retire, and Pixar must live on. "What you don't want are people trying to repeat what we did to begin with, because we can't," Catmull says. "Instead, it's a mindset: that everyone here owns the films we're working on. Our whole history has been about changing and adapting. If the idea we had isn't working, we'll change at every level, whether it's management, production or the technical side."

To Lasseter, making The Good Dinosaur has re-energised Pixar, and doubled down its commitment to telling great stories. "It was hard for the studio, but it wants to makegreat films," he says.

"We have this simple philosophy that quality is the best business plan." Of course, there's always an outside chance that, despite all their hard work, The Good Dinosaur will fail, and Pixar's run will come to an end. "Nobody wants to be the one to break the streak," says Ream. "Luckily, I work with a ton of people who will go the extra mile to make the film better." It's a quiet moment, at the end of a long day; the WIRED photo shoot is finished, but Sohn and Ream are going back to work on the film, which is still only 50 per cent rendered. There's plenty to do before release. "My thing, at the end of the day, is I look at it like: 'Is this the best we can do?" says Ream. "And I think every single person here, would say: 'Yes'."

Oliver Franklin-Wallis is assistant editor at WIRED*, and edits the Play sectionhttps://www.wired.co.uk/topic/play.*

This article was first published in the December 2015 issue of WIRED magazine. Be the first to read WIRED's articles in print before they're posted online, and get your hands on loads of additional content by subscribing online.

This article was originally published by WIRED UK