Disney’s “Tron,” the granddaddy of CGI animated films, celebrates its 35th anniversary on July 9. And over the decades, the sci-fi adventure has spawned video games, the 2010 movie sequel “Tron: Legacy,” a high-tech ride at Shanghai Disney, an animated series, and even talk of a possible third sequel with Oscar winner Jared Leto in early talks to star.

And “Tron” has influenced CGI animators worldwide. In fact, Disney/Pixar’s John Lasseter has acknowledged that “Without ‘Tron,’ there would be no ‘Toy Story.’”

But back in 1982, not only did “Tron” receive mixed reviews from critics and audiences, Hollywood didn’t welcome the film, which paid homage to “The Wizard of Oz” and “Metropolis,” with open arms.

“It certainly wasn’t the reaction we expected,” said Steven Lisberger, who wrote and directed the film starring Jeff Bridges as computer games creator who finds himself zapped inside a power hungry Master Control program after he hacks into the mainframe computer of his ruthlessly ambitious ex-employer (David Warner). Once inside the computer, he joins up with computer gladiators as he tries to fight his way back to the real world.

“I say the lesson that one learns is that you pay the price for going against the status quo,” he admitted. “It’s difficult to emphasize enough how terrified of computers and technology people were, and Hollywood in particular. The threat that ‘Tron’ represented was that somehow computers were going to get involved with movie making and that they were going to get involved with our lives.”

And Hollywood was shocked it was Disney that was “suggesting” that computers were going to be part of everyone’s lives. “When I think about Disney, I always think about how they provide nostalgia and a certain amount of comfort that comes from nostalgia. It’s interesting to see how over the decades ‘Tron’ has now gained a patina of nostalgia. In that sense it’s become more of a Disney film now then it was back then. It was very upsetting to people that Disney crossed the line and did something for which there was no precedent.”

Lisberger and his producing partner Donald Kushner, who is now co-owner of the TCL Chinese Theatres, moved from Boston to Venice in the mid-70s and began working on “Animalympics,” two animated NBC specials that were to air during the Winter and Summer Olympics in 1980. Only the winter one aired because the U.S. boycotted the Summer Olympics in Moscow to protest the USSR’s invasion of Afghanistan.

It was during the production that the idea for “Tron” took shape.

“We were playing video games,” noted Bill Kroyer, who was an animator on “Animalympics.” “And that’s when he first started pitching the idea to us about a guy who gets lost in a video game. We thought that was an original idea, so as we were wrapping up ‘Animalympics,’ we were boarding and developing ‘Tron.’”

The award-winning Kroyer, who was computer image choreographer on “Tron” and is now professor and head of the digital animation program at Chapman University, noted that “nothing we needed existed” to make the movie. “We didn’t come up with the movie to exploit existing technology. We came up with the movie and then we said, ‘We believe we can make the technology as we make the movie.’ It’s that metaphor literally of successful people who jump off the cliff and build their wings on the way down.”

Initially, Lisberger and Kushner tried to make “Tron” as an independent production. “I put every cent I had in the world in the development in the movie,” said Lisberger. “We had everything but production money.”

“We got a couple of studios interested, one of which was Disney, that was interested,” said Kushner, who noted that “a lot of studios turned us down.”

But not Disney.

At that time, Disney wasn’t the powerhouse as it is today. There was little animation and its live-action films, including “Hot Lead and Cold Feet” and “Condorman,” didn’t set the box office on fire.

“People aren’t aware today what Disney Studios was like at that time,” said Lisberger. “It was a sleepy, forgotten studio.”

Kroyer knew all too well how sleepy it was. “When I started at Disney I was in a 2D animation training program with the Nine Old Men. My roommates were John Musker, Brad Bird, and Henry Selick. We all started in the same room training together with pencils, flipping paper. I often tell the story that my desk and my work process had not changed in 40 years.”

Lisberger acknowledged he owes a lot to Tom Wilhite, the studio’s young production head.

Disney, said Kroyer, was “desperate for something to happen. I don’t know how [Wilhite] talked his way in, but he was a young executive who really desperately wanted to try something new. So this was right up his alley. He’s the one who really stuck his neck out and said ‘We should do this movie ‘Tron.’’ And the irony is that Disney is the only film studio that could have made it because essentially ‘Tron’ is an animated film.”

Besides Disney, Bridges was also willing to take a chance on the film.

“It had never been done before,” he noted. “I was intrigued just because of that. Steven Lisberger is the fella who came up with it. It was his first film and I’ve had wonderful success with first-time directors. They don’t know what they can’t do, so they just let their imagination go.”

Still, said Kushner, “there was like an us versus them mentality” between the “Tron” animators and the veterans on the lot.

“Most of the people there didn’t really he a clue what we were doing,” Kroyer said. “Disney at the time, remember, had the terror of not doing anything Walt hadn’t done. They used to say, ‘We do what we do best,’ which was a cover-up for saying ‘we don’t want to do anything we haven’t already done.’”

Visual effects supervisor Harrison Ellenshaw, a renowned matte painter who had earned an Oscar nomination with his father Peter Ellenshaw for the special effects on Disney’s 1979 “The Black Hole,” had also worked on 1977’s “Star Wars” and 1980’s “The Empire Strikes Back.” He also has an associate producer credit on “Tron” for being the go between the “Tron” crew and the old guard at Disney.

“I was trustworthy,” he said. “When they idea of ‘Tron’ came along, they said, ‘we are going to greenlight it and Harrison can kind of be our insurance. He’ll make sure that these guys are legit and and aren’t going to completely rip us off.”

Kroyer described working on “Tron” as “Christmas morning every day” because they would wake up and there would be some new digital invention. “The momentum was there,” he said. “During the course of the production it was changed radically. That this excitement of being able to be out in the frontier of something brand new is something that didn’t happen all the time. That’s why we were so excited to do it every day.”

“I will tell you that we were energizing ourselves,” noted Lisberger. “We had this gut feeling because all of us had some experience with these techniques in small amounts. We had a feeling that if we set this up correctly and had the right team team of people, that we could turn this into a process that would be able to handle this quantity. And we did it, but while it was happening, it was intermittently terrifying but at the same time … it was very exhilarating.”

There are 15 to 20 minutes of solid computer animation in the film, said Lisberger, with “computer animation sprinkled” throughout. Four companies provided the digital animation with each doing a couple of minutes.

“It’s inconceivable now for people to think how we actually did the CG,” Lisberger said. “There was no movement. Computers could only generate individual frames. There was no way to digitally put them on film so you actually set up a motion picture camera in front of a computer screen and you filmed it frame by frame. Some of the frames took hours to generate.”

“Tron,” which was shot on 70mm, also used backlit animation in which actors wearing white would be shot in black and white against a black screen which gives the computer gladiators the look of silent film performers.

“Great credit has to go to Jeff, Bruce Boxleitner, Cindy Morgan, and David Warner,” said Ellenshaw. “I’d be on the set and nobody complained, saying ‘I’m really tired. I’m in this uncomfortable costume and look stupid. I’m wearing a hockey helmet and I have to act against something and I don’t know what’s there.”

Bridges recalled laughing the pain he felt wearing a dance belt, which is a form of jock strap; “sitting down … that’s etched in my memory and other places unfortunately.”

As the production continued, said Kroyer, more and more animators came over to see what was going on and watch them work. “Of course the most famous is John Lasseter, who became obsessed with us. He used to come and sit behind me all the time and watch. That’s where he really started to get hooked on computer animation.”

“Tron,” which came out the summer of such visual effects-heavy films as “E.T.,” “Poltergeist,” “Blade Runner,” and “Star Trek II: The Wrath of Khan,” failed to receive an Oscar nomination for special effects, though it was nominated for costume design and sound.

“I am a member of the Academy, so I was there when the process took place on the committee of which films should get nominations,” said Ellenshaw. “Let’s say I was disappointed. They didn’t understand it. They weren’t comfortable with it. They begrudged the fact that it looked so unique. Sometimes you can’t do too much out of the comfort zone.”

The film grossed $33 million, placing 22nd on the 1982 box office chart, better than Ridley Scott’s “Blade Runner” and George Miller’s “The Road Warrior,” but $300 million-plus less than the No. 1 film of the year, “E.T.”

Kusher lamented that though “Tron” was scheduled to be on both the cover of Time and Newsweek, both magazines pulled it at the last minute. “It was some political event that happened,” he said. “As they went to press they switched the stories and took ‘Tron’ off the cover.”

Lisberger recalled having a conversation with Scott at Bridges’ house. “It was like that scene in ‘Jaws’ where comparing scars. He was saying how terribly beaten up he was regarding the office on ‘Blade Runner’ and I showed him my scars from ‘Tron.’ The thing that was in the air was that it wasn’t enough that the film did business or that they even paid for themselves. What happened was ‘E.T.’ came out and it raised the bar” at the box office and anything less was seen as a disappointment.

Lisberger finally experienced the tremendous impact of “Tron” 15 years ago at a screening he was invited to by Roger Ebert at the University of Illinois at Urbana.

“They had an old theater there that seated 1,800 people,” he said. “And so I was shocked because the 1,800 seats sold out. It was all these people that were studying computers. It’s very satisfying for people to say ‘I got into film because of you. I got into computer animation. I got into computers because of you. I am a software engineer because of you.’”

“Tron,” said Lisberger, is “so idealistic. It was the digital frontier and we were seeing it and exploring it for the first time. We were very, very idealistic and you can feel that when you watch ‘Tron.’”