By Keily Oakes BBC News entertainment reporter

In making The Incredibles writer and director Brad Bird embarked on one of the most ambitious animation projects in history.

The Incredible family find it hard to be normal

And as seems fitting, it was with one of the most-grounding breaking and celebrated studios, Pixar.

Bird came up with the idea for The Incredibles, about a superhero who retires to become a regular guy, 12 years ago.

He is delighted with how the finished product compares to his first vision of it all those years ago, despite hundreds of people having an input it in its process.

"It's very close to the film that I set out to make," he said.

"It's this kind of process of letting things go and rebuilding that you go through, so things did change. The villain is different to the one I started out with but it's still very much the movie I set out to make."

Human focus

One of the reasons The Incredibles was one of Pixar's toughest assignments was its length. At two hours it is its longest animation to date.

But it is also the first time that humans have been the focus of the entire movie, and it is has a darker side.

Creator and director Brad Bird also voices the character of Edna Mode

Previously it had been sea creatures in Finding Nemo or insects in A Bug's Life.

But as Bird says "people know how humans move".

So it took a whole new approach and way of working in the genre to come up with the finished article, which was not always easy, but each hurdle was eventually overcome.

Bird has an extensive background in animation. As a precocious three-year-old he began drawing sequential pictures which he later realised were his first cartoons.

At the age of 11 he began on his first animation film, taking three years to create it showed how much he had grown and learned during the long process.

Learning curve

The film made its way to Disney where Bird was given a mentor.

He also worked with Steven Spielberg on an episode of his Amazing Stories series, called Family Dog.

That job led to him being hired for The Simpsons, where he spent eight seasons.

The experience of the animation process proved invaluable for his next project, The Iron Giant.

"I learned a lot from The Simpsons about the process of seeing over 160 episodes through the growth and birthing process," said Bird.

"In TV you have to move quickly and you can't linger over decisions.

"That helped me enormously when it came to The Iron Giant because we had half the time and a third of the money of other animated features and we still had big ambitions and I think the fact of having to make decisions quickly helped."

He added: "The Iron Giant then helped me make The Incredibles because we were trying to make a larger film than we had time or money for."

But Bird's talents extend even further than directing.

He actually voices one of the characters, the fashion designer/scientist Edna Mode, although that was not the original plan.

"We do temporary voices when we prepare movies, just as we use storyboards and soundtracks, with no intent to use them but just to get a sense of the movie.

Bird directed The Iron Giant for the big screen

"Pixar is large enough that you can cast around and find enough characters for the film. So we did that with the intent of replacing them with more qualified people.

"But every once in a while people like the voices that are in the temporary track. It was not the intention for me to do the voice, but it just stayed in there."

'Case closed'

Although Bird has largely worked in animation throughout his career, he does not want to limit himself to the genre and would like to try live action movies, perhaps mixed with animation.

But despite revelling in the superhero story of The Incredibles he cannot see himself ever taking on James Bond.

"If I could go back in time and have Sean Connery in the mid '60s I would do it in a shot. But for me he's Bond - case closed."

Bird does not know if there will be a sequel to The Incredibles.

He joked: "I just try to make a satisfying ending, and every time you do a satisfying ending they say, 'You're setting up a sequel.'"