IT ALL began when John Lasseter's pastel drawing of a metal sprung lamp was turned into the hero of an animated short film.
The creation of Luxo Jr, 20 years ago, marked the birth of the computer animation revolution, as well as the now legendary Pixar Animation Studios the company behind Toy Story, Finding Nemo and The Incredibles.
Now, the inside story of childhood dreams brought to life in animation's biggest modern success story is being told in an exhibition that opens today at the National Museum of Scotland.
Pixar: 20 Years of Animation, sets out to show that computers don't make great films, but art and artists do. It includes early images from Pixar's new film, Ratatouille, that have never been shown outside Edinburgh.
Pixar films such as Cars or Toy Story are the modern equivalent of classics like Snow White and the Seven Dwarfs for an earlier generation, said Gordon Rintoul, the NMS director.
Just as people now show the early stills from those films, he said, the art of Pixar was on display.
The Pixar show was launched in New York and has toured to London and Tokyo. The company pioneered the use of 3-D computer models to create and move its characters, becoming internationally famous for its CGI (computer generated image) work.
But the exhibition aims to show the old-fashioned art behind that success - the paintings and drawings, stories and characters.
"Our artists work in traditional media - hand drawings, painting, sculpture, as well as the computer - to create our films," said Lasseter, a Pixar founder. "Computers don't create computer animation any more than a pencil creates pencil animation.
What creates computer animation is the artist."
In a $7 billion share deal agreed last year, Disney bought Pixar, and Lasseter became chief creative officer of Pixar and Disney Animation Studios.
The exhibition includes more than 250 concept drawings and paintings, as well as resin models.
There are storyboards, which map out the plot, "colour scripts" that outline the mood and emotion of scenes, and the "story reels" that begin to build a basic version of a film.
Lasseter's mantra is that three things make a great film: "great story, fantastic characters, and a world that can only exist in animation," said the exhibition's curator, Elyse Klaidman, dean of art at Pixar.
The exhibition varies from figures of characters Hopper and Slim from A Bug's Life, to the challenges of building the furry blue giant Sullivan in Monsters, Inc, to the blue acrylic studies of the ocean in Finding Nemo.
It features early drawings of Woody and Buzz Lightyear.
Ratatouille, the new offering, saw Pixar animators sent on a research trip in the sewers of the French capital. "It's about a rat living in Paris who dreams of being a five-star chef," said animator Warren Trezevant.
"Rats aren't really found in the kitchen so he has a challenge as to how to pursue this dream."
In the great Hollywood tradition it's billed as a universal story and a "buddy movie" as Remy the rat teams up with Linguine, a chef who can't cook.
"The origin of the idea is how do you pursue a dream that the world doesn't expect of you," said Mr Trezevant.
"A lot of people perceive Pixar to be all computers. We spend quite a lot of effort using traditional media and traditional skills."
• IT TAKES, on average, four years and 250 people to make a full-length Pixar film.
Luxo Jr was the 1986 short film by Pixar employee John Lasseter that won an Oscar nomination and saw the company shift from computers to making animated commercials.
Pixar reached a $26 million deal with Disney to produce computer-animated films. The first was Toy Story, released in 1995.
An extension of Pixar's short Tin Toy, it made $200 million in the US and earned Lasseter an Academy Award. The hits A Bug's Life, Toy Story 2, Monsters Inc, Finding Nemo and The Incredibles followed from 1998 to 2004. The Golden Globe-winning Cars was released in 2006.
There will be weekly screenings of Pixar animated films throughout the National Museum of Scotland exhibition, and a vote on a favourite.