Pixar: Small wonders

The scene in cinemas where Toy Story 3 opens later this month will be familiar to everyone who has ventured out to watch a Pixar film during the 16 years they've been in existence. First, lights will fall. Then, trailers will be screened, along with that awful advert telling punters to shut up and switch off their phones. Finally, after a brief silence and the odd "ssh!" projectors will whirr for the main event.

At which point, in corners of every Toy Story auditorium, you'll hear a murmur of confusion: the film being shown will very much not be the latest blockbusting adventures of Buzz Lightyear and friends. Instead, viewers will spend the next six minutes watching a bizarre-looking yarn, part hand-drawn cartoon, part cheery CG animation, set to music. It is called Day & Night, and it is this year's Pixar short.

The short – a film lasting roughly five minutes, screened immediately before a feature – is part of a tradition stretching back to the early days of Hollywood (vintage Disney films always had them), which fell into abeyance some time in the late 1970s, but in recent years has experienced a revival at the hands of Pixar: the studio has made them for every movie it has ever released, with the exception of 1994's Toy Story.

At their best, which is how Pixar does them, shorts are a sort of artistic riff: a chance for animators to play with new technology, effects, or storytelling techniques, while giving viewers a tasty hors-d'oeuvre. As such, they can be important art form. Not for nothing is there a category for Best Animated Short at the Oscars. Since the late 1980s, Pixar has been nominated for it nine times, with three victories.

Classic shorts, just like good literary short-stories, usually have a twist. Day & Night, for example, involves two hand-drawn, Looney Tunes-style figures, whose bodies double up as keyholes through which we see a selection of 3D landscapes. Depending on which character's body you're looking through, the scene is depicted in either bright sunlight or after dark.

The result is a cunning little vignette: part a musing on the circular nature of nature, part an exploration of emotional and visual contrasts, and the old adage that opposites attract. On a technical level, it also cutely demonstrates that computer-generated animation and old-fashioned hand-drawn cartoons don't have to be mutually-exclusive art forms. In the weeks since Toy Story 3 opened in the US, it has been hoovering up critical plaudits.

At Pixar, they've been playing with these kinds of film for more than 25 years now. And their back catalogue provides a potted history of the studio that developed and then popularised computer-generated animation. Even the firm's logo, an animated desk lamp, was taken from a short – the 1986 title Luxo Jr. A vast scale model of the lamp can be found outside its headquarters, across the bay from San Francisco.

Watch the greatest Pixar shorts (a selection are profiled on these pages, and are well worth tracking down on YouTube) and you will witness not just brilliant storytelling, but agenda-setting advances in film-making. The earliest feel almost like museum pieces: the first animated stories to have been created not by humans with pens and ink, but on a computer.

The first ever one was called The Adventures of André and Wally B. It was made in 1984 when Pixar was a technology division of George Lucas's business empire, with a remit to develop machines and software that could be sold or licensed to film-makers looking to use them to create animation. The film's role wasn't so much to tell an entertaining story as to demonstrate to viewers that the computers that the Silicon Valley firm hoped to sell could really worked.

The story, which lasts just a couple of minutes, follows a bumblebee chasing a sort of cartoon gromit through a forest. Today, its animation looks primitive. Characters are made from 3D geometric shapes. They move jerkily. But when the film was first shown in public, at that year's Siggraph (an annual convention for the graphics industry) it was so revolutionary that it brought the house down. No one had previously thought that CG animation would really work.

In the years that followed, Pixar's shorts got tighter, and sharper, and more entertaining. Luxo Jr won an Oscar nomination. In 1987, Red's Dream, a sort of film noir about a monocycle, showed that CGI could do special effects – in this case rain – that were far more lifelike than any hand-drawn cartoon had ever achieved. Tin Toy, which won Pixar's first Academy Award, contained its first CGI human being, a baby.

In the mid 1980s, George Lucas sold Pixar to Steve Jobs. A few years later, the Apple founder decided to turn it into a working film studio, meaning that the role of the shorts changed: they became part of the product: a symbol of the studio's creative ambition, rather than a tool for simply selling technology, and a means to develop artistic flourishes that would be used later, in full-blown feature films.

"In a short, you are free to experiment," says Teddy Newton, who directed Day & Night. "We've always used them to develop characters or technology that you see cropping up down the line. My idea, which I think is what helped the film to get green-lit, was that I also wanted to experiment with the whole idea of a story, and what a story is."

Experiments taht work in a shorter movie usually become part of the creative palette that Pixar uses in a longer film. The telegraph wire in For the Birds, for example, was repurposed several years later for the blockbuster Cars. The talking clouds in Partly Cloudy, which took months of painstaking development to render sufficiently softly, can also be seen in UP. Most importantly of all, the film that turned Pixar into a commercial phenomenon, 1995's Toy Story, would never had been made were it not for the success of Tin Toy.

These days, Pixar is part of the Disney empire, with hundreds of employees churning out a film a year. And the short is also used to develop the creative talent of tomorrow. Young animators or designers who are perhaps too green to take on an entire feature (which involves four solid years of work) are allowed a smaller, cheaper, and freer forum to showcase their abilities.

"If features are symphonies then shorts are minuets," says Kevin Reher, who produced Day & Night. "They give a variety of people an opportunity to do something that they wouldn't otherwise do. Teddy's always been one of the most creative guys around here, and this has given him a chance to show the world his wonderful ideas. It's one of the main reasons we have them."

The other reason, bluntly, is that the public adores them. "You'd be surprised how many people love the fact we do them. I get that all the time. It's important. Other studios don't really do them, because they're expensive. They cost a smaller version of what a feature costs and they don't really make money. But for us, they are part of the brand. And the talent they develop can be priceless."

In today's Hollywood, that's refreshing talk. We live, after all, in an era of "sequel-itis," when major studios are continually maligned for churning out unoriginal stodge. But Pixar's shorts remain islands of proud originality. While both Toy Story 3 and its 2011 feature, Cars 2, return to trusty old concepts. The inventive little flicks that will precede them in cinemas successfully demonstrate that the firm can still foster creativity – and that small really is beautiful.

'Toy Story 3' opens nationwide on 19 July

For further reading: 'The Pixar Touch: the Making of a Company' by David A Price (Vintage). Order for £11 from the Independent Bookshop: 08430 600 030

Brief encounters: six of PIXAR's best

Luxo Jr (1986)

The film that brought Pixar mainstream attention, and became the first Oscar-nominated computer animation, involved two desk lamps playing with a ball. It was the simplest of ideas, but the genius was in the execution: even though they lacked faces, the vibrant personalities of the lamps are expertly demonstrated through movement.

Tin Toy (1988)

Here we see a wind-up toy being terrorised by a destructive toddler. Not only did this hilarious narrative win Pixar its first Oscar, it also showed the studio for the first time rendering a human in CG animation. Most importantly of all, in its depiction of sentient toys and their vandalistic young owners, the film set the stage for 'Toy Story'.

Knick Knack (1989)

A dark but hilariously wicked skit about a snowman trying to break out of his globe, and make friends with a pneumatic female desk ornament. As ever, with Pixar's earlier films, the animation marked a technological leap, in this case with the flawless rendering of hundreds of snowflakes. In a little known piece of late editing, the female star's breasts were reduced in size to make the film palatable for a family audience.

For the Birds (2000)

A large but dopey bird wants to fit in with his smaller avian siblings who sit on a power cable. Depicting feathers was a tough task for animators, and their groundbreaking success in this film was built on by the creators of the hit 'Monsters Inc', who won plaudits for the fluffy coats of their principal characters.

Boundin' (2003)

A musical ditty about sheep shearing set in Montana, which stars a longhorn sheep who is embarrassed by the annual ritual of being shorn. Boundin' is subtly different to many Pixar shorts in that it tells an old-fashioned morality tale. As such, its success demonstrates the firm's mastery of traditional as well as agenda-setting storytelling techniques.

Partly Cloudy (2009)

Storks and talking clouds collaborate to make, puppies, babies and other cuddly young creatures which are distributed on suburban doorsteps. The hero of the piece is a rain cloud called Gus, who has problems creating cuddly creatures, and instead churns out crocodiles and electric eels and other violent animals. Joyful.