'Spy Kids: All the Time in the World': 4D Element Explained

The Weinstein Company

Director Robert Rodriguez aims to propel each moviegoer's "nose into the fourth dimension." Here's how it works.

Spy Kids: All the Time in the World is upping the ante when it comes to multiple dimensions.

Robert Rodriguez's fourth installment in his Spy Kids franchise, which stars Jessica Alba and Jeremy Piven, hits theaters Friday, where it will be available in 4D.

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So what exactly can moviegoers expect from the added dimension?

The experience actually will feature "Aroma-Scope," a sort of scratch-and-sniff feature that allows audiences to not only watch but also smell along with the movie.

What happens is, moviegoers will get a postcard that includes eight numbered squares, according to the Los Angeles Times. When a number pops up on the screen, viewers will know to scratch that particular square, releasing a scent.

STORY: 'Spy Kids 4: All the Time in the World' Smells Like Trouble With Aroma-Scope

The feature will propel each moviegoer's "nose first into the fourth dimension," Rodriguez said.

But let the scratch-and-sniffer beware: The director said he came up with the idea to add the feature to the latest Spy Kids after inhaling the smell of Alba's baby's diaper.

But, he added, the audience has the ultimate control over whether they want to inhale whatever scent awaits.

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"The nice thing about cards is, if you don't want to smell you don't have to," he said. "You're doing it by your own willpower."

Additionally, the extra feature isn't adding anything to the ticket price above the 3D.