Stop and smell ‘Spy Kids 4’

Moviegoers, at least in the United States, are showing a waning interest in 3-D. So Hollywood is looking to solve the problem as only it can: by adding a new dimension.

This time, it’s not your sight but your smell that’s being brought into the equation: “Spy Kids: All the Time in the World in 4D” director Robert Rodriguez is promising to throw audiences “nose first into the fourth dimension” this weekend when the latest installment in his family-friendly series debuts with “Aroma-Scope,” a scratch-and-sniff experience.

Rodriguez said he was inspired to add scent to his new movie after catching a whiff of the diaper of star Jessica Alba’s baby. Which should serve as a warning that not all of the odors in “Aroma-Scope” are of the sweet sort.

The director, who comes from a family of 10 kids and has five children ages 5 to 15, says he thought the low-tech “Aroma-Scope” would be popular with his young fan base, and a way to make the movie more interactive. And parents will be happy to know that it’s not going to cost a dime extra on top of the 3-D.

So how does it work? When you enter the theater and collect your 3-D glasses, you also get a postcard embedded with 8 squares that are numbered. When a digit flashes on screen, it’s time to scratch the square with that number and inhale.

At the film’s premiere a few weeks ago at L.A. Live, youngsters in the audience seemed excited by the prospect, though squinting at a card in a dark theater didn’t always make for the most seamless experience. (When the first number flashed on screen, choruses of “I can’t see!” erupted in the balcony.)

Rodriguez said he started the process by sniffing a menu of smells from a company that specializes in printing scents for magazines and other publications, then decided which ones he wanted to work into the film.

He said unlike previous experiments with piping scents into theaters, his “Aroma-Scope” cards offer viewers control.

“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.”

Crazy enough to work?

Is Robert Rodriguez on to something with “Aroma-Scope”? There are plenty of other recent movies that could benefit from a little olfactory bonus. Here are a few that come to mind:

“The Tree of Life.” Sure Terrence Malick’s movie contemplates the meaning of life, God, earthly existence, all of that. But it could take Aroma-scope to truly elevate the moviegoing experience. Without it, can you really sense the cut grass, the seashore, the DDT or, for that matter, the dinosaur?

“Bridesmaids.” There isn’t a moviegoer out there who didn’t cringe a little bit when Kristen Wiig and her friends began defecating in the bridal-gown shop. But did watching it offer enough of a visceral kick? A strategically deployed scratch-and-sniff card would certainly do the trick.

“Pirates of the Caribbean: On Stranger Tides.” Some would say this fourquel already ran the risk of giving us sensory overload. But there are so many great pirate smells that could help plunge us into that world. There’s rum, for instance, or the tip of a recently deployed sword blade, or even the wafting odors of the Fountain of Youth. Most of all, there’s Keith Richards.

“Larry Crowne.” Tom Hanks demonstrates how to make French toast in Julia Roberts’ college class. But the true smell associated with this schmaltzy film, based on the overwhelmingly negative reviews, should probably be cheese. May we suggest Limburger?

A brief history of theater odors

The idea of enhancing the film-going experience with scent goes back more than 50 years. In 1959, a movie called “Behind the Great Wall,” a China travelogue, featured “AromaRama,” with odors pumped into a theater in New York; among the smells were grass, earth, exploding firecrackers, a river, incense, burning torches and horses.

Writing in the New York Times, reviewer Bosley Crowther opined that the odors were “mostly elusive, oppressive or perfunctory and banal.”

“During a hurried tour of Hong Kong, there emerges a sort of spicy smell,” he said. “A tarrish or oily odor comes with a scene on the water-front. A light fragrance somewhat suggesting wet straw emerges in the scenes of the cormorant fishing, and the sequence of the tiger hunt is accompanied by an odor that struck this viewer as that of banana oil. Several times there’s a smell of smoke or incense, and the scenes of the parade with the flowers are rendered almost distressing by a vaporized squirt of cheap perfume.”

A competing system, Smell-O-Vision, debuted in 1960 with the B-movie “Scent of Mystery.”

Smells at the movies made a brief comeback in 1981 with John Waters’ comedy “Polyester.” His scratch-and-stiff card gimmick, similar to Rodriguez’s “Aroma-Scope” was called “Odorama.” It featured the scents of flowers, pizza, glue, gas, grass and feces. It was advertised with the slogan, “It’ll blow your nose!”

julie.makinen@latimes.com

steve.zeitchik@latimes.com