If you’ve been through Pirates of the Caribbean at Disneyland since the 2006 Dead Man’s Chest re-fit, you probably recall the giant ghostly image of “Davy Jones” floating on what appears to be a waterfall in the ride’s Grotto area. Riders pass through the illusion without actually getting wet.
This “fog screen” tech works by directing a fine aerosol — often water for safety, cost, and convenience— through special laminar-flow nozzles to create a smooth (non-turbulent) curtain of rising fog. In water-based systems, the particles are commonly generated ultrasonically, like the mist that comes out of an ultrasonic humidifier. Still or moving images are front- or rear-projected onto this intangible screen, reflecting off the tiny airborne particles to create a beautiful, eerie “hologram” effect.
Established commercial makers of fog screen hardware include FogScreen, IO2 Technology, and the regrettably-anglicized Russian Displair. The systems tend to be priced for rental, professional, and specialized/niche use (i.e. you have to ask how much, because they want to break it to you gently), and the interactive version is much less common than the static “dumb” type. If you want to play with a “smart” fog screen yourself, you’ll have to pay through the nose, build your own, or show up at an event that has one on display.
On that note, northern California readers may be interested to learn that AerScreen will be on-site at the upcoming Bay Area Maker Faire 2014, showing off at least one interactive fog screen prototype. Personally, I’ll be curious to see how they implement the gestural interface, and to get a close look at the laminar-flow plumbing. If you’re interested in fog screens and you’re going to be in town the weekend of May 17, don’t miss the chance to come check it out.