To create a dreamy campaign for Cirque du Soleil’s new Las Vegas show, Diesel in Montreal spent a year and a half with the French Canadian troupe helping to develop the production, as well as the name, Kà. (An Egyptian term for “spirit.”) “Usually when you work with a regular consumer advertiser, you have an existing product,” says creative director Philippe Meunier. “Here, we helped create the name of the packaging and designed the packaging, then designed the campaign.” In addition to its efforts on the show’s name, the agency also made sure everything from the box office to the Web site and all the show’s imagery had a consistent look. An animated TV commercial, which broke in spot markets last week, conveys the “emotion” of the show, says Meunier, incorporating up-and-down roller-coaster-like movement. Previews for Kà began Friday; the show opens to the public in February.