It’s one thing to release a pic midweek to build positive word-of-mouth. It’s another for that same pic to launch early to generate goodwill mostly for the format in which it’s being presented.But that’s exactly what Paramount is doing with “Transformers: Dark of the Moon,” which opens at 9 tonight at 2,789 3D locations, including 146 Imax runs. Par’s 3D-only bow of “Transformers” — an industry first, according to the studio — comes one day before the film’s nationwide release at 4,011 locations in both formats. Though today’s tallies won’t figure into weekend totals, it will be the film’s first gauge of interest. More importantly, however, the pic’s exclusive 3D kick-start signifies an effort by Par to build positive buzz for the format, which has been losing marketshare in recent months. “We’re very cognizant of the fact that we need to earn back the trust of the fans,” said Par vice chairman Rob Moore, referring to the declining 3D market. Par has actively promoted “Transformers” as a 3D event, structuring some of its TV spots to highlight the multi-dimensions. Warners also has been working to up “Harry Potter and the Deathly Hallows: Part 2′s” profile in 3D (the pic’s trailer says, “Complete the journey in 3D”). Both pics are expected to appeal to a broader aud than some recent fanboy titles. “Our goal is to get the word out because ultimately there’s nothing that we can do on TV to show people how good the 3D really is,” he said.