I RAN INTO JAMES CAMERON, THE KING of the World, last week. He was convivial. His new TV show, “Dark Angel,” was bleak. I had the distinct feeling that it should have been the other way around. Cameron looks uncomfortable trying to be convivial. And his network, Fox, was hoping for an upbeat show, not another dose of post-apocalyptic gloom.Curiosity drove me to the advance screening of “Dark Angel,” which Cameron co-wrote and co-produced. It’s been almost five years since he shot “Titanic,” in which he set records for budget overages as well as box office grosses. Amid that frenzied shoot, the dour director also set an all-time record for tossing studio executives off his set. By the time he was done, the entire Fox executive corps was in therapy. Rather than try to top himself in these categories, Cameron chose an easier, more remunerative route. He decided to conquer television. How could a superstar director fail in the relatively tame world of TV? HE SHOULD HAVE DONE MORE RESEARCH. Steven Spielberg has hit a record number of speed bumps in TV: “SeaQuest DSV” sank beneath the waves. So did “High Incident,” “Amazing Stories” and “Semper Fi,” his latest caper. Other feature luminaries have flopped as well. Roland Emmerich and Dean Devlin were going to take TV by storm after “Independence Day,” but they bombed with their first series, “The Visitor.” Kevin Smith also has had a tough time in TV, as has Michael Apted and film producers like Joel Silver (remember “Action,” which had none?). There was a time when talented filmmakers were all TV-trained — remember Arthur Penn, Franklin Schaffner and Sidney Lumet? Those were the days when longform drama reigned supreme on the networks, much of it live. Story-telling skills and three-act structures were learned in TV and translated to movies. Today they just get in the way. A talent for knocking out sitcoms doesn’t help much in the feature game, and, conversely, mastery of wide-screen pyrotechnics isn’t a passport to TV success. There are exceptions, of course: Mimi Leder’s “ER” training has translated to some solid movies, for example, and Aaron Sorkin hit a home run with “West Wing” after enduring the frustrations of screenwriting. SO WILL THE KING FOLLOW SUIT? He’s certainly put his formidable ego on the line. Most new TV series unfold on the tube, but Cameron wanted a star-studded premiere (no stars showed up). Before his audience could see the show, the King delivered what sounded amazingly like an Oscar-acceptance speech, thanking his aides, his family and his cast. He even exalted in his show’s high audience awareness rating. When his show finally rolled, however, viewers couldn’t help but wonder whether awareness will translate into a weekly following. Unlike a movie, a weekly TV show has to be welcomed into your home week after week. “Dark Angel” isn’t exactly warm and cuddly. It’s set in an impoverished, nasty, garbage-strewn, tyrannical future, focusing on a sprightly nymphet who talks hip-hop and has moves like an outtake from “The Matrix.” The reason she can deck 200-pounders and dive through windows, we are told, is that she is “transgenic,” i.e., the product of a gene-splicing experiment. Her antics are entertaining, the camera angles novel and the pace aggressively comic-strippy, but there’s something oppressive about both the mood of the show and its intent. This is a show that makes “Blade Runner” seem like “Mary Poppins.” It’s blatantly aimed at that magical young demo ogled by every network chief. Indeed, its young star, Jessica Alba, is an arresting presence even though her performance is one-note and her permanent wardrobe is a skintight bodysuit. Having lured every teenage girl in the world to see “Titanic” two or three times, Cameron clearly aspires to be King of the Teens as well as of the world. He may succeed. Fox is putting a hefty promotional push behind “Dark Angel.” Time Magazine wrote about Alba: “We have seen the woman of the future and she kicks butt.” Surely the convivial King must have relished that image.