SAN DIEGO — A population the size of a city has descended on downtown San Diego this week to celebrate popular culture at a scale that difficult to understand unless you experience it. The mammoth San Diego Convention Center is bulging from the more than 140,000 unique visitors visiting the event that started Thursday and lasts through the weekend.

The 40th annual San Diego Comic-Con is on. It has been sold out for months. Hotel rooms are booked and those without often petition the lucky ones for a vacant spot on the floor.

For promoters of television, movies, books, comics, video games and gadgets, it's the chance to target the taste-makers and build the elusive "buzz" that helps guarantee financial success. For fans, it's the chance to watch the stars come out — the kind that arrive in limos and bring an entourage. The biggest names in Hollywood have been here in the last decade but this year's event provides an unequaled trio of filmmakers who will be especially loved by those who embrace genre entertainment. James Cameron (Terminator 2, Aliens, Titanic), Peter Jackson (Lord of the Rings, King Kong) and Japanese legend Hayao Miyazaki (the Japanese Walt Disney) who is famous for not appearing in public, will all be on hand — Cameron and Jackson share a panel in addition to their own.

Entertainment Weekly devotes a cover and a big chunk of its interior to the goings-on and USA Today writes about it nationally, while the international press joins in as well. It impacts culture on a national scale and even with the weak economy it's full speed ahead.

Television has grown in importance as more shows have decided to peddle their good names in front of the crowds. "Lost" did this a few years to great success as did "Battlestar Gallactica." A search for events related to television at the Comic-Con program guide (www.Comic-Con.org) yields 38 different results, starting with the screening for three shows, "V," "Human Target," and "Vampire Diaries," on the opening night of the event, once reserved only for retailers. Screenings may be nice but it's having creators like Joss Whedon (Dollhouse, Firefly) show up that attracts fans in great flocks.

Authors like Orson Scott Card and Stephanie Meyer show up, too, so they can respond to their followings and participate in Q&A sessions. "Twlight" made a big splash last year and its sequel and its stars are back to woo worshipping audiences.