Houston's version of Comic-Con gets underway Friday as Trekkies, vampires and zombies flock to downtown's George R. Brown Convention Center for the city's annual Comicpalooza.

Patrick Stewart of “Star Trek: The Next Generation” and “X-Men” fame, Michelle Rodriguez of “Resident Evil” and “Machete” star Danny Trejo are among the scheduled guests.

Filmmaker Vlad Yudin says what some consider a 'nerdy' hobby, is really big business.  Like in other markets, he says the Houston show is growing each year.  The line at a show in suburban Detroit last week wrapped around the corner.

The more famous Comic-Con International: San Diego already is sold out this year.

“A lot of shows come out, a lot of films come out in theaters and later we find out they were based on some kind of graphic novel or comic book,” Yudin tells KTRH News.

AMC's “The Walking Dead” and HBO's “Game of Thrones” are just two examples.

Yudin says what's hot right now is story lines with some sort of historical element added to it.

“You have 'Game of Thrones' which is dominating right now, there's also a 'Game of Thrones' graphic novel as well,” he says.  “You have films of course like 'Abraham Lincoln: Vampire Hunter,' so there is a lot historic stuff that's pretty cool.”

Yudin is pitching his own graphic novel “Head Smash” due out this summer.