SAN DIEGO (Reuters) - The stars of "Twilight" gathered for the final time at the Comic-Con pop culture convention on Thursday, laughing and joking with fans as they reflected on a "bittersweet" end to the film franchise that catapulted them to fame.

The "Twilight" films - five in all based on a series of young adult novels by author Stephenie Meyer about a vampire, Edward Cullen, who falls in love with a human girl, Bella Swan - have become a blockbuster franchise earning $2.5 billion at global box offices from the first four films.

The final installment, "The Twilight Saga: Breaking Dawn - Part 2" is due in theaters in November.

"If you told me tomorrow that we had to reshoot some scene, I'd be so happy because I do enjoy living in this world. We got to do it for four years and I put everything I had into it," Kristen Stewart, who plays Swan, told reporters at Comic-Con.

"Even though it's a bummer to walk away, it's something I'll always have."

She was joined by fellow actors Robert Pattinson, Taylor Lautner, author Meyer and newcomer Mackenzie Foy, who plays Edward and Bella's daughter, Renesmee.

Comic-Con attracts more than 125,000 movie, TV, comic book and pop culture fans annually, and Hollywood's studios turn out with upcoming films and stars to promote. The "Twilight" makers used the convention as a launching pad for the first film in 2008 and they continue to return to reach hard-core followers.

Thousands of fans lined up for hours - and for some people, days - to get into a Comic-Con panel where the stars talked about the film and treated fans to the first seven minutes of "Breaking Dawn - Part 2."

In the clip, Bella is seen experiencing her first moments as a vampire, reuniting with husband Edward and coming to terms with her newfound bloodlust. The footage ended just as Bella meets Renesmee - leaving the audience desperate for more.

Comic-Con fans also were treated to a short clip showing the new Bella having to disguise herself as a human. Questions from the audience focused on the actors' personal highlights over the last four years of filming the four movies.

The cast appeared in a jovial mood, teasing each other and sharing stories from the film shoot. Stewart described the experience as a "bittersweet" period. The cast members said Comic-Con provided an opportunity to reconnect with some of their most rabid fans.

Yet the event was marred by tragedy on Tuesday, when a woman died after being hit by a car while crossing the street outside the convention center. She was remembered at the start of Thursday's panel.

"We would like to honor the memory of Gisela Gagliardi, a fan we tragically lost two days ago. We wish her family and friends the best during this difficult time," said "Twilight" panel moderator Eric Moro.