Groening reveals Rogen 'Simpsons' details

Matt Groening has revealed story details for the forthcoming Seth Rogen-scripted Simpsons episode.

The animated comedy's creator told Nuts that Rogen and writing partner Evan Goldberg have penned a script that will see the Pineapple Express star voice Homer's personal trainer.

"He wrote an episode we'll be reading soon, where Comic-Book Guy creates a superhero comic which then gets made into a feature film," Groening explained. "Homer plays the lead and to slim down, Seth Rogen will play his personal trainer."

Despite technological advances since the series's debut in 1989, Groening insisted that the show continues to use traditional animation at the initial stages.

"Every episode is still drawn by hand but we no longer have animators willing to ink and paint actual stories, so it's all done on computer," he said.

"To get continuity with the way the way it was done traditionally, we dirty up the picture and make it look the way it used to, with a lot of dirt on the drawings, so no-one knows it's done by computer."