LOS ANGELES (Reuters) - In a summer swimming in apocalypse movies, Mexican director Guillermo del Toro puts his own stamp on the end of the world with an epic sci-fi battle between monsters and robots, eschewing Hollywood’s A-list for a cast of cable TV actors.

“Pacific Rim,” out in theaters on Friday, sees mankind fighting giant alien monsters called “Kaijus,” derived from Japanese lore, with giant human-operated mechanical robots called “Jaegers,” and taps into Del Toro’s own childhood fascination with Japanese movies and robots.

“I think that the awe we felt as kids watching giant monster movies was lost,” Del Toro told Reuters. “They were so big, so crazy, that they were unreal. ... I wanted to bring it back.”

The film follows a succession of apocalypse disaster movies released this summer, including “After Earth” and “World War Z.” What sets “Pacific Rim” apart is its lack of an A-list film cast.

Rooted in the epic battle scenes are 10 characters connected to the Jaeger program, exploring relationships that include a father-son team, brothers-in-arms and a romance, all of which Del Toro says give the film “heart.”

The director selected actors best known in cult television shows, such as Charlie Hunnam from FX’s drama “Sons of Anarchy,” Idris Elba from HBO’s gritty drug series “The Wire” and Charlie Day from FX’s comedy “It’s Always Sunny in Philadelphia.”

Day particularly impressed the director, stepping out of his eccentric, dim-witted character that he is known for on “Always Sunny” to play the intelligent, fast-talking alien enthusiast, Dr. Newton Geiszler.

“Charlie is known for being great at playing dumb, but I needed him to play super smart, arrogant and still be funny, and he was so great at it, it was a big surprise,” Del Toro said.

“It’s nice to play someone who is more like the guy who writes ‘Always Sunny’ than the guy he plays,” Day added, quipping “my parents were proud.”

As the only lead woman in the male-dominated cast, Del Toro cast Japanese actress Rinko Kikuchi, and said he wanted to steer away from the sexualized stereotypes of women in action movies.

“I really wanted her to have a feminine power. She’s not a character that is trying to be a guy. She’s a character that finds her strength in still being loyal, still being an honorable character,” Del Toro said.

‘ROMANTIC DECAY’

Del Toro, 48, has built a body of works including “Hellboy” and “Pan’s Labyrinth,” exploring sci-fi, fantasy and horror as director, writer and producer.

For “Pacific Rim,” the director was given a budget of $180 million by film studios Legendary Entertainment and Warner Bros., which co-financed the film.

In the end, Del Toro said he came in under budget, but wouldn’t say by how much.

“The best way to be left alone is don’t go over budget, don’t go over schedule. Not only did they not interfere, but they were super supportive,” Del Toro said.

“Pacific Rim” is Legendary’s final film with Warner Bros., a unit of Time Warner, before it enters a new contract with Comcast’s NBCUniversal.

Del Toro said he wanted to set his film apart aesthetically from the rest of summer’s action movies, opting to use a warm saturated palette of colors that are brought to life in 3-D.

“I didn’t want to do the usual super-sleek look that action movies are getting for the last 10 years. ... I wanted to have an almost romantic decay - everything looks damaged, peeling and used,” the director said.