The future keeps calling for Zoe Saldana and Sam Worthington.
They had breakout hits last summer in established science-fiction franchises, she in “Star Trek,” set in the bright human future of the 23rd century; he in “Terminator Salvation,” set in an apocalyptic wasteland a couple of decades from now.
Now they have a potential science-fiction franchise of their own in James Cameron’s “Avatar,” a 22nd-century space epic that casts them in a love story involving a 10-foot-tall blue alien and a paralyzed human inhabiting a similar body engineered in the laboratory.
Both had been on a gradual rise in Hollywood but were relative unknowns when Mr. Cameron cast them as the leads for “Avatar,” his first narrative film since 1997’s “Titanic.”
After completing the bulk of the work on “Avatar,” Miss Saldana went off to co-star as communications officer Uhura in J.J. Abrams’ revival of “Star Trek,” while Mr. Worthington starred alongside Christian Bale in “Terminator Salvation,” a continuation of the franchise Mr. Cameron started.
“I’ve told Sam that I think it’s … decent of him to go out and become a movie star since he finished ‘Avatar,’ ” Mr. Cameron said. “I thought that was… considerate. And Zoe, absolutely, with ‘Star Trek.’ She was fabulous in the film.”
Mr. Worthington plays Jake Sully, an ex-Marine now in a wheelchair who signs on to help humans obtain an energy-rich mineral on the distant moon of Pandora, where blue natives called Na’vi live in harmony with their world’s environment. Jake is part of the Avatar Program, which transfers human consciousness into Na’vi-like bodies so they can survive on Pandora and interact with the locals.
Na’vi huntress Neytiri (Miss Saldana) winds up as Jake’s reluctant mentor, and the two gradually fall in love and become key figures in a stand against rapacious humans intent on pillaging Pandora’s resources.
Mr. Cameron shot the Pandora sequences using performance-capture technology, the actors performing on a sound stage, their movements and expressions recorded by digital cameras, the exotic features of the characters and other effects added later through computer animation.
Mr. Worthington is featured in human form for much of the film, but Miss Saldana appears only as her Na’vi alter-ego, generally humanoid in shape but with a tail, pointed ears and huge eyes.
“It did kind of hit my ego a little bit that it wasn’t going to be my face. I would not be human if I told you that it didn’t bother me or that that wasn’t something that crossed my mind. It did for two nanoseconds, and then it went away,” Miss Saldana said.
“Because once I understood how the technology was working, I understood the integrity that Jim was going to maintain with our performances, I was like, ‘This is me.’ … I’m so her that I’m there, even though I never was, you know?”
Mr. Worthington also said that for all the extraterrestrial trappings, the Na’vi at their core were the humans who played them.
“The performance is all me. There’s no questions. My mate said, ‘I’m sick of looking at your head normally. Now I’ve got to see you as a … blue alien.’ He goes, ‘And it is you! I can see your smile,’ ” Mr. Worthington said.
“When I’ve seen it, I forget that I’m watching, after all, big, blue aliens, and I see what Jake saw in Neytiri, which is her soul, her spunk, her spirit. I think that’s what translates, more than any other performance-capture movie I’ve seen, which is the spirit of these people, of me and Zoe.”
Miss Saldana, 31, has had roles in such Hollywood films as “Pirates of the Caribbean: The Curse of the Black Pearl,” “Guess Who,” “The Terminal” and “Drumline.” Given the longevity of the “Star Trek” brand name, she has a potentially long career as Uhura and will see more action with the upcoming comic-book adaptation, “The Losers.”
Trained at Australia’s National Institute of Dramatic Art, Mr. Worthington, 33, had small roles in “Hart’s War” and “The Great Raid” and auditioned to become the next James Bond in “Casino Royale” but lost out to Daniel Craig. He follows “Avatar” with another big visual spectacle in 2010’s remake of “Clash of the Titans.”
If “Avatar” proves a hit, Mr. Cameron said he has ideas for two sequels. Miss Saldana and Mr. Worthington are game for a return trip to Pandora.
Like the franchises that grew out of “Star Wars” and “Star Trek,” Miss Saldana said, “I feel that ‘Avatar’ has every potential to carry that torch, as well.”