Immortals might take its characters from Greek mythology, but the movie’s 3-D visuals look anything but familiar.

In the exclusive behind-the-scenes video above, members of the effects team explain how director Tarsem Singh pulled off the film’s epic, eye-popping battles and stamped the ancient story with a grand style all his own.

“There’s major computer-generated effects, but it still has to be a marriage between physical effects and the computer world,” says special effects supervisor Ryal Cosgrove in the clip. More than a dozen physical sets were built and stitched together with virtual environments.

The filmmakers also utilized technology used in Avatar to make it possible to see what actors would look like within the movie’s virtual world. The system “allows Tarsem and the staff to see exactly what’s going to be green screen, and what’s going to be set,” says Jeff G. Waxman, Immortals’ executive producer.

Preview footage screened in 3-D at this summer’s Comic-Con International showed off some of the movie’s stunning fight scenes.

Director Singh, who directed 2000 sci-fi thriller The Cell as well as R.E.M.’s classic “Losing My Religion” video, said to expect a brutal retelling of mythic stories in Immortals, in which King Hyperion (played by Mickey Rourke) leads the Titans in a war against humanity.

“It’s a little darker than what I think the trailers lead you to believe,” Singh said at the time. “The trailers that you see have been for everybody. The movie’s a little more hard-core than that.”

The R-rated Immortals — which stars cinema’s next Superman, Henry Cavill, as Theseus — opens Friday.