The film's animation director Mike Cozens and VFX creative director Eric Saindon visited Beijing to unravel the advanced technology behind the scenes. [Photo provided to chinadaily.com.cn]

They revealed that around 800 people, or half the entire staff in the Oscar-winning concept design studio Weta Workshop, joined the digital project for Alita: Battle Angel.

Their jobs are complex, including digitally transforming American actress Rosa Salazar's performance into the computer-generated role of Alita, the titular female cyborg who looks like a beautiful young woman.

To make the protagonist as authentic as possible, they created for her 132,000 strands of hair, 2,000 eyebrows, 480 eyelashes and nearly 500,000 particles of downy fluff on the face and ears.

"You'll forget she is a CG character when you are watching the film," says Saindon.

To bring to life Iron City, the main setting of the film, the crew built a venue covering an area of 96,000 square feet in Austin, Texas. Additionally, to simulate human movements underwater, they recruited an actress to hold her breath and walk at the bottom of a swimming pool for six minutes.