Heroine Bai Qian (Liu Yifei) and Prince Ye Hua (Yang Yang) in the fantasy-romance “Once Upon a Time.” (Well Go USA Entertainment)

Personal identity is as complicated as the plot in “Once Upon a Time,” a CGI-heavy Chinese fantasy-romance. Heroine Bai Qian (Liu Yifei) is a goddess who can transform into a multi-tailed white fox. She’s also the exact double of Susu, the lost love of Prince Ye Hua (Yang Yang), who looks just like — well, that’s supposed to be a surprise.

The movie was directed by Zhao Xiaoding and Hollywood special-effects veteran Anthony LaMolinara (whose credits include 2004’s “Spider-Man 2”). The elaborately costumed actors travel through a computer-generated magical universe and interact with animated characters (mostly realistic, although one incongruously resembles Sprout, Green Giant’s former spokes-vegetable). The imaginative visuals upstage the battle scenes and amorous intrigues.

“Once Upon a Time” derives from a Chinese novel, “Three Lives Three Worlds, Ten Miles of Peach Blossoms” (published in English as “To the Sky Kingdom”). The story is so involved that a recent Chinese-TV adaptation of the book ran for 58 episodes. This movie’s condensed telling is somewhat bewildering, although the essentials eventually become clear. But then they’re really just a pretext for such fairy-tale wonders as an underwater city, a living island and a hummingbird air force.

Unrated. At Regal’s Rockville Center Stadium 13 and the AMC Loews Rio Cinemas 18. Contains violence and wine-drinking, including by a child. In Mandarin with subtitles. 108 minutes.