★ out of four stars

Rated: R. 

After his superb feature debut with “District 9,” South Africa’s Neill Blomkamp was hailed as science fiction’s dystopian savior, the visionary who could combine Orwellian political themes with breathtaking action. But after leaving many viewers feeling burned with “Elysium,” his third film will char them to cinders. “Chappie” is sappy. There’s a better rhyme but it’s not a word used in family newspapers.

Set in a future only months away, “Chappie” imagines that Johannesburg’s violent gang problems have been passed on to an army of robocops. The new creations, resembling tall, trim titanium athletes, police the daily mayhem with criminally lethal efficiency. Their internal programming frees them from the direct human guidance that had powered their bigger, clunkier predecessors.

To Deon Wilson (Dev Patel), their corporate manufacturer’s lead designer, that characteristic makes the new variety a morally promising breed. He hopes to connect them to an artificial intelligence that can make them smarter and more ethical than humans.

Deon’s competitive rival engineer, Vincent Moore (Hugh Jackman), resents the way the new robots are sucking financial resources from his older battlebots. A military vet with conservative religious dogmas, he thinks humans should remain the bots’ godlike controllers. With his mullet haircut, repeated signs of the crucifix and office wear of khaki shorts, he’s clearly a troublemaker. Sigourney Weaver, appearing briefly as their profit-focused corporate overlord, has little more than a walk-on.

The engineers’ competition jumps a level when a model Deon is trying to build in secret is grabbed by second-rate gangstas Ninja and Yo-Landi (played by South Africa’s hip-hop duo Die Antwoord). In order to pay off a far tougher crime boss who threatens to kill them unless they deliver millions within a week, the pair try to teach Chappie, as Yo-Landi names him, their view of the world, largely consisting of trash talk and gunfire.

However, Chappie changes them more than they educate him. He brings out fond parental impulses. Vincent, meanwhile, sets out to find the missing robot and crush Deon’s career.

As baby-talking Chappie matures in a matter of days, the story becomes a misfired mixture of Pinocchio and Jar Jar Binks. “Chappie” once again shows Blomkamp’s incredible lush visual imagination, and his far smaller story sense. There is not a shot lacking fascinating design or documentary-style energy. From the tormented circus of Johannesburg’s rotting buildings to the many body-blasting mob battles or Chappie’s slapstick approach to fisticuffs, the film is beautifully composed and endlessly watchable. But alongside its cinematic realism is stylized fantasy that’s utterly careless.

Blomkamp’s regular star Sharlto Copley portrays the computer-generated Chappie with the sort of motion-capture performance that has given Andy Serkis lifetime employment in Peter Jackson’s Hobbit epics. But the character is an unlikable figure of satire, entirely devoid of humor. None of the characters go beyond a single dimension. That’s understandable when the film’s actual stars are a couple of non-acting rap stars, but with dynamos like Jackman, Patel and Weaver in half-developed roles, it’s a wearying waste of time.