Hugh Grant, Olivia Colman and Keegan-Michael Key also appear in the origin story of Roald Dahl’s magical chocolatier, from ‘Paddington’ director Paul King.

In his Paddington movies, Paul Smith folded animation and live action together into delightful all-ages adventures, selling a message of community and acceptance with spry wit and disarming sweetness, not to mention Ben Whishaw’s impeccable voice work, imbuing the gentle ursine protagonist with genuine heart. Depending on your appetite for sugary excess, you might embrace the director’s Wonka as more of the same. Or you might find the qualities that distinguished his previous hits get steamrolled here by strained whimsy, an aggressive charm that wears you down rather than lifts you up.

Late in the film, Chalamet’s young Wonka croons the lovely song “Pure Imagination” — popularized by Gene Wilder in 1971’s Willy Wonka & the Chocolate Factory — while conjuring the magical manufacturing plant out of thin air. But that CG rendering just underscores the movie’s cloying artificiality. It’s an empty chocolate box.

Farnaby and King’s screenplay strays outside Dahl’s original story to imagine what came before, while remaining more or less true to the author’s thematic playground of pure-hearted children triumphing over wicked adults.

The child in this case is a young man, yearning to purvey the unique chocolate-making skills he learned from his mother but obstructed at every turn by a crooked cartel of well-heeled chocolatiers, Slugworth (Paterson Joseph), Prodnose (Matt Lucas) and Fickelgruber (Mathew Baynton), who welcome no competition to their high-priced goods for sale in the swanky Galeries Gourmet. In addition to the threat of Wonka’s extraordinarily delectable chocolates, there’s also the fact that he wants to make them an egalitarian treat, affordable to everyone. Fickelgruber typifies the cartel’s attitude toward that aim by gagging any time he hears the word “poor.” Which might have been funny if the evil trio hadn’t been pushed to such gratingly arch extremes.

Grotesque villains were a Dahl staple, but because three ruthless capitalists who’ll stop at nothing to protect their monopoly from a talented upstart apparently weren’t enough, the script throws in a coarse innkeeper, Mrs. Scrubit (Olivia Colman), with a mouthful of yellowed teeth right out of The Simpsons’ “Big Book of British Smiles.” Be prepared to see leering closeups of those misshapen chompers too many times to count.

Willy’s key ally, however, is Noodle (Calah Lane), a smart, resourceful girl dropped down the laundry chute as an infant and “taken in” by Mrs. Scrubit. That was supposedly an act of kindness, but in reality, Noodle has been forced into a life of indentured servitude. Young newcomer Lane gives arguably the movie’s most appealing performance, in part because she’s virtually the only one who doesn’t spend the entire time strenuously mugging. I swear, I physically recoiled every time the supercilious cartel reappeared.

Also gorging on the scenery is Keegan-Michael Key as the Chief of Police, on the take from the cartel and accepting payment in chocolate, which causes his girth to keep expanding in a tiresome running fat joke. Rowan Atkinson is a more welcome presence, even if he’s doing his familiar shtick as a similarly corrupt priest. And Hugh Grant is doing, well, Hugh Grant, albeit in miniaturized form, with orange skin and green hair as a dandified Oompa Loompa who keeps stealing Willy’s chocolates until he can be roped into helping out.

In addition to “Pure Imagination,” another of Leslie Bricusse and Anthony Newley’s songs from the 1971 movie, “Oompa Loompa,” resurfaces via Grant, with a reprise over the end credits that wraps up loose plot strands. The serviceable new numbers are by Neil Hannon, frontman of The Divine Comedy, though there’s little of the sophisticated lyrical wit of the Northern Irish orchestral pop band’s best work. The catchiest of the new songs is “A World of Your Own,” nicely sung by Chalamet.