A slight but engaging vignette about the peculiarities of the artistic temperament, “Final Portrait” is based on American art critic James Lord’s account of sitting for a portrait by Alberto Giacometti in 1964 Paris, a couple of years before the artist’s death. Marked by a showily virtuoso performance by Geoffrey Rush as Giacometti, Stanley Tucci’s film—his first since “Big Night” in 1996—doesn’t do much, but the little it does, it does pleasantly enough.

Lord (Armie Hammer) was about to leave France for home when Giacometti suggested that he sit for a portrait—something, he opined, that would take just a couple of hours, an afternoon perhaps. Flattered, Lord readily agreed, only to find the process dragging on for weeks as the artist repeatedly insisted on obliterating what he’d done and starting over and over again after expressing dissatisfaction with how it was going with a single expletive. Lord was reduced to repeatedly postponing his departure, much to the chagrin of his boyfriend back in New York, while trying to repress his own growing irritation at being trapped by his desire not to offend the great man.

But it’s not merely the painting, and the artist’s penchant for breaking off work for walks and food, that slow things up; Giacometti’s domestic affairs are also an issue. Though he lives in a ramshackle place with his wife Annette (Sylvie Testud), he’s obsessed with Caroline (Clémence Poésy), a perky but demanding prostitute who has become his new muse and distracts him from the portrait whenever she deigns to drop by. Annette has taken her own lover (Takatsuna Mukai) in return, though we see very little of him.

Watching everything with a sympathetic air, but determined not to get overly involved, is Alberto’s brother Diego (Tony Shalhoub, one of the stars of “Big Night”), who remains unflappable in the face of what seems fraternal chaos, which allows for some amusing digressions—a visit to Caroline’s pimps and Giacometti’s occasional outbursts against fellow artists among them.

Working from Lord’s memoir, Tucci has himself fashioned an affectionate portrait of the artist an immensely talented eccentric, and his direction keeps things moving, the overall tempo and mood nicely judged—a feat aided by the nimble cinematography by Danny Cohen and Camilla Toniolo’s editing. The able efforts of production designer James Merifield and Liza Bracey add to the look of seedy disorder in the Giacometti household, while Evan Lurie’s unobtrusive score supports the action nicely.

But it’s definitely Rush who gives the film the punch it needs, offering one of his most flamboyant performances—which, given his past penchant for extravagance, is really saying something. One can’t say that Rush penetrates very deeply into the artist’s psyche, but in the externals he’s enormous fun to watch, and brings a good deal of humor to his turn. By contrast Hammer can’t provide much beyond general elegance and an underlying touch of exasperation, but his handsomeness certainly fills the bill, and Shalhoub brings understated but undeniable charm to Diego’s preternatural patience. Of the women, with a minimum of fuss Testud captures the various sides of Annette, but Poésy’s Caroline is a rather one-dimensional flirt, though she’s certainly very attractive.

If you think of it in terms of gallery exhibits, “Final Portrait” is pretty much a one-man show, but thanks to Rush it’s one worth a visit.