Renoir is a ravishing new biopic from director Gilles Bourdos that gives us two geniuses for the price of one. For most people the name is synonymous with the paintings of Impressionist master, Pierre-August Renoir. Cinephiles will also know that his film-maker son, Jean Renoir, is equally celebrated as the writer/director of La Grande Illusion and La Règle du Jeu. But you’re unlikely to have heard of the central figure in this drama, actress Catherine Hessling (born Andrée Heuschling), who briefly achieved fame in the 1920s and was the first wife of Jean Renoir.

In 1915 the calm atmosphere of the Renoir villa at Cagnes-sur-Mer on the Côte d’Azur is disrupted by the arrival of Andrée “Dédé” Heuschling (played by Christa Theret). This auburn-haired beauty was engaged by the recently deceased Madame Renoir to model for her ailing husband. Thanks to his beguiling new muse, Renoir (played by veteran Michel Bouquet) is soon rediscovering his appetite for painting nudes. When his son Jean (Vincent Rottiers) comes home to recuperate from a war wound, he too is captivated by this self-confident young woman who dreams of a career as an actress. That romance is overshadowed by intergenerational tensions and by the prospect of Jean’s return to the carnage and chaos of the front.

It’s no surprise that Renoir is a film minutely preoccupied with flesh and the female form. As in La Belle Noiseuse (1991), we witness the interaction between artist and model, and the painstaking process by which life is infused into canvas. There are excursions to the beach and the countryside, with Mark Ping Bing Lee’s photography bathing the unclothed Dédé in golden hues that are perfect for Renoir senior’s brushwork.

. . . when a woman strips off for her art audiences tend not to remember the acting.

Renoir is more than just chocolate-box beauty and tableaux vivants. The men appear cloaked in an aura of death and decay, as the film contrasts Renoir’s art with the inescapable effects of war and ageing. The wheelchair-bound painter consults with his doctor; his swollen and arthritic hands are bathed and bandaged by his retinue of devoted female servants so that work may continue. Jean dresses the ugly wound in his leg, as younger brother Coco (Thomas Doret from The Kid with a Bike) looks on. We also glimpse horribly disfigured war veterans in one of the film’s few scenes outside the Renoir estate.

With all this material to work with, it’s disappointing that Bourdos fails to get under the skin of his characters. Renoir senior’s pronouncements rarely get beyond the level of clichés that do little to illuminate his strained relationship with his sons. Thomas Doret impresses as the sullen adolescent, whose budding interest in the opposite sex is fuelled by the presence of “Dédé”. Though Vincent Rottiers looks nothing like the man who became a giant of European cinema, he effectively conveys the conflict of a man torn between his love for Dédé and his duty to fight on.

Christa Theret has the most difficult role here – not just because when a woman strips off for her art audiences tend not to remember the acting. As the mercurial Dédé, it’s her scenes of conflict with the disapproving female servants and the Renoirs that bring this rather slow-moving narrative to life. The young model’s frustration at her constricting role within the household is finally laid bare when sulking gives way to a bout of plate-smashing. But this would have been more believable if we had ever glimpsed her life outside the house or saw her confiding in a friend. The Renoirs are so insular and so immersed in their own affairs that they have no idea where she lives.

Despite the weaknesses of the script, Renoir does offer glimpses of the challenges faced by a great artist battling on despite waning physical strength. Viewed as a series of picturesque vignettes of summer on the French Riviera 100 years ago, it is a lovely film to watch. But given that Dédé and Jean later married and made films together, you might feel that Renoir demands a sequel. I ended up wishing that Bourdos’s film had been less reverential and made more of a drama out of the Impressionist maestro’s late-life crisis.

Renoir is released in selected UK cinemas on Friday 28 June 2013.