That legend has been sustained by earlier movies, notably Vincente Minnelli’s rumbustious “Lust for Life” (with Kirk Douglas as van Gogh) and Robert Altman’s more cerebral “Vincent & Theo” (starring Tim Roth and Paul Rhys as the brothers).

Vincent himself (Robert Gulaczyk) is a more elusive presence in “Loving Vincent,” since most of its action is posthumous and self-portraits make up a relatively small part of his oeuvre. There are flashbacks, but the painter is evoked mainly through the dialogue of the other characters, as if he were the Maltese Falcon.

The principal mystery is the stuff of police procedural, as Armand doggedly tries to reconstruct van Gogh’s final weeks and shed light on the circumstances of his death. How miserable was he, and why? What secrets did he harbor? What enemies had he made?

The questions are interesting, but not quite sufficiently dramatized to sustain “Loving Vincent” for its full length. As the story limps and drags, the viewer also becomes accustomed to the images, and astonishment at the film’s innovative, painstaking technique begins to fade. But its charm never quite wears off, for reasons summed up in the title.