A few weeks ago, Lars von Trier’s “The House That Jack Built,” starring Matt Dillon as a Pacific Northwest serial killer with a pushy manner and a twisted smile, opened on 32 screens and grossed just $34,000 — a little over $1,000 per screen. That is, by any standard, an abysmal opening, but it’s a genuine eyebrow-raiser when you consider that “The House That Jack Built” was designed to be a chatter-stoking, headline-fueling succés de scandale, the sort of Lars von Trier smoke bomb that might fulfill itself even in the audience’s loathing for it. Instead, it provoked something that any filmmaker worth his salt should fear far more than loathing: indifference.

If a born-to-be-bad Lars von Trier movie falls in the forest and no one hears it, does it make a sound? Von Trier’s films, like “Jack” or the two-part epic transgressive ramble “Nymphomaniac,” have been failing to set the art-house world on fire for a while now. But considering that “The House That Jack Built” stars Matt Dillon in a committed and far from uninteresting performance, and that it features a high-intensity cast of victims (Uma Thurman, Riley Keough) and ends — literally — in the bowels of hell, it should have at least been a conversation piece.

Yet it’s as if the whole buzz cloud of outrage has passed von Trier by. People have grown weary of debating his films, of parsing his provocations and kinks and tricks and subversions, his balancing act of austerity and shock, his moral immorality, and his scenes that play out in that familiar jagged mode of raw-light verité — only now, too often, his atmosphere of documentary randomness doesn’t mimic reality so much as it evokes the image of a director making up his movies as he goes along, letting his actors improvise because he can’t be bothered to hammer out a script beyond the basic situations he comes up with. He’s become the Nordic John Cassavetes of sensationalist art porn.

I saw “The House That Jack Built” at its premiere showing at Cannes last May, and far more dramatic than anything in the movie was von Trier’s entrance into the Grand Théâtre Lumière. It was his first time back at Cannes since 2011, the year of the infamous press conference at which he appeared to offer a perverse apologia for the Nazis (he impishly confessed to identifying with Hitler). Since then, he has spoken of his clinical depression, but was even that declaration of a serious mental-health condition a rationalization for his behavior or, on some level, another von Trier prank? In the Palais, if you studied his face, searching for a glimpse of what he was feeling, you weren’t going to find it. Because he wasn’t about to let you.

Von Trier, who turned 62 last year, is still handsome, shaggy-bearded and with longish hair in place of his former trademark close-cropped cut. As he strolled along the Cannes red carpet and ambled into the theater, he met the standing ovation that greeted him with a frozen Cheshire cat smile that was at once sinister and mysterious. He held that look for 10 minutes straight. Maybe he was just uncomfortable, but it felt as if he’d consciously sedated his own spirit. It was hard not to imagine him thinking something like, “Yes, I’m back, but that doesn’t mean I’m sorry,” or even, “I’ve made a film about a serial killer because, frankly, that reflects how I feel about all of you.” Or maybe he really just wanted everyone’s love and adoration. God only knows what he was thinking.

God, in fact, is a character in von Trier’s greatest film, “Breaking the Waves.” Emily Watson’s Bess talks directly to God, and then God acts, damaging her husband so that he’ll return home to her, which is why she then destroys herself to save him. But the mystique of von Trier’s movies is no longer about a place where the pain of life touches the transcendent. It’s about alienating the audience as a postmodern form of showbiz.

His most vibrant period — “Breaking the Waves” (1996), “The Idiots” (1998), “Dancer in the Dark” (2000) — was the second half of the ’90s, and that’s now a long way back. Since then, he has made enough “visionary” misanthropic whose-side-am-I-on art stunts, like the in-your-face stilted “Dogville” or the scenes-from-a-sadomasochistic-marriage drama “Antichrist” or that apocalyptic tale of depression-meets-rogue-planet, “Melancholia,” or “The House That Jack Built,” to have turned himself into the P.T. Barnum of savage austerity. Except that no one’s coming to his circus anymore.

So maybe it’s time for von Trier to give himself an intervention, to admit to himself, quite simply, that what he’s doing is no longer working. It’s not connecting, it’s not making a statement about anything beyond the cult of himself — and, bluntly put, it’s not good art. It’s crawling into a black hole and pretending that’s a way of seeing the light.

He’s got to find a new path. But I think that if he did, he could still blow the world away. Imagine if von Trier set aside his shock theatrics and stripped his filmmaking down in a new way, making a drama about relationships that was about nothing but…relationships. What if he forced himself to get back to the basics of his humanity? I think if he tried that, he might soar. Just watch “Breaking the Waves” again: It’s an extravagant tale, and stylistically it may seem to be of a piece with what he’s doing now, yet its tone is so different. Scene to scene, it’s more tender and inquiring; it’s grounded in sincerity. There was a glimmer of innocence to Lars von Trier back then, before he’d wowed us all. But along the way he got addicted to pushing our buttons, and it’s an addiction he needs to shake. Because no one cares anymore about a former great filmmaker who’s now falling in the forest.