The arthouse erotic psychodrama, already territory heavily land-mined with projects of dubious intent, is done no favors by the pornographic posturing of German writer-director-actor RP Kahl’s turgid “A Thought of Ecstasy.” Strongly making the case that aside from other people’s dreams and other people’s holiday photos, there’s nothing drearier than other people’s sexual fetishes, the film even has the gall to chip away at the legacy of one of the genre’s few masterpieces.

Deborah Kara Unger (who also executive produces) husks and purrs through a “Red Shoe Diaries” version of the icily dehumanized femme fatale she embodied in David Cronenberg’s “Crash,” which only serves to illustrate the yawning gulf between the two films: One is about a deadening sexual obsession with car crashes while the other is itself a deadening car crash about sexual obsession. The only good news is that “Ecstasy” is so committed to its full-frontal nudity, erect penises, exposed vaginas and unsimulated sex scenes that it’s unlikely to penetrate wider markets, or to register anywhere but nichier festival sidebars.

Things start on “the hottest day ever recorded,” though nobody looks particularly overheated, and Kahl maintains his pinkly bald pallor throughout. The year is 2019 — future-y enough to give the film pretensions of dystopian sci-fi, especially in its air of sterile unreality, but not so far off that Kahl has to bother imagining any future-world-building details. One exception: In a flailing grab for topicality, a radio report mentions the Big Wall, which is presumably Trump’s proposed Mexican border wall, but that’s largely the last we hear of it.

Kahl plays Frank, a German man scouring the California desert for Marie, a woman he had a torrid affair with a while back. Her memoir of those heady days has just become a bestseller, under the nom de plume of Ross Sinclair, in just one of the film’s would-be provocative but actually just self-justifying twists on gender, authorship and control. Unger reads from this book in woozy voiceover, which is bad enough, but then the actual dialogue starts. Kahl’s heavily accented English leads to line readings in which the stress points in a speech like “I’m Frank I am a character in the book no not a character I am Frank” seem to land more or less at random, and irresistibly recall the cadences of Tommy Wiseau’s eccentric delivery.

On this odyssey, mostly described in interminable shots of Frank driving punctuated by graphically sexual dream sequences, he is directed to a particular bunker by Unger’s mysterious Liza. There he encounters Nina (Ava Verne), a sex worker who services her clients in elaborate scenarios and films the encounters. She’s hanging from a hook, being whipped on the thighs, nipple-clamped and slapped all over by a man wearing thick rubber gloves and what looks to be a mask of Odo from “Star Trek: Deep Space Nine,” as Frank watches gormlessly from the red-lit shadows and a moth flutters around worriedly.

Those aren’t just Nina’s thighs reddening, they are Verne’s and that really is her flinch-response to pain. If a key part of the artistry of cinema is artifice, the “realness” of these and other sex scenes displays all the anti-cinematic clumsiness of pornography: Why must these moments be “authentic” when absolutely nothing else in the film is? Inside the movie’s airless world, the sadism is excused by Nina seeming to get off on it. As the embodiment of the pernicious male fantasy of a woman turned on by her own degradation, Nina becomes a handy justification for the po-faced perviness of the movie’s unremitting male gaze.

Frank starts to work for Nina, who sometimes performs with another young woman (Lena Morris) who very much resembles Marie, prompting even more tedious fugue-state philosophizing. And so the director of the movie becomes the director in the movie, a mind-blowing metatextual twist that gives this extravagantly irritating film another dimension in which to irritate.

The sleazy, knockoff-Lynchian milieus of “A Thought of Ecstasy” are competently shot by Markus Hirner, and the film boasts a strong electronic score from members of Moderat and Modeselektor that lends music-video gloss to some of its longeurs. And it’s performed by its actresses with a level of literally naked commitment that the solipsistic material hardly deserves. As the credits roll, it’s with them and not Frank that our thoughts linger, and despite the inevitable closing Baudelaire quote, it is a line of Unger’s narration that sums up the essential tragedy in that respect: “I became a movie star of films no one would ever see,” she breathes, prophetically. Maybe in this case, that’s a mercy.