It’s always nice when a film’s press notes, along with blowing smoke up our skirts about how great the movie is, also tell us why it’s so flawed.

Witness the notes on “Perfume,” the new film from director Michael Rymer:

“All the dialog in ‘Perfume’ was completely improvised by its actors. And while each major storyline had its own ‘arc,’ each actor brought their own experience and skills to their scenes, creating their own characters — and often changing the film’s entire story — as they worked.”

Did you notice the clause set apart by dashes? “And often changing the film’s entire story.” Ah-ha! No wonder all the separate plots don’t gel into a unifying whole! No wonder they all have so little to do with each other, or with any kind of overriding theme! No wonder some of them are boring! It’s because the actors, while given something basic to start with, often changed the story as they went, thus preventing the possibility of knowing the end from the beginning and acting to build up to it.

You can see this in the film. It’s like a bunch of people got together to build a house, except they were allowed to ignore the blueprints (which were vague to begin with) and do whatever they wanted. And so people would build rooms without doorways, and put staircases on top of closets, and cut out windows wherever they felt like it, all without thought to how the finished product would look. They were having too much fun “experimenting” and being creative, and to heck with the team effort!

“Perfume” is not a bad movie, per se, though it’s not a good one, either. It’s allegedly about the fashion industry, though its billing as a “parody” of that world is utterly false. It’s not a parody of anything, except maybe the art of filmmaking, and I think that was unintentional.

At the center (more or less) is Roberta (Rita Wilson), a designer with a major show in four days whose star, Camille (Leslie Mann), is dropping out in favor of seeking greener pastures. Specifically, she’s sleeping with Jamie (Jeff Goldblum), who’s with the very powerful Fantasia agency.

There’s also a photographer named Anthony (Jared Harris) who never has time for his wife. One sentence is all that subplot deserves.

There’s also a magazine editor named Janice (Joanne Baron) whose long-estranged daughter Halley (Michelle Williams) shows up. Janice, all unctuousness and insincerity, has some legitimately funny lines (condescending to a colleague: “It’s cute that you’re trying to make a joke”). I would like to have seen more of her and less, say, of Jeff Goldblum’s typically Goldblumian rambling.

Finally, the best plot has to do with gay designer Lorenzo (Paul Sorvino), who is dying of cancer and is surrounded by a son (Michael Sorvino) he doesn’t trust to leave the business with, and a lover (Peter Gallagher) who is too young for him.

Paul Sorvino is the highlight of the film. The scene in which he finds out he is dying is why improvisational acting can sometimes work. Actors know what sounds trite and what sounds sincere — they spend their days memorizing lines of both sorts — so when they want to sound real, they know what to avoid. It would have taken an excellent screenwriter to handle the scene better than Sorvino handles it off the cuff. If only his character’s story weren’t limited in screen time in favor of one-scene cameos by the likes of Harry Hamlin, Kyle MacLachlan and Mariel Hemingway. Many scenes are interesting simply because they’re so well-acted, but it’s awfully frustrating to realize none of them is really going anywhere.

As an experiment, “Perfume” is fairly successful. Give Rymer credit for getting his large cast of actors to do what he wanted, anyway. But as a movie, “Perfume,” well, stinks.

C (; R, frequent harsh profanity, some nudity.)