The 90-minute, needlessly 3D documentary Katy Perry: Part of Me is a fantastic document of how guarded our superstars come in 2012. There's more revealed about Madonna in a single snort or eye roll in 1991's Truth or Dare than there is Katy Perry in the entirety of Part of Me. We learn that being a famous singer is Perry's childhood dream come true, that her goal is to make people smile, that she's not yet ready for kids. The biggest revelation is that she looks fantastic out of makeup, and if the words in her Proactive commercial are true, even that shouldn't come as a surprise. No warts at all.

Perry is the blandest of pop's current heavyweights, a mediocre, Alanis Morissette-influenced singer and decent hook crafter who peddles individuality via the day-glo wigs that everyone else is wearing and whose 2011 tour (profiled in Part of Me) gathers its influence from The Wizard of Oz, Alice in Wonderland and Candyland. "How can you be too cartoony?" she asks as she's trying out costumes for the show. It serves as an inadvertent statement on her unidimensionality.

In one of several of the movie's live musical numbers, Perry performs a cover of "I Wanna Dance With Somebody (Who Loves Me)" in a polka-dot dress and blue wig, pulling kids out of the audience to join her and someone in a giant purple cat costume in an onstage dance party that is about as cool and wild as a Wiggles concert. "Thank you so much for believing in my weirdness," she tells the crowd at the song's end. If she thinks that's weird, Cirque du Soleil would probably melt her mind.

Self-awareness is elusive, especially when you hear as much noise about yourself as a celebrity does, but even its subject must know that Part of Me is straight-up Katy Perry propaganda. It should come as no surprise that she put up $2 million of her own money to fund it. We see fans who sometimes refer to themselves as "Katycats" babbling into their webcams about how wonderful Perry is, how she turns on inner lights and makes one kid think that "being weird is OK."

The film is padded with countless talking-head interviews from her inner circle who praise her for hiring them and generally effuse about the one-woman industry that's paying their rents. Someone actually says, "She writes these lyrics — they're from her diary," over the opening strains of "California Gurls." (I'd love to see that original entry: "Dear Diary, Today was so hot. I wore my daisy dukes with my bikini on top and the sun kissed my skin. I ended up melting someone's popsicle, LOL! OK, gotta go fuck an alien. Peace! Love, Katy.")

Her disciples also talk at length about how hard she worked at her 14-month marriage to Russell Brand. They're paid employees vouching for her – imagine that! On the Brand beat, we see her attempting to schedule visits with her then-husband around her days off. She moans when he doesn't come to her. A good chunk of the movie is devoted to arguing just what a great wife she was.

Katy Perry: Part of Me has a shred of the objectivity of an episode of the always-flattering Behind the Music. But the movie is just as perfunctory and carefully-calculated in charting her rise to fame from living a closed-off life as a pair of preachers' daughter to working her way up through the Christian scene, hanging out in L.A. (the Cobrasnake on her early days about town: "She made you feel, like, happy"), and finally her break into pop music. Her pre-signing association with Glen Ballard is detailed; her collaboration with producers Dr. Luke and Max Martin, who are just as responsible for her current sound as she is, goes entirely ignored.

The only moment that doesn't come off as the kind of fluff that Perry poses upon on her album covers happens before a show: with her marriage definitively over, the pop star sobs inconsolably on camera. She cries, gets her makeup put on, has a team huddle and then cries some more. We see this last instance through a slit in a curtain that gives the scene a voyeuristic touch that the rest of this film lacks, to its own detriment. After, Perry picks herself up and performs onstage and we at last get a tangible contrast between our lives and those of the stars. In this situation, any normal person would be able to take a moment — or, hell, the entire day off — but Perry is contracted to perform. So she does. It's an unenviable snapshot of an emotional life that's been hijacked by public obligation.

That said, even at its most candid, Part of Me underwhelms. Regarding the split, the particulars are left out. We have no idea what conversation led to this final decision or what issues were at the heart of Perry and Brand's irreconcilable differences. All we see is a woman who claimed she did her best and still found herself hurting, anyway. When she actually speaks about the split, she does so vaguely and in a canned talking-head interview. True to its name, at no point does Part of Me ever feel complete.