Katy Perry: Part of Me is a slick, polished portrait

This film image released by Paramount Pictures shows Katy Perry in a scene from her 3D film, "Katy Perry: Part of Me." (AP Photo/Paramount Pictures)

Its a good thing the makers of Katy Perry: Part of Me arent in politics. Theyd probably steal the election.

• Singer Katy Perry takes the stage performs with dancers in her new 3D film, Katy Perry: Part of Me.

Part of Me and its forerunner, Justin Bieber: Never Say Never, are mesmerizing pieces of pop propaganda. Both 3-D concert films give a reality TV-style portrait of a young star, scrubbed clean, at the pinnacle of pop: touring sold-out arenas while making Herculean sacrifices, always finding time for their fans and goofing around with their entourages of stylists and assistants.

Theyre unabashedly commercial movies made about unabashedly commercial enterprises. And yet theyre kind of fascinating.

Thats because Part of Me is as good a document youre likely to find of modern pop stardom: how its packaged, how its sold and what kind of power it holds over screaming tween girls.

The film, directed by reality show veterans Dan Cutforth and Jane Lipsitz (the pair prod! uced Nev er Say Never, as well as shows like Top Chef and Project Runway), follows Perrys 2011 California Dreams world tour. The 124-concert extravaganza came on the heels of her hit album Teenage Dream, the only album to chart five No. 1 hits for a female performer.

A large chunk of the film is made up of 3-D footage of the concerts (songs like Firework and California Gurls) performed on candy-colored stages that look like Willy Wonka threw up on. (All of the footage was shot by other filmmakers and later assembled by Cutforth and Lipsitz, who came aboard only to stitch the film together in editing.)

But much of the documentary is spent telling Katys story, and certainly, the blue-haired, dinner-plate eyed 27-year-old makes for a compelling character. Raised by traveling Pentecostal ministers, Perry first tried Christian songwriting as a 13-year-old and later, in Los Angeles, went through various incarnations before emerging as a star with I Kissed a Girl.

As artificial as much of the apparatus surrounding Perry may be, none of it works without her charisma at the center. That comes through in Part of Me, as does her intense drive to succeed after early failures. Many of those who helped along the way are here to sing her praises and take credit for their foresight of her talent, like her slick manager Bradford Cobb.

Part of Me, though, doesnt succeed as a full picture of Perry. A less PG-friendly, more complicated version of the star surely exists off-screen. The film often feels like a tease, showing only, well, part of Perry.

The money shot of the film is when cameras catch Perry crying in her dressing room following her split from husband Russell Brand (whos seen fleetingly backstage).

Its an honest moment. The finest shot of Part of Me is Perry seconds before she goes on stage that night in Sao Paulo, Brazil, bent over sobbing and then seconds later with the professionalism of a true performer papering over the heartbreak with a broad smile while chants for Kay-Tee! roa! r and th e peppermint-colored wheels on her dress start to spin.

The moment would mean more if it was accompanied by more context of Perrys emotional life, rather than served up as evidence of her humility. But thats the sleight of hand of Part of Me, which can even use genuine sorrow to feign depth.

Watching Part of Me through aqua- and pink-colored 3-D glasses in a crowd of girls singing along, Perrys songs dont feel vapid but rather like anthems of self-empowerment. The pop experience exuberant, superficial, fun, crass could hardly be mirrored better.

KATY PERRY: PART OF MEStarring Katy Perry. Directed by Dan Cutforth and Jane Lipsitz. Rated PG. Opens today at Cinemark Movies and Premiere Cinema.