With more than a decade of experience under his wig, 29-year-old Brian Firkus, who performs as the self-professed comedy queen Trixie Mattel, has become a wildly popular fixture on the drag queen circuit.

The documentary "Trixie Mattel: Moving Parts" — which closed out the All Genders, Lifestyles and Identities Film Festival, or AGLIFF, on Sunday in Austin — follows the effects of that fame on Mattel, who competed on the seventh season of reality TV competition "RuPaul's Drag Race." Viewers see the performer going into the studio to record two country music albums inspired by Dolly Parton, touring the world and gearing up to be a contestant on the third season of "RuPaul's Drag Race All Stars," which Mattel ultimately won.

Seeing that this documentary is produced by World Of Wonder, the company that brought the "Drag Race" franchise into the world, you might anticipate it to be strictly a slick, happy promotional montage. However, that isn't what viewers are in for at all.

Whenever Firkus exhibited traits perceived as feminine as a child, his stepfather would call him a "trixie." Turning that pain into an entire career is a big part of what makes this documentary so compelling. Not only has Firkus dealt with mental anguish from a traumatic childhood ("When you're in it, you just think it's normal," the performer says), but the cameras were also rolling on this film when his comedic partner, Brian McCook (aka Katya Zamolodchikova), walked away from their hit Viceland TV show to enter rehab.

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If this movie were positioned as more of a "puff piece," it's unlikely that director Nick Zeig-Owens could have gotten away with leaving some of the most painful and raw moments in the final cut. One particularly rough sequence takes us backstage right before a Trixie Mattel show on an overseas tour, where a series of mean text messages received from McCook right before going on stage shakes Firkus' confidence. But, as they say, the show must go on, and the adoring fans are never the wiser.

This isn't all to say that the movie is without humor — there are laughs. Whether in full drag as Trixie or out of character in his daily life, it is clear that Firkus is a survivor and most interested in using his talent as a drag performer to get people interested in the songs he's writing and performing. For those two things to co-exist might seem strange on the surface, but watching the actual stage show proves how successful Firkus is in both worlds.

"Trixie Mattel: Moving Parts" filters the drag queen's occasionally twisted comedy through a lens of pure honesty and melancholy. It will satisfy existing Trixie Mattel fans while also serving as a solid introduction for any latecomers.