Let’s cut to the technical stuff: “Step Up 3D” was conceived and shot for the 3-D process, unlike some other recent movies we won’t mention (all right, “The Last Airbender”), which were digitally reworked for 3-D in post-production. So it’s got that going for it.

And, in fact, the film provides a useful case study for the current 3-D craze. We know 3-D can be pretty cool in animated movies and sci-fi spectacles, but this is just a sequel about urban dancing. How well does 3-D enhance an ordinary movie?

Based on this, 3-D won’t cut it. Except for specific dance-related sequences — some of which are truly fun — the 3-D is mostly distracting. Shiny objects tend to throw the balance out of whack (and I mean any reflective surface, like a vinyl jacket or a metal lid), and fast movements are still hard to track.

However, the latter point has actually made something interesting happen with this otherwise laughably dumb movie. The 3-D would look nauseating in the quick-cut style of most dance movies like this, so director Jon Chu and his crew have been forced to shoot many scenes in wide shots, with relatively deliberate cutting.

This means that the dance sequences are much more enjoyable than most music pictures these days, and you can actually appreciate the moves.

Of course, most of the scenes involve large groups of people showing down each other in urban dance-offs, which gives the action a borderline hilarious undertone that occasionally breaks out into, well, overtones. (Translation: Some people will be laughing out loud at this movie.)

The script proves that bad dialogue in 3-D is still bad dialogue. Here we move directly into “Showgirls”-level stuff, as dance-group leader Luke (Rick Malambri) maintains a giant Manhattan warehouse-loft filled with homeless dancers.

In a gesture with “Oliver Twist” suggestions, Luke invites a younger lad (Adam Savani) to join the crew; meanwhile, a mystery woman with miracle abs and mad dance skills catches Luke’s eye.

She’s played by Sharni Vinson, who conjures up the young Demi Moore and is one of the few recognizably human people in the film.

Luke’s evil rival holds the lease to the loft, which Luke will default on if his crew doesn’t win the big prize money in the dance-off.

While watching this unfold, one frequently wonders whether the filmmakers intended “Step Up 3D” to be a parody of itself, so moronic are its plot turns.

One sequence shines: Savani and Alyson Stoner dance down a Manhattan street, in one unbroken take, to a hip-hopped version of Fred Astaire’s “I Won’t Dance.”

I won’t say this scene redeems the rest of the movie, but they did get something right.

“Step Up 3D” ½

The big urban dance-off looms; can our heroes pay the rent by banding together and winning? Will anybody care? The 3-D can’t disguise the awful dialogue, but it does make the dance sequences sort of interesting to watch, as a technical experiment if nothing else.

Rated: PG-13 for language

Showing: Alderwood, Everett, Galaxy Monroe, Marysville, Pacific Place, Thornton Place, Woodinville, Cascade Mall