PlayThe animated comedy Ice Age: Dawn of the Dinosaurs is the eighth movie Hollywood has released this year in 3-D. By the end of 2009, there will have been 13 films for which audiences will have worn special polarized glasses, compared with just one in 2003 — and none at all in the decade before that.
The 3-D revolution is really and truly with us, in other words — so without pretending we're going into too much depth, let's have a look at three dimensions of the latest Ice Age iteration that really matter:
Dimension One: Characters. Start with Scrat, that single-minded saber-toothed squirrel, still sniffing and snuffling in search of his beloved acorn.
As always, he finds it, and as always, something keeps him from enjoying it — in this case a squirrel-fatale who's every bit as acorn-crazed as he is. At first they have a Road Runner/Wile E. Coyote-type relationship, but her hold over him becomes progressively more domestic until he's a henpecked hubby, rearranging the furniture in their love nest while gazing longingly at the acorn from afar.
Also back for another round: woolly mammoths Manny and Ellie (voiced by Ray Romano and Queen Latifah), who have a mini-mammoth on the way. That happy expectation means their hapless little chosen family of ice-age misfits — Diego (Denis Leary), a saber-toothed tiger who's learned not to eat his buddies, and Sid (John Leguizamo), a sloth whose mental ice tray is a couple of cubes short — are feeling left out.
Which brings us to Dimension Two: Plot. When Sid falls through a hole in the ice into a warmer, center-of-the-Earth-style world, he finds three enormous eggs and decides to use them to start a family of his own. Alas, their biological parent — a T. rex — isn't pleased, and she spirits the hatchlings and Sid down to her world, whereupon adventures ensue.
Some of those scrapes involve a swashbuckling weasel, who I'm afraid I left out in Dimension One. Which is no small oversight, because he's voiced by Simon Pegg as a cross between Errol Flynn and Johnny Depp at his Jack Sparrow-est. As the lone resident mammal in the otherwise reptilian world under the ice — he apparently fell through long ago and got acclimated — he more or less takes over the second half of the picture.
And so we arrive at Dimension Three: How does the Ice Age message — basically, "Can't we all just work past our differences and get along?" — translate to 3-D?
Well, it certainly plays out with more visual depth, though the animators don't insist on shoving things into your lap every three seconds.
Don't get me wrong: When pterodactyls fly over your shoulder, it's plenty persuasive, but the effect is becoming natural enough that I actually forgot for much of the picture that I was wearing glasses. Dimensions One and Two — characters and plot — are primary here, as they should be, technical wizardry notwithstanding.
In fact, unlike say, Monsters Vs. Aliens, which would have been nothing at all without its special-effects spectacle, this is a sweet little comedy, both family-friendly and centered on a nontraditional family, and so suitable for pretty much everyone.
Everyone, that is, who can get past the not-really-minor, probably inescapable fact that come next fall, elementary-school teachers everywhere will face classes full of kids absolutely convinced that an ice age marked the dawn of the dinosaurs, rather than the death of the dinosaurs.
They'll have seen it at the movies, after all — and in lifelike 3-D, too. 
