Mmm ... The Simpsons Movie!

WHILE FANCY computer animation has dominated movies since "Toy Story," its crude, two-dimensional cousin has, in "The Simpsons," retained a loving home on TV.

"The Simpsons" succeeds on the tube (like "SpongeBob SquarePants") expressly because of its comparatively simplistic animation - the style is a perfect match for the show's roster of belching, bingeing characters. I'm not sure an army of Pixar technicians and supercomputers could improve upon the gloriously low brow of Homer Simpson (I think it's behind his bugged-out eyes).

All of this, of course, belies its high-brow authorship. It's an astute show that's functioned for two decades as the nation's resident class clown, with an uncanny knack of knowing which things need to be mocked, and precisely how.

Matt Groening, James Brooks, Harry Shearer, et al. have mastered the verse of television comedy - stanzas of inspired comedy designed to play between commercials, forming a rhyming whole.

Can you take an act like that to the big screen? "South Park" proved that you can, and come up with a movie that's even funnier than the series, something that stands apart as a work in itself.

"The Simpsons Movie" turns out to be a more qualified success. Fans will enjoy it, but it will likely be a footnote in the larger story of the show's phenomenal run on television.

"TSM" tries to fill the dimensions of the screen by building several stories around an environmental theme - pollutants are fouling the local lake. Do-gooder Lisa organizes an Al Gore-like campaign to raise consciousness about the water, and it's a huge success - townsfolk agree to stop polluting it, and she gets a cute Irish/activist/singer boyfriend (Milhouse is beyond bummed).

All is well as long as all agree not to dump another foul thing in the lake - an embargo broken by...

D'oh.

Homer, you see, has adopted a pet pig, causing suckling rivalry in Bart, and the problem of how to dispose of pig poop.

Environmental chaos ensues, and the Simpson family frays. An agreeably silly road movie develops as Homer tries to find a way to save his family and Springfield, by now quarantined by President Schwarzenegger and the corporate huckster who controls the Environmental Protection Agency.

The movie is true to the wit and quicksilver personality of the television show - there's an obvious green message, and little wisecracky digs at those who deny that climate change is linked to harmful emissions.

At the same time, "TSM" displays an understanding of the insufferableness of earnest advocacy. When Lisa makes her save-the-lake presentation to the town, it's titled "An Irritating Truth."

And the laughs-first, lessons-later tone of the show is preserved. In fact, the creative team's natural instinct to be true to itself may be the movie's handicap. "The Simpsons" thrives on off-handedness and subtle jabs - it doesn't have the ferocious, Big Subject aggressiveness of "South Park," a style that lends itself to the movies.

It has Homer and Bart, though, still as made for each other as doughnuts and beer.