The brainless special effects summer action extravaganza reaches its 2007 apogee with Michael Bay’s mega-budget, CGI-laden, live-action translation of the mid-eighties animated TV series (and 1986 feature) about two armies of shape-shifting alien robots (Autobots—led by Optimus Prime—good, Decepticons—led by Megatron—bad) battling over the fate of the universe and bringing their war to earth, which was in turn based on a Hasbro line of action figures kids could manipulate to look like cars, trucks and other stuff. The question about Michael Bay’s “Transformers” (like the recent “TMNT”) isn’t so much whether it’s been done well as whether it should have been done at all. Because although from a purely technical perspective it’s a marvel—a well-oiled machine, awash in splashy visuals—like its bulky metallic heroes it lacks the slightest spark of humanity; the supposedly human characters possess no more personality than the robots, coming across as cartoonish stick figures that might have stepped out of a network sitcom. Fast-paced but totally vacuous, the picture comes across as the most expensive toy (and car) commercial ever made, and at nearly two and a half hours even the most proficient advertisement will eventually lose its charm.

The script concocted by Alex Kurtzman and Roberto Orci actually mingles the Transformers story with what’s essentially a teen comedy about a nerdy high-schooler, his new car and a foxy classmate. The two warring robot species are drawn to earth to retrieve a super-powerful cube called the Allspark, possession of which will apparently decide their battle. Their search focuses on young Sam Witwicky (Shia LaBeouf), whose grandfather, an Arctic explorer, discovered the device decades earlier and who’s selling online a pair of his ancestor’s glasses that apparently contains the key to its location. (The name eBay is mentioned so often that one hopes the website paid a proper product-placement fee.) One of the Autobots, Bumblebee, disguises himself as a seen-better-days yellow Camaro the kid’s father buys him in order to serve as the boy’s protector while his compatriots assemble for battle. In a sort of reversal of “Christine,” the car plays tunes on its radio vaguely appropriate to Sam’s immediate needs and otherwise helps him out with his romantic hopes re Mikaela (Megan Fox), the svelte co-ed he’s crazy over, in his tongue-tied way. Meanwhile the Decepticons try to locate Sam by tapping into the government’s secret computer files, which brings them into conflict with the U.S. army—especially a squad in Quatar led by Captain Lennox (Josh Duhamel) and Sergeant Epps (Tyrese Gibson), and the DOD and its gung-ho Secretary Keller (Jon Voight).

There are scads of other characters floating around in the mix, too—Mikaela, of course, who becomes geeky Sam’s ally; the DOD analyst (Rachael Taylor) who cracks the robot code with the help of the obligatory hipster hacker (Anthony Anderson) whose happy-go-lucky genius is designed to pander to the dork crowd in the audience; a comically stern “man in black” from a super-secret agency (John Turturro) who takes Sam into custody but eventually proves the key to the cube’s location; and Sam’s boobish mom and dad (Kevin Dunn and Julie White). Under Bay’s flashy but superficial direction, all of them—as well as Bernie Mack, doing a cameo as a used-car salesman—mug up a storm, with Voight and Turturro in particular acting like refugees from Tim Burton’s “Mars Attacks!” But the heavy lifting is definitely done by LaBeouf, who remains engaging even when trapped amid an avalanche of mechanized special-effects mayhem.

And an avalanche it truly is: these robots are constantly transforming, like huge, demented super versions of Rubik’s cube, into some new shape, and they fight over and over again, demolishing whole city blocks in the process; between the battles they stand around and jabber in lame dialogue that veers from adolescent twaddle to stentorian pronouncements. It must have taken an army of effects engineers and computer specialists (as well as the hack screenwriters and some mediocre voice talent, including Hugo Weaving as Megatron) to manage it all. But to remarkably little effect. The ’bots are a curiously boring bunch, making one long for the charm of an R2D2 or C3PO (or even Robbie the Robot). And since it’s pretty much impossible to care about what happens to them, it’s difficult to appreciate, even from a technical perspective, the elaborate sequences in which they wail away at one another like a bunch of overdeveloped trashcans. (It’s just a spiffier version of the sort of stuff that’s been done on “Power Rangers” forever.)

The ultimate problem with “Transformers” is that it has absolutely no emotional core—both the robots and the humans they interact with are pallid, and however much energy Bay pumps into the proceedings (the level enhanced by the swift-cut editing of Paul Rubell, Glen Scantlebury and Thomas A. Muldoon, as well as Steve Jablonsky’s bombastic score), it’s all likely to leave you cold in much the same way that Roland Emmerich’s “Independence Day”—another cartoonish effects extravaganza about extraterrestrial invaders unveiled for the July 4 holiday, except eleven years ago—did. It’s not impossible to make a film about outer-space visitors that strikes a human chord—Spielberg, who’s one of the executive producers here, managed the feat with both “Close Encounters of the Third Kind” and “E.T.,” and he tried (but failed) with “War of the Worlds.” But if “Encounters” and “E.T.” were for the child at heart, Bay’s exhibition of low-brow humor, empty action and special effects is for the child at mind.

Of course, this view of “Transformers” comes from someone who until recently was totally unfamiliar with the whole phenomenon. (In preparation for seeing the movie, I did watch a couple episodes of the old series, which struck me as awful as well as incomprehensible.) Perhaps those with a nostalgic affection for the show will feel differently (although some acquaintances who used to watch it disliked the picture intensely, for the changes it made as well as its general stupidity.) And young boys brought up on video games who thrive on cartoon violence will probably enjoy it. (Fanboys who’ve never outgrown their devotion, of course, will eat it up as a matter of course.)

Others, however, will probably agree that this is one silly, overblown movie, skillful but bombastic eye-candy for the adolescent-minded, with the cinematic I.Q. of your average household appliance.