Contrary to popular perception, the “Terminator” legacy is not about filmmaker James Cameron. It’s not about actress Linda Hamilton, and it’s certainly not about fallen star Edward Furlong.

It’s all about Arnold Schwarzenegger.

“Terminator 3: Rise of the Machines” proves that when you throw the bulky Austrian into his most enduring screen role — and have a $175 million budget to play around with — the rest of the flick’s specifics don’t matter that much.

As the lone castmate to have appeared in all three films, the iconic Arnold is simply awesome in “T-3.” Whether volleying between automatic weapons, being thrown through buildings or delivering deadpan lines of dialogue, he has a way of infusing a cybernetic organism with “personality.”

It helps that the movie is not just a quick cash-in sequel like some of its blonde, angelic contemporaries. This is one entertaining piece of blockbuster craftsmanship. Indeed, the sci-fi effort has more sustained action than “The Hulk” and “The Matrix Reloaded” combined.

But more importantly, this third entry seems to fit with “The Terminator” and “Terminator 2: Judgment Day” as a logical companion piece. The sequel expands on the nature of fate that the previous pictures explored so well, culminating in a rather bold third act where “saving the day” takes on a more unconventional meaning.

The plot picks up a decade after “Judgment Day” ended.

Kristanna Loken, left, battles Arnold Schwarzenegger in the sequel Terminator

John Connor (Nick Stahl taking over for Furlong) is a drifter who “can feel the weight of the future bearing down on me.” Despite no family and no ties to society, he still manages to be targeted by an assassin sent back in time to prevent him from leading a human revolt against earth’s mechanized oppressors. This time the enemy is the T-X (Kristanna Loken), an icy “Terminatrix” who features onboard weapons and the ability to remote control other machines.

Of course Arnold returns as the outmoded but efficient T-100 who helps protect Connor and his hostage/companion Kate (Claire Danes). Like the other films, this muscular model makes his arrival through the time portal in the nude. Only instead of immediately trouncing some victim for his clothes, he wanders into a desert bar on ladies night, and they mistake him for one of the evening’s entertainers.

“Terminator 3” certainly delivers its share of visual delights, both comical and spectacular. The digital effects aren’t quite as revolutionary as those unveiled in the 1991 sequel. (Remember how startling the “liquid metal” look was when it debuted?) But the conventional action scenes staged by “U-571” director Jonathan Mostow — chases, fights, shoot-outs, explosions — are as good as anything that will make it to the screen this summer. In fact, one gloriously over-the-top pursuit involving a fire truck and a mobile construction crane results in more vehicular mayhem than found at the Battle of the Bulge.

Nick Stahl, best known for playing the doomed college kid of “In the Bedroom” and the virulent title character in “Bully,” does a decent job with the role of Connor. He doesn’t exactly set the screen on fire, but he’s at least comfortable as the lead.

A noticeably more mature-looking Danes has a little less ease making the transition from dramatic turns in films such as “The Hours” into big-budget, popcorn fare. Part of this clunkiness can be due to how little time her character is given to go from confused kidnap victim to let’s-save-the-world heroine.

Then there’s Arnold.

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The 55-year-old star desperately needed a hit after such dreadful misfires as “End of Days” and “Collateral Damage.” He was no doubt hopeful for a superior cinematic finale before the next step of his career ushers him into the political arena.

One of his most quoted lines from 1984’s “The Terminator” was the infamous “I’ll be back.” The phrase has gone beyond just being a familiar sound bite and has truly burned its way into the pop culture consciousness.

Funny enough, Arnold really is back. Sci-fi and action movie fans can be grateful.