While the somewhat-familiar story of Helen of Troy is an epic about love and war, the spectacular-looking new film version is mostly just about war, with love merely lurking in the fringes. This is a huge movie, bearing the DNA of films like “Titanic,” “Lord of the Rings” and “Jason and the Argonauts,” with huge sets and huge characters, and it’s nearly as enthralling as the glorious epics it emulates.

Combining Homer’s “Iliad” with screenwriter David Benioff’s (“25th Hour”) Hollywood-infused imagination, the film is set in approximately 1200 B.C., at a time when Greece had conquered most of the immediate area. King Menelaus (Brendan Gleeson) of Sparta is eager to stop all the fighting and have peace in his realm, unaware that his wife Helen (Diane Kruger) is having an affair with young Paris (Orlando Bloom), prince of Troy. When the Trojans head home after a visit to the mainland, she goes with them, infuriating Menelaus and destroying his vision of a peaceful retirement: As Bugs Bunny used to say, of course you know THIS means war.

This development is precisely what Menelaus’ brother Agamemnon (Brian Cox), leader of the Greek army, was waiting for. Agamemnon is a warlord of the old school, a swaggering braggart who won’t be happy until he has fought and defeated every last city. And so far Troy has been the only holdout, its city walls impenetrable and its army formidable. Now, at last, is an excuse to attack them, and to do it with the full force of an outraged Greek army behind him.

He calls upon Achilles (Brad Pitt), an impudent soldier who commands a little army known as the Myrmidons and who is easily Greece’s most cunning and agile warrior. Achilles and Agamemnon have a mutual respect and dislike for one another, both appalled at the other’s self-serving nature and both intent on fighting for HIMSELF and no one else. Achilles, it is rumored, cannot be killed, though when a messenger boy asks him if it’s true, he sardonically replies, “Why would I be putting on my armor?”

And so the war is afoot, the Greeks enjoying victory on the shores of Troy but being repelled once they reach the walls of the city itself; you are probably aware that a wooden horse is eventually brought into play. Director Wolfgang Petersen, adept at heart-pounding action (“The Perfect Storm,” “Air Force One,” “In the Line of Fire”), guides the battle scenes with a sure hand and a sharp eye for exciting visuals. James Horner’s brassy, portentous musical score adds adrenaline, and the cinematography of Roger Pratt captures the vastness of the landscape and its inhabitants. This is, as I said, a big movie.

Trojan king Priam is played by Peter O’Toole, one of those “great actors” who has not appeared in a great movie for so long that he might as well be an ancient Greek himself for as much as a modern audience knows about him. His performance here won’t get him an eighth Oscar nomination, but it is appropriately majestic.

He’s out-acted by several others, including Eric Bana as Hector (Paris’ more circumspect brother) and Brendan Gleeson as the enraged Menelaus. And they’re all out-acted by Brian Cox, who as Agamemnon lights up the screen with his borderline hammy, deliciously bemused delivery. The way he snarls, threatens and postures is the stuff Oscar dreams are made of.

Unfortunately, Brad Pitt doesn’t quite cut it as Achilles. I’m a fan of his work generally, but he’s out of his league here. He’s not as theatrical and grand as his co-stars; he’s a little too pretty, and a little too shallow.

In all, the film lacks the emotional gravity of the great epics, and not just because of Pitt. The love affair that ostensibly started the war is barely addressed, and the relationships in general — between fathers, brothers, husbands, friends — don’t feel as real as in some better films. In “Troy,” the war itself is so all-encompassing that the people in it are almost lost — a tragic fact of real-life war, and a disappointing one in movie wars, I suppose. But on the other hand, it looks and sounds fantastic, and people get to say things like, “Before my time is done, I will look down on your corpse and smile,” and it’s hard not to enjoy a movie like that.

B+ (2 hrs., 45 min.; R, a little bit of profanity, some partial nudity, a little sexuality, a lot of violence (some of it graphic).)