As an actor portraying the inner turmoil of Jackson Pollock -- the revolutionary abstractionist known for his splatter-and-drip painting style -- Ed Harris gives a commanding, potent performance in "Pollock" that is a torrential mix of the artist's chaotic talent and his more chaotic psyche.

As a director depicting Jackson Pollock's world, Ed Harris (yes, he did double-duty on this film) captures with vivid, lively authenticity both the astute yet pretentious buzz of the 1940s Manhattan art scene and his subject's tumultuous personal life, marked by hard drinking and a stormy long-term affair with fellow painter Lee Krasner (Marcia Gay Harden).

Together Ed Harris the actor and Ed Harris the director create an imposing, invigorating cinematic biography fueled by its subject's stubborn, manic energy and his strangely uncommunicative charisma.

The film opens in 1949 with close-up of Pollock's paint-caked hands signing an autograph on the issue of Life magazine that featured his work. At this moment, he is on a pedestal in the art world and from his clear, placid gaze he seems to be content and in control. The film later returns to this scene to demonstrate that it was only a momentary calm in the storm of Pollock's life.

In the second scene the movie rolls back the clock, showing Pollock in a depressed and drunken rage over his jealous admiration of Picasso. The juxtaposition of these two episodes sets the erratic mood for the film, which begins in earnest in 1941 when he meets artist Krasner, his lover and professional partner who helped launch his reputation and celebrity.

Harden matches Harris's powerful performance, bringing to life Krasner's exponential frustration as she willingly sets aside her own career to cater to the often unappreciative and occasionally insulting Pollock. The most impassioned scenes in the film are the hurtful, rage-filled fights between these two.

Harris does a startlingly affecting job of drawing the viewer into Pollock's realm, sharing with us the sensation of his artistic epiphanies and the evolution of his provocative, avant-garde style. The first time he lays a canvas on the floor of his studio, giving him better control over his broad, heavy strokes with house paint brushes, you feel Pollock's sudden sensation of unexpected freedom. The first time paint accidentally drips on the horizontal canvas as he pauses to think, you get goose-pimply and feel like shouting out "Eureka!"

The picture makes it clear that Pollock's work is not as random as it seems (Harris's performance is never more intense or credible than when he's bent over a painting in progress). However, the audience is expected to take it as read that this art is pure genius. Harris doesn't delve deeply enough into the thoughts behind Pollock's paintings. Instead he just throws into the dialogue an occasional random pronouncement like, "You've done it, Pollock! You've cracked it wide open!" -- whatever that means.

At times the movie falls back on the conventional, too, like when it establishes Pollock's affair with Ruth Kligman (the under-rated Jennifer Connelly), the only survivor of the drunk driving crash that killed the painter in 1956. In one scene they have a contrived post-coital conversation that begins, "If you could be anybody in the history of the world, who would it be?" And the story has a wholly inadequate epilogue once the inevitable crash has occurred in the last reel.

Nonetheless, Harris's directorial debut is a sturdy, compelling accomplishment from its dramatic imagery to its spectacularly dynamic, ironically upbeat score to its cast full of memorable performances. Watch for Amy Madigan stealing scenes as eccentric power-patron Peggy Guggenheim, Bud Cort as the extremely self-satisfied curator of her modern art shows, and Val Kilmer in a cameo as Willem DeKooning.