As a director, Mario Van Peebles made the feisty crack-war melodrama ''New Jack City,'' followed by a couple of strenuous misfires (''Panther,'' ''Posse''). As an actor, he has often come across as a genial pretty boy. Whether behind the camera or in front of it, he has always remained a bit undefined, but his career is now brought into lightning focus with the audaciously entertaining Baadasssss!, which he cowrote, directed, and stars in. The actor-filmmaker sports a hip '70s mustache, a series of ghetto-fabulous hats, and an attitude of electric, hungry-eyed defiance to portray his father, Melvin Van Peebles, during the making of ''Sweet Sweetback's Baadasssss Song'' (1971), a piece of low-budget nihilist folklore that changed the face of American films.
Melvin Van Peebles was one of the first black directors to be ushered through the gates of Hollywood, but in 1970 he withdrew from a potentially successful studio career. Instead, he chose to put his reputation, his finances, maybe even his sanity on the line to make ''Sweetback,'' a furious and garishly gripping explosion of black consciousness. Van Peebles wanted to expose all the things that white Hollywood was too terrified to touch: the sexual bravado of a black street operator, the brutality of bigoted white cops, the righteous rage unleashed when Sweetback -- played by Melvin himself as an inner-city hustler with a touch of Native Son's Bigger Thomas -- retaliates against their violence with equal violence. Shot in 19 days using a nonunion cast, ''Sweetback'' was an exploitation film made with crowd-pleasing sass and sleaze, yet also with the Burn, baby, burn! fervor of a Malcolm X manifesto.
It didn't matter that the movie wasn't particularly well told (the hero had all of six lines); what counted was that it existed in the first place. The real meaning of ''Sweetback'' was thus encoded in the logistics of how Van Peebles got it made, and ''Baadasssss!,'' which is based on Melvin's book about the creation of the film, details and celebrates the frantic, egomaniacal, so-reckless-it's-funny heroism of his crusade. After tossing off the script in an alcohol-juiced creative binge, he meets with a series of amusingly disreputable financial backers and can go ahead with filming only by duping the union reps into thinking that he's shooting a porno film. (It's not much of a charade, considering that his crew makes the film team in ''Boogie Nights'' look like they're toiling for Spielberg.) And that's nothing compared to the negotiations Van Peebles has to go through to cast his 13-year-old son, Mario (yes, that Mario, played here by Khleo Thomas), in the opening scene, which explicitly depicts the young Sweetback losing his virginity.
Perhaps no movie about the making of a movie has ever demonstrated so graphically that a filmmaker is really a politician, a hustler, and an artist, in that order. ''Sweetback'' does, of course, get made -- with a little help from Bill Cosby (T.K. Carter), who swoops in as a secret financial angel, and also a car bombing that brings the arrival of a real fire truck, which beats a staged rescue every time. Yet the battle isn't over. The most inspiring section of ''Baadasssss!'' may be its final act, in which the entire future of black cinema appears to hinge on the film's tenuous premiere at a single Detroit grind house. Did it really happen like that? Not entirely, but the beauty of ''Baadasssss!'' is the way Mario Van Peebles salutes his father's truth by coaxing it into legend.