Millie Lamoreaux and Pinky Rose, the central characters of Robert Altman's fascinating but elusive new picture, "3 Women," opening today at the K-B Cinema, seem to embody a peculiar, poignant kind of mass cultural naivete and deprivation. They're innocent, lonely, unformed young women, full of hope and ignorance.

This igorance about their own emotions, aspirations and prospects poses the greatest threat to their development as either friends or grown-up individuals. Regretably, Altman has failed to dramatize this threat and its repercussions adequately after perceiving its significance and arousing considerable interest in the personalities and fates of his characters. "3 Women" is a masterpiece-in-the-making that doesn't quite make it in the final analysis, a masterpiece that gets away.

One thinks of Millie and Pinky as girls rather than women, a peculiarity rendered at once plausible and touching by the casting and acting of Shelley Duvall and Sissy Spacek. It would be difficult to imagine a more exquisite combination for the purposes of depicting and lyricizing this account of personality formation and conflict between young women who crace acceptance and sophistication while remaining misfits and babes in the woods.

Duvall's Millie and Spacek's Pinky set up a style of housekeeping that resembles the way little girls play house. They also seem to fall into a little girl's sort of sibling relationship, with orderly, ladylike, dominating Millie playing big sister to Pinky's negligent, mischievous, submissive kid sister.

Both girls are emigrees from Texas who find employment as attendats at a Southern California spa, the Desert Springs Rehabilitation and Geriatric center. Pinky, the wide-eyed newcomer, latches onto the "experienced" Millie, whose prattle impresses her as the acme of sophistication. "You're the most perfect person I ever met," Pinky confides to Millie after succeeding in becoming her roommate and first laying eyes upon the frilly, chintzy decorative magic Millie has worked on the apartment they will share.

The audience readily perceives the truth that escapes hero-worshipping Pinky, at least at the beginning. Far from being an exemplary, enviable model of smart young femininity, Millie is a sad case, sorely deceived by the models she herself relies on - the idealizations peddled by women's magazines - and either ignored or ridiculed by the other young people she knows.

There's wonderful tragicomic potential in the idea of one deluded, socially rejected kid being mistaken for a marvel of self-assurance and popularity by an even more duluded, socially ignorant kid. One could imagine characters like Mil eiland Pinky in the plays or stories of Tennessee Williams and Carson McCullers. As a matter of fact, they have certain affinities with Williams' Blanche Dubois and McCullers' Frankie Adams. The strongest element of suspense in the film dervives from our apprehension that Millie's system of ilusions must be shattered sooner or later. The qyestions are how it should be accomplished and how the dismantling should affect both girls.

Altman sets up an intriguing and possibly devastating situation. For about 90 minutes "3 Women" seems spellbinging. Altman establishes a humorously observant perspective and a confident, fluid pace that allows the relationship of Millie and Pinky to unfold and ramify with a marvelous, steadily intensifying air of expectancy. Then at the cliactic point, when Pinky's eyes have been opened to Millie's pretenses and Millie, finding it intolerable to be pitied by her idolator, lashs out by blaming Pinky for her own social failure, Altman begins to lose his sense of direction.

Altman's intuitive way of working usually points his movies in pertinent, interesting, revelatory directions, but it may also fail to see them to a dramatically satisfying or explicable journey's end. "3 Women" is something of a miracle movie. Altman literally dreamed it into existence, and it's undreamed it into existence, and it's unlikely that any other American director could have conjured up a similar miracle as quickly or professionally. Altman may be a dreamer, but he's also a dreamer who possesses the business savvy and filmmaking discipline necessary to get a dream on the screen when it's still relatively fresh.

Ironically, the dream that inspired Altman in the first place may have betrayed him when he was faced with the obligation of resolving the relationship between Millie and Pinky. Altman's original conception had a melodramatic, Gothic ring: One woman steals another's personality, and where does this leave the victim? The movie seems to be evolving in a different - and more interesting - way. Pink's "theft" of Millie's personality evokes a mixture of comedy and pathos, because Millie herself is a confused, unformed personality, dependent on syntheic behavior to create a self-image that pleases her.

Altman appears to fall back on the Gothic conception after leaving it far behind in terms of human and psychological interest. The crucial mistake occurs after Millie precipitates a neartragedy by bolwing up at Pinky. In the aftermath Pinky undergoes a change of character from adoring, spontancous innocent to resentful, scheming slut that makes no human or dramatic sense whatever. Altman aggravates this switch by pulling another one at the denouncement, which finds Pinky even more childish and submissive than she was at the start and Millie transformed into a laughably austere symbol of barren matriarchy.

Having discovered and helped create a fresh, original set of characters and then located them in a setting that seems simultaneously concrete yet mysterious, Altman seems well on the way to glory. If he had trusted the characters more, he might have made it. Millie and Pinky take on a dramatic life of their own that Altman seems to cut short arbitrarily in the disappointing, inexplicable last reel. They become prisoners of a gimmicky preconception when one would prefer to see them evolve a human step farther and begin to act less like girls and more like women.

Despite the ridiculous aspects of their behavior, neither Millie nor Pinky seems to be a hopeless case. It may take absurd, misguided forms, but Millie's desire to enrich and beautify her life is perfectly understandable and respectable. Moreover, the chintzy nest she supervises for herself and Pinky may be vastly preferable to the settings they're come from. Their taste and judgment may be dubious, but one can't totally reject their instincts or aspirations.

It might have made a lot of difference if the third woman referred to in the title - Janice Rule as a largely symbolic figure named Willie, a pregnant, taciturn artist - had emerged fully as a character. Willie appreas to be the repository of the womanly enlightenment that has yet to dawn on the girls. Her savagely erotic murals, painted on the sides and bottoms of swimming pools, don't merely hint at violent impulses and emotional conflicts. If anything, they scream primal warnings, a message that is astutely modulated by Chuck Rosher's cinematography and Gerald Busby's discteetly ominous score, highlighted by flute solos from Micael Parloff, a 1970 graduate of Walter Johnson High in Bethesda.

It appears to be significant that Pinky is attracted to Willie's paings, which Millie considers stric weirdsville (not necessarily an sound critical opinion, by the way) also seems significant that Willie the first person to discover Pinky ILLEGIBLE) when her life hangs in the balance. ILLEGIBLE) Unfortunatley, Altman doesn't follow up on either of these clues, which leaves one to believe that Pinky might catch on to the unhappy facts of life sooner than Milie and that Willie might he rescue the girls from their ignoran.

Altman really needs to follow through here. Sissy Spacek gives Pinky an undercurrent of native and toughness even when she's [WORD ILLEGIBLE] ingenuously. The twinkle in his eyes and the impishness in her [WORD ILLEGIBLE] , mischievous gestures suggests fun loving, resilient traits that are basically sounder than the pretension she admires in Millie. Spacek seems to be preparing the way for a qualtiy of perception that Altman himself fails to give the character credit for Maybe it would have helped if he had seen "Carie" and realized the kind rapport and empathy Spacek [WORD ILLEGIBLE] about to create with a mass audience Turning Pinky into a tart for 10 or [WORD ILLEGIBLE] minutes is one of his major miscales lations.

Willie's labor is depicted as a trying matizing experience for the girls, but Altman doesn't get a dramatic grip on the nature and significance of the trauma. It appears that this episode ought to be designed to reunite and partially wise up the girls, but it's mainly a tricky horror sequence, [WORD ILLEGIBLE] fused by an even trickier, expendable dream sequence that has just gone begore and hopelessly confused by Altman's manipulation of the girls' regations, which take another drastic turn for the baffling, inscrutable worse.

It will probably be less embarrassing if Altman's notion of what Millie is supposed to represent at the concession remains a mystery. However Shelly Duvall's performance is the happiest professional revelation of the show. For the first time she appear to be acting with both range and technical facility.She has certainly never been as arresting and impassioned she is in the stretch that begins with Millie's anger at the collapse of he dinner party and culminates in the tearful remorse she feels while waiting in the hospital for news about Pinky's condition. She's come a longway from "Brewster McCloud." Altman has also brought "3 Women" long way from the dream fragmen that inspired it. If only he'd gon just one reel deeper.