Herbert Ross' "Nijinsky," now at the Dupont Circle, degenerates decisively into stilted period evocation and confusing biographical melodrama -- but its shortcomings may have been unavoidable.

It is possible that Vaslav Nijinsky, Serge Diaghilev and the Ballets Russes are overspecialized, boobytrapped subjects to begin with, destined to bring grief to anyone who presumes to distill their time and personalities into a comprehensible scenario.

But the elusive nature of the subject didn't necessarily oblige Ross and screenwriter Hugh Wheeler to make an enigmatic hash of it.

The movie begins with a tragically evocative image of George de la Pena as Nijinsky lost in a mad trance while wearing a straitjacket -- presumably in a mental asylum. Cinematographer Douglas Slocombe, lighting this often sumptuous production with loving care, bathes de la Pena in a melancholy shaft of light from a high window. The suggestion, of course, is that we'll learn what brought this poor soul to such a pitiful state.

After a meteoric 10-year career, during which he restored the male classical dancer to esteem, became a sensation among continental cognoscenti and experimented with choreographic ideas to new compositions by Debussy and Stravinsky, Nijinsky began suffering mental breakdowns. Diagnosed as schizophrenic, he spent about the last 30 years of his life in and out of institutions.

The movie chronicle begins in 1912 in Budapest during a tour of the ballet company successfully organized by Diaghilev only a few years earlier. Nijinsky was its principal ornament. The opening scenes introduce Diaghilev (Alan Bates) as impresario and as Nijinsky's mentor and lover. They also introduce Leslie Browne, who made her film debut two years ago as the aspiring young ballerina in Ross' "The Turning Point," as Romola de Pulzsky, the young Hungarian aristocrat who became infatuated with Nijinsky as a performer and later became his wife.

When a scene of Bates being tenderly solicitous to his young protege (and remarking, "I'm always telling you women have their uses") is soon followed by the sight of Browne smoldering with desire on first witnessing de la Pena leap through an open window in "Specter of the Rose," we conclude that the groundwork for a romantic triangle is being prepared. And while I suppose it was, Ross and Wheeler end up constructing a tastefully furnished edifice that fails to evoke much passion -- homosexual, heterosexual or artistic -- and then crumbles into a heap at the climax.

Although the character of Romola is introduced promptly, the movie is perhaps 100 minutes old before she begins posing a romantic threat to Diaghilev. Up to that point the film is preoccupied with depicting his theatrical manipulations and recreating snippets of the old Ballets Russes repertory -- all looking like period pieces.

The most effective dramatic motif in the show is Diaghilev's conflict with Makhail Fokine (Jeremy Irons), who was eased out as the company's choreographer in order to enhance Diaghilev's plans for Nijinsky.

As the dancer, de la Pena is a vivid boyish presence on screen, though not up to the more extravagant histrionic demands ultimately made upon him. His appearance and stylized postures remind you of the animated, miniature creatures made by Ray Harryhausen for the Sinbad movies and suggest what Nijinsky's animistic dancing may have been like.

Picturesque as some of this re-creation is, a sense of the Diaghilev company as experimenters fails to take hold, perhaps because time has absorbed those innovations.

While recalling the ballet lore, the filmmakers suddenly remembered Romola and that potential triangle. With insufficient time to rationalize her presence, they switch from leisurely theatrical legend to desperate romantic tragedy.

Romola and Nijinsky finally have their shipboard romance while the company heads for a South American tour and Diaghilev remains in Europe. The young lovers marry. Diaghilev gets the bad news and dismisses Nijinsky, who begins acting crazy. Romola curses herself for making a terrible mistake. Nijinsky heads around the bend, and Romola resolves to care for him after appealing for help to Diaghilev, who ruefully declines and informs her, "Love isn't eternal, my dear -- it has its own time."

After taking their sweet time, the filmmakers seem to realize they don't have much left and make a ludicrous dash for the exits. Although Diaghilev was indeed stung by Nijinsky's marriage and fired him instantly (only to rehire him three years later), the idea that this conflict immediately drove the artist into madness is far-fetched, to put it gently.

The idea of Nijinsky regretting either his marriage to Romola or betrayal of Diaghilev might be developed into devastating emotional stuff. But neither attachment looks profound enough here to justify all the torment at the climax.

The cause of Nijinsky's plunge into schizophrenia was never isolated, although he was examined or studied by the most prominent analysts, Freud and Jung included. The war may have been as responsible as anything else, since it disrupted Nijinsky's work for a considerable period while he, Romola and their daughter were interned in Hungary and then Austria. At any rate, he did not begin declining after his honeymoon.

The tone of homosexual worldliness chosen to characterize Diaghilev and his financial angle Baron de Gounsberg (transformed from a hetrosexual into the limp figure played by Alan Badel) gets to be a pervasive drag. While Bates seems to be specializing in a brawny embodiment of all the campiest Claude Rains roles, Badel specializes in enervated Clifton Webb. Talk about dueling banjos!

Although it's clear that these characters are supposed to exude sophistication, they exude it so mercilessly and stuffily that their presence grows tiresome. Not unlike "Nijinsky" itself, I'm afraid.