A new generation of skyscrapers is about to alter the skyline of Atlanta, previously dismissed as sterile and nondescript. Even homegrown architect John Portman, whose glass towers and soaring atriums for years defined Atlanta and who in the past criticized post-modern architecture as a step backward, has given a nod to the style in his latest project, a 60-story office building planned for downtown Atlanta. Much of the excitement over the pending transformation of the capital of the New South started last fall with the opening of the 50-story IBM building. Officially called One Atlantic Center, it is a slender, post-modern tower of stone with tall arched entryways and Gothic finials, dramatically crowned by a 100-foot-high, eight-sided copper pyramid topped by a golden lantern. Rush-hour traffic on Interstate 85 slows to a cautious crawl as drivers gaze its way. At night, the lights in its crown command attention from all over town. Architecture writers have used words like ``gracious,'' ``truly wonderful,'' ``serene,'' ``imposing'' and ``glamorous'' to describe the tower. ``It certainly projects a vibrance to the rest of the world,'' said Roy Cooper, vice president for economic development with the Atlanta Chamber of Commerce. ``It's just beautiful. Everybody's just staggered by it.'' The tower is a dramatic departure from the glass boxes common in modern architecture and contrasts with the sleek look of most of the city's tallest buildings. Its influence shows up in at least three other skyscrapers going up in Atlanta, and the design of the proposed Promenade skyscraper complex was altered to complement the rose-colored IBM tower. New York architect John Burgee, whose firm designed the IBM building with design consultant Philip Johnson, won't take credit for transforming Atlanta's skyline. But he said the city's image, as defined by the way it looks, is undergoing a change. ``Atlanta has been looking for its identity,'' Burgee said in a telephone interview from his New York office. ``It's an historical city (but) its architecture and image is not strictly historical. You think of Atlanta and you think of `Gone With The Wind.' Now, there is an attempt to come up with a visual image. ``We all know Peachtree Street, but you don't think of its buildings,'' he said. ``Like in New York, the Empire State Building; Chicago, the Sears building; San Francisco, the TransAmerica building. Atlanta doesn't have that. It's moving toward that, very definitely.'' Burgee and Johnson also are behind One Ninety One Peachtree Tower, a post-modern skyscraper planned for downtown Atlanta. Another planned project grouped in the ``Son of IBM'' building spurt is the Promenade in the tree-lined, historic Midtown section, a complex of three office buildings and a hotel being developed by AT&T and the Atlanta-based Landmarks Group. When unveiled last year, it was designed with an exterior of glittering green glass. But when Promenade officials saw the excitement over the nearby IBM Tower, its architects, Thompson, Ventulett & Stainback, redrew the plans to use rose glass above rose-toned stone and topped with a gray steel spire. The most recently announced skyscraper is a downtown giant by Portman, whose imprint is already deeply felt in Atlanta, primarily through the Peachtree Center and the towering cylindrical Westin Peachtree Plaza Hotel. Portman's new building is slated to begin construction next year and, at 60 stories, will eclipse One Atlantic as the Southeast's tallest building. Unveiling the design in May, Portman said it was ``respectful of the past but, like this city, is audacious and bold and forward-looking _ the beginning of post-post-modern architecture.'' Dale Durfee, a professor of architecture at Georgia Tech, said completion of the IBM tower signaled the acceleration of a change in the look of the city that began a decade ago. ``Atlanta was pretty much plain vanilla,'' he said, ``with no development of architectural significance.'' Burgee echoed that appraisal, saying, ``It was pretty nondescript. It might be anyplace. If they took you (to Atlanta) blindfolded and took off the blindfold, you wouldn't have a clue where you are.'' Durfee said that 10 years ago, Atlanta was groping to form an identity and had no demand for the type of buildings now are going up. Today, however, companies want sophistication in their office buildings, Durfee said, and corporate sponsorship of building projects has changed the rules of skyscraper financing. Some say that all the building activity simply makes good business sense. ``Sure, there's competitive prestige. Good architecture is good business,'' said Truman Hartshorn, chairman of the geography department at Georgia State University and a specialist in urban affairs. A good-looking building, he said, ``is easier to sell to the financing people as well as the tenants.'' Hartshorn said he expects the new projects in Atlanta will bring special recognition. ``I think it's going to open some eyes,'' he said. ``We have prestige with our cultural buildings, but I don't know that our office buildings are that distinctive nationally. ``These aren't just ultra post-modern. They're classic. They're different.''