An Atlanta maverick who defied architects’ ethics codes by plunging into real estate development, Mr. Portman, who had no money to start with, made and lost millions of dollars cofinancing many of his own projects. From the 1980s on he designed and built hotels, retail marts and office towers in China, South Korea, Singapore, Malaysia and India — and more complexes in Europe, the Middle East and the United States.

As they proliferated in the United States, Mr. Portman’s atrium hotels, many built for the Hyatt Corporation, were widely imitated by other architects who sought to capitalize on the dizzying exhilaration (some called it terror) of patrons soaring 50 stories in a Buck Rogers glass capsule, or dining under the stars as the city moved in a circle with the galactic night. You did not even have to rent a room.

There were setbacks for the atrium concept. The 40-story Hyatt Regency Kansas City, designed by three local architects with an atrium imitating Mr. Portman’s, was the scene of a collapse of two aerial walkways in 1981 during a dance competition in the lobby. The collapse killed 114 people and injured 216 others in one of the nation’s deadliest structural failures.

By the late 1980s, with atriums in the Westin Bonaventure in Los Angeles, the Hyatt Regency in San Francisco, the Marriott Marquis in New York and dozens of others, the design was so common that some motels had what passed for atriums. Travelers were no longer impressed, and critics said Mr. Portman had repeated himself too often.