What made architect John Portman's buildings stand out?

The Westin Bonaventure hotel in downtown LA has been featured in several movies and TV shows. Its big open atrium and glass elevators have been the fictional site of chases, disasters, and presidential assassination attempts. They’ve been features of hotels and office buildings all over the world. The architect of the Bonaventure, John C. Portman, died Friday in Atlanta. He was 93.