You would be able to load up the building, walk around and see how it feels when you experience it for the first time. Its a great tool for architects, designers, even marketing people as they get a feel for the space.
The demonstration is going to show Boston City Hall so I'm going to show the design process here.
All images are a work in progress and subject to copyright.
The grid structure determined by the floor plan.
Initial layout in 3DS Max