Abstract: An interactive visualization tool is provided that enables its users to build, modify and interactively view three-dimensional simulation models of a particular geographical space over time. The interactive visualization tool is adapted to receive a user specified time and subsequently render the geographical space in accordance with the specified time. To represent a geographical space over time, the interactive tool employs a scene definition data structure. The scene definition data structure is comprised of a hierarchical tree structure having a plurality of nodes, such that each node represents a physical structure in the geographical space. Each node is further defined to include a time period during which the physical structure exists in the geographical space and link data to the corresponding three-dimensional model data for the physical structure.