Three-Dimensional Data Models

Three-dimensional (3D) data models focus on portraying the third dimension of physical objects and phenomena through the integration of semantic, geometric, and spatial data relationships. Fundamentally, this is a perspective different from the static, 2D or bird's-eye perspective on the world in traditional spatial data modeling. There are two approaches to modeling the third dimension in geographic information systems (GIS): (1) quasi-3D data modeling and (2) true 3D data modeling.

In the first approach of quasi-3D data modeling, a geographic phenomenon can be constructed as a surface in which a given geographic location is defined by a set of x and y coordinates, and a single value z can be assigned to this location. The value z can be elevation above sea level or any other ...