Realistically representing our three-dimensional world has been the
subject of many (philosophical) discussions since ancient times. While
the recognition of the globular shape of the Earth goes back to
Pythagoras' statements of the sixth century B. C., the two-dimensional,
circular depiction of the Earth's surface has remained prevailing and
also dominated the art of painting until the late Middle Ages. Given the
immature technological means, objects on the Earth's surface were often
represented in academic and technical disciplines by two-dimensional
cross-sections oriented along combinations of three mutually
perpendicular directions. As soon as computer science evolved,
scientists have steadily been improving the three-dimensional
representation of the Earth and developed techniques to analyze the many
natural processes and phenomena taking part on its surface. Both
computer aided design (CAD) and geographical information systems (GIS)
have been developed in parallel during the last three decades. While the
former concentrates more on the detailed design of geometric models of
object shapes, the latter emphasizes the topological relationships
between geographical objects and analysis of spatial patterns.
Nonetheless, this distinction has become increasingly blurred and both
approaches have been integrated into commercial software packages. In
recent years, an active line of inquiry has emerged along the junctures
of CAD and GIS, viz. 3D geoinformation science. Studies along this line
have recently made significant inroads in terms of 3D modeling and data
acquisition.
