3D Geographic Information Systems (3D GIS) are systems for structuring and managing 3D spatial data and are capable of handling 3D geometry structures and performing onto them basic spatial analysis functionalities of a GIS. This means assigning the same importance to the <x,y,z> coordinates both in data visualization operations and data retrieving or editing ones.

The widening of the Geographic Information Systems (GIS) fields of application, led by the advances in Information and Communication Technology (ICT), has radically modified not only the tools, but also the approach to spatial information management. The first applications of GIS were oriented essentially toward digital cartography management, supporting only 2D and 2.5D representations. Starting from the late 1990s, the widespread use of ICTs has radically improved also the availability of spatial information over the internet. GIS tools became powerful instruments to perform complex analyses both on thematic and geometry content and the use of them has become essential in many areas. The increasing application of GIS to urban cartography is one of the major causes of growing interest in 3D GIS. The shift from large-scale presentations to urban and architectural representations is in fact the key to understanding the system capabilities for managing the third dimension. While 2D and 2.5D representations fulfill the needs of large-scale mapping, urban maps require the capability of handling 3D representations. Some emerging areas of interest for 3D GIS applications are: management of urban areas development, environmental monitoring, emergency management, architecture and civil engineering, geological analysis, automatic vehicle navigation, and CH documentation and management (Abdul-Rahman & Pilouk, 2008).

Surfaces can be roughly classi ed by the the dimension of the space they occupy: a 2D surface (plane) lies on in R2 while a 3D one belongs to R3. As far as nothing new, but actually there is a third kind of surfaces that occupy the 3D space, but are somehow more an extension of the 2D space rather than full 3D geometries: the 2.5D surfaces.In a Cartesian coordinate system we may think at 2.5D surfaces as those which are not self overlapping and are not vertical. More generally a 3D surface must have at least one reference plane for which the slope of the surface in one ore more points is equal or bigger than a right angle.

Original article

Costamagna, E. (2014). Geographic Information Science (GIS) 3D. In A. C. Michalos (Ed.), Encyclopedia of quality of life and well-being research (pp. 2512–2521). Dordrecht, Springer Netherlands. https://doi.org/10.1007/978-94-007-0753-5_4083

2.5D surface geometric representation