Using ST_Extrude to extrude building footprints

PostGIS 2.1 brought a lot of really cool additional functionality to PostGIS. Operation on PostGIS raster types are among the more important improvements that come with PostGIS 2.1. A quieter and equally potent game changer was the addition of the SFCGAL library as an optional extension to PostGIS. According to the website http://sfcgal.org/, SFCGAL is a C++ wrapper library around CGAL with the aim of supporting ISO 19107:2013 and OGC Simple Features Access 1.2 for 3D operations.

From a practical standpoint, what does this mean? It means that PostGIS is moving toward a fully functional 3D environment, with representation of the geometries themselves and the operations on those 3D geometries. More information is available at http://postgis.net/docs/reference.html#reference_sfcgal.

This and several other recipes will assume that you have a version of PostGIS installed with SFCGAL compiled and enabled. To do so enables the following functions:

• ST_Extrude...