So, for those of you who haven’t seen it, SFCGAL, “a C++ wrapper library around CGAL with the aim of supporting ISO 19107:2013 and OGC Simple Features Access 1.2 for 3D operations” is now an optional include in PostGIS (I believe beginning with 2.1, forgive me if I’m wrong). This was a quiet outcome of the Boston Code Sprint, after Paul Ramsey declared exact rational number representation would not make its way into PostGIS.
(I promise, that’s the only animated gif I’ll ever do, hat tip James Fee who did it for years before it was cool).
What does this mean for a typical PostGIS user? Well, so far it adds a nice suite of new 2D and 3D functions:
- ST_Extrude — Extrude a surface to a related volume
- ST_StraightSkeleton — Compute a straight skeleton from a geometry
- ST_IsPlanar — Check if a surface is or not planar
- ST_Orientation — Determine surface orientation
- ST_ForceLHR — Force LHR orientation
- ST_MinkowskiSum — Perform Minkowski sum
- ST_Tesselate — Perform surface Tesselation
- ST_Extrude is fun– this is a function for doing things like this:
ST_StraightSkeleton does in one step the first phase of what I’ve been going on about for a couple years re: Voronoi diagrams (and bypasses Voronoi altogether):
Plus more! I’ve just started exploring.
BTW, in advance of there being an SFCGAL install guide for PostGIS, a good source for info on install can be gleaned from the PostGIS Developers listserve.