I am having some issues with a built in .net framework class (System.Data.Spatial.DbGeometry in assembly System.Data.Entity). It turns out that this class cannot parse 3D geometries when they are denoted using the correct (at least to my understanding) form.

According to Section 7.2.3 of OpenGIS Implementation Specification for Geographic information - Simple feature access - Part 1: Common architecture

The correct representation of a 3D point is: "Point Z (10 10 5)". However .Net doesn't understand the 'Z'. If I omit the 'Z' and try to parse "Point (10 10 5)", I get a 3d point.

My question is, is there such an alternative WKT-specification that allows omitting the 'Z' (same goes for measures 'M')?

  • "The nice thing about standards is there's so many to choose from." But seriously, why would there need to be an alternative standard if Microsoft didn't choose to implement the OpenGIS one correctly? – Vince Dec 6 '16 at 12:15
  • Ok I see, maybe WKT exists in different flavors (maybe ZM was added later). I havent been working very long with GIS so I was a bit surprised when I saw that I could not parse a 3D geometry that was generated using the function St_AsText(geom) in PostGis. This function will correctly generate Z/M-letters where appropriate. Without ZM, I cant see how it is possible to construct a 2D Measured linestring. – Emil G Dec 6 '16 at 12:32

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