Improving WKT compatibility with applications that do not follow the OpenGIS Transformations Service standard

Digi3D.NET creates WKT strings compatible with the standard OpenGis Coordinate Transformation Service, and that standard dictates that if a system is three-dimensional (which is how Digi3D.NET works) it must create reference systems or purely 3D as the Geographics 3D or compounds in which there are two parts: one horizontal and another vertical.

In the case of composite systems it is legal that both the horizontal component and the vertical can be local (unknown), so if in Digi3D.NET you create a coordinate reference system in which you know the horizontal part (for example WGS84 / UTM Zone 30N) and do not know the vertical, the program will create a composite system of the type WGS84 / UTM Zone 30N + local vertical.

This is very good for programs that follow the standard, but it drives crazy programs that do not follow it or that are not 3D, so to improve compatibility with those programs, we have added an option in Digi3D.NET that will allow us to configure it so that in the event that the user creates a 3D system in which the vertical system is unknown, when creating .PRJ files with WKT strings, they are created as pure 2D systems. If the vertical system is not local or unknown, even if you have this option enabled, the program will create a 3D string.

You can activate this functionality in the menu option Tools/Settings/Coordinate reference systems/Work with systems 2D (horizontal) if the vertical is unknown.