[postgis-users] geometry types
pramsey at cleverelephant.ca
Tue May 20 18:21:15 PDT 2008
On Tue, May 20, 2008 at 3:06 PM, Karina Guardado <kguardado at gmail.com> wrote:
> 1.from the 1.2.0 release of PostGIS there is support for "curve" /types/,
> and initial support for the ISO SQL/MM suite of spatial database functions
Yes, and you'll see some sparse documentation on these. There is not
full support of these types by all the functions, in fact very few of
the functions will support them.
> 2.(from the list)We made a patch to add such new geometries to PostGIS.
> It implements TIN and POLYHEDRALSURFACE as described in
> OGC SFS1.2 standard.
> These geometries are specific MULTIPOLYGON that
> describe 3D surfaces and 3D volumes.
> Currently, we got the following functions to work for 3D geometries:
> - asEwkb
> - asEwkt
> - asGml
> - asSvg (2D output only)
> - asX3d.
> This last function enables exporting 3D geometries to the X3D format.
> I also provide a patch for GEOS to implement the isValid function
> for TIN and POLYHEDRALSURFACE. It checks if feature faces
> are well connected and well oriented.
> So after reading this I feel confused if this geometry types are really
> supported or not and I think it is not clear still for me, I would like to
> know if there is an official documentation but updated with the last
> geometry types supported by Postgis.
This patch exists, as you found it on the list, but it has not been
applied. I have some grave misaprehensions about the whole idea of
modeling large structures like TIN as a single object. However, I am
open to being forced into it by the Will of the People.
Frank is right about LinearRing not being instantiable. I'd have to
check and see but I believe there is no such thing as an instantiable
Curve, just CurveString. At least, a single curve isn't very useful
as an object.
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