[Qgis-developer] [Qgis-user] Using/visualizing 3D data (Z values)

[Noli Sicad]

On 9/26/12, gene <martin.laloux at gmail.com> wrote:
> The problem is that Shapely is based on GEOS and GEOS isn't a 3D library at
> all. *The z of the geometries are not considered during any spatial
> operations but you can use matplotlib to represent the 3D geometry*

Spatialite 4.0 has 3D and it is using GEOS library for geometry. I
wonder where Spatialite gets its 3D?

~~~~

POINT	2D, XY
AddGeometryColumn('tbl', 'geom', 4326, 'POINT', 2);
AddGeometryColumn('tbl', 'geom', 4326, 'POINT', 'XY')
AddGeometryColumn('tbl', 'geom', 4326, 'POINT');

3D, XYZ	
AddGeometryColumn('tbl', 'geom', 4326, 'POINT', 3);
AddGeometryColumn('tbl', 'geom', 4326, 'POINT', 'XYZ')
AddGeometryColumn('tbl', 'geom', 4326, 'POINTZ')
AddGeometryColumn('tbl', 'geom', 4326, 'POINTZ', 3);
AddGeometryColumn('tbl', 'geom', 4326, 'POINTZ', 'XYZ');

2D + measure, XYM	
AddGeometryColumn('tbl', 'geom', 4326, 'POINT', 'XYM');
AddGeometryColumn('tbl', 'geom', 4326, 'POINTM');
AddGeometryColumn('tbl', 'geom', 4326, 'POINTM', 'XYM');

3D + measure, XYZM	
AddGeometryColumn('tbl', 'geom', 4326, 'POINT', 4);
AddGeometryColumn('tbl', 'geom', 4326, 'POINT', 'XYZM')
AddGeometryColumn('tbl', 'geom', 4326, 'POINTZM');
AddGeometryColumn('tbl', 'geom', 4326, 'POINTZM', 4);
AddGeometryColumn('tbl', 'geom', 4326, 'POINTZM', 'XYZM');

https://www.gaia-gis.it/fossil/libspatialite/wiki?name=switching-to-4.0

Noli