[postgis-devel] [PostGIS] #555: Ability to define a geometry column as Polyhedral surface

[PostGIS]

#555: Ability to define a geometry column as Polyhedral surface
---------------------+------------------------------------------------------
 Reporter:  robe     |       Owner:  colivier     
     Type:  defect   |      Status:  new          
 Priority:  medium   |   Milestone:  PostGIS 2.0.0
Component:  postgis  |     Version:  trunk        
 Keywords:           |  
---------------------+------------------------------------------------------

Comment(by colivier):

 Regina,

 A PolyhedralSurface could be 2D, 2D5 or 3D !

 2D if only X,Y,(M) defined (in this case it's really close
 to a multipolygon, except that we oblige all polygons to be connected)

 2D5 if there's also Z defined

 3D if in more each patch is connected to 2 others (and then produce a
 polyhedron, so a volume)


 Area work on 2D (even if your geometry is not only 2D)
 On SQL/MM we are supposed to implement also in addition
 ST_3DArea to deal with such a thing.

 And you're definiltly right current ST_Area don'deal with Z !

 There's no statement (AFAIK) to indicate what to do if
 the geometry is 2D5/3D and the function is 2D only
 (i.e exit on error, or silently ignore Z dimension)



 For Oracle i dunno,
 Only thing i've seen on papers is that they don't use the
 same way to describe a volume (so not the same WKT)

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/555#comment:8>
PostGIS <http://trac.osgeo.org/postgis/>
The PostGIS Trac is used for bug, enhancement & task tracking, a user and developer wiki, and a view into the subversion code repository of PostGIS project.