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NAME  - Performs transformation of 2D vector features to 3D.


       vector, geometry, 3D

SYNOPSIS --help   [-rt]   input=name    [layer=string]    [type=string[,string,...]]   output=name
       [column=name]   [height=float]   [--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]

           Reverse transformation; 3D vector features to 2D

           Do not copy attribute table

           Allow output files to overwrite existing files

           Print usage summary

           Verbose module output

           Quiet module output

           Force launching GUI dialog

       input=name [required]
           Name of input vector map
           Or data source for direct OGR access

           Layer number or name (’-1’ for all layers)
           A single vector map  can  be  connected  to  multiple  database  tables.  This  number
           determines  which  table  to  use.  When used with direct OGR access this is the layer
           Default: 1

           Input feature type
           Options: point, line, boundary, centroid
           Default: point,line,boundary,centroid

       output=name [required]
           Name for output vector map

           Name of attribute column used for height
           Can be used for reverse transformation, to store height of points

           Fixed height for 3D vector features


       The module is used to transform 2D vector features to 3D. Height (z-coordinate) of
       3D  vector  features  can  be  specified  by  height parameter as fixed value or by column

       Flag -r enables to perform reverse transformation, i.e., transform  3D  vector  to  2D  by
       omitting z-coordinate. Height of input 3D features can be optionally stored in column.


       When  transforming  2D  vector  features  to  3D  based  on attribute, all NULL values are
       silently converted to height 0.0.

       Reverse transformation is possible for points and lines.  In case of  lines,  the  reverse
       transformation  should be used only when all vertices of a line have the same z-coordinate
       (for example contours).


   Transform 2D vector features to 3D
       # convert z-values from string to double
       v.db.addcolumn map=geodetic_pts columns="Z_VALUE_D double precision"
       v.db.update map=geodetic_pts column=Z_VALUE_D qcolumn=Z_VALUE map=geodetic_pts columns=cat,Z_VALUE,Z_VALUE_D
       # convert 2D vector point map to 3D based on attribute input=geodetic_pts out=geodetic_pts_3d column=Z_VALUE_D

   Transform 3D vector features to 2D -rt input=elev_lid792_bepts output=elev_lid_2d


        v.transform, v.extrude, v.drape


       Martin Landa, Czech Technical University in Prague, Czech Republic

       Last changed: $Date: 2015-06-17 04:29:17 +0200 (Wed, 17 Jun 2015) $


       Available at: source code (history)

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