v.to.3d - GRASS GIS manual

NAME

v.to.3d - Performs transformation of 2D vector features to 3D.

KEYWORDS

SYNOPSIS

v.to.3d

v.to.3d --help

v.to.3d [-rt] input=name [layer=string] [type=string[,string,...]] output=name [column=name] [height=float] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

-r: Reverse transformation; 3D vector features to 2D
-t: Do not copy attribute table
--overwrite: Allow output files to overwrite existing files
--help: Print usage summary
--verbose: Verbose module output
--quiet: Quiet module output
--ui: Force launching GUI dialog

Parameters:

input=name [required]: Name of input vector map; Or data source for direct OGR access
layer=string: 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 name.; Default: 1
type=string[,string,...]: Input feature type; Options: point, line, boundary, centroid; Default: point,line,boundary,centroid
output=name [required]: Name for output vector map
column=name: Name of attribute column used for height; Can be used for reverse transformation, to store height of points
height=float: Fixed height for 3D vector features

DESCRIPTION
NOTES
EXAMPLES
- Transform 2D vector features to 3D
- Transform 3D vector features to 2D
SEE ALSO
AUTHOR

DESCRIPTION

The v.to.3d 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 parameter.

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.

NOTES

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).

EXAMPLES

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
v.db.select map=geodetic_pts columns=cat,Z_VALUE,Z_VALUE_D

# convert 2D vector point map to 3D based on attribute
v.to.3d input=geodetic_pts out=geodetic_pts_3d column=Z_VALUE_D

Transform 3D vector features to 2D

v.to.3d -rt input=elev_lid792_bepts output=elev_lid_2d

AUTHOR

Martin Landa, Czech Technical University in Prague, Czech Republic

SOURCE CODE

Available at: v.to.3d source code (history)

Latest change: Wednesday Mar 01 21:08:00 2023 in commit: 1a96f69ccf430caa03bec8dbfc990c07c81f3164