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v.extrude(1)		    GRASS GIS User's Manual		  v.extrude(1)

NAME
       v.extrude   -  Extrudes flat vector features to 3D vector features with
       defined height.
       Optionally the height can be derived from sampling of elevation	raster
       map.

KEYWORDS
       vector, geometry, sampling, 3D

SYNOPSIS
       v.extrude
       v.extrude --help
       v.extrude     [-t]     input=name      [layer=string]	  [cats=range]
       [where=sql_query]	 [type=string[,string,...]]	   output=name
       [zshift=float]	   [height=float]     [height_column=name]     [eleva-
       tion=name]     [method=string]	  [scale=float]	    [null_value=float]
       [--overwrite]  [--help]	[--verbose]  [--quiet]	[--ui]

   Flags:
       -t
	   Trace elevation

       --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=nameA [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

       cats=range
	   Category values
	   Example: 1,3,7-9,13

       where=sql_query
	   WHERE conditions of SQL statement without 'where' keyword
	   Example: income < 1000 and population >= 10000

       type=string[,string,...]
	   Input feature type
	   Options: point, line, area
	   Default: point,line,area

       output=nameA [required]
	   Name	for output vector map

       zshift=float
	   Shifting value for z	coordinates
	   Default: 0

       height=float
	   Fixed height	for 3D vector features

       height_column=name
	   Name	of attribute column with feature height

       elevation=name
	   Elevation raster map	for height extraction

       method=string
	   Sampling interpolation method
	   Options: nearest, bilinear, bicubic
	   Default: nearest
	   nearest: Nearest-neighbor interpolation
	   bilinear: Bilinear interpolation
	   bicubic: Bicubic interpolation

       scale=float
	   Scale factor	sampled	raster values
	   Default: 1.0

       null_value=float
	   Height for sampled raster NULL values

DESCRIPTION
       v.extrude  creates  faces, kernels or 3D	lines based on input 2D	vector
       features. Points	are converted to 3D vertical lines, lines to faces and
       areas to	volumes	(composition of	closed set of faces and	kernel).

       If  elevation parameter is used then 3D vector features follow the ele-
       vation model by using individual	elevation  values  for	the  vertices.
       Height  for  vertices  is  interpolated from elevation raster map using
       given interpolation method.

NOTES
       v.extrude extrudes vector features which	means  that  points  are  con-
       verted  to  vertical lines. Lines and area boundaries are extruded to a
       set of faces, each segment defines one face. Area centroids are written
       as  kernels. Area as a composition of boundaries	and centroid is	stored
       as a closed set of faces	and kernel which define	a volume.

       For conversion of 2D points or lines to	3D  can	 be  used  v.to.3d  or
       v.drape.	 In opposite to	v.extrude, these modules do not	extrude	vector
       features, they defines z-coordinate for the features from given parame-
       ters  or	by sampling elevation raster map values. It means that no fea-
       ture type conversion is applied,	points remain still points in the out-
       put vector map. Same applies for	the lines.

       v.extrude  modifies  only  features geometry. Feature categories	remain
       untouched and attribute data is copied from input  vector  map  to  the
       output.

       By default, all features	(including features without category) from in-
       put vector map are processed (layer=-1).	Feature	selection can  be  ap-
       plied by	layer, cats or where parameter.

EXAMPLES
   3D houses with fixed	height
       v.extrude input=houses output=houses3D height=5 type=area

   3D houses with individual height
       v.extrude input=houses output=houses3D elevation=dem height_column=height type=area

   Convert 2D points to	3D vertical lines with fixed height
       v.extrude input=geodetic_pts output=points3D height=200 type=point

SEE ALSO
	v.transform, v.drape, v.to.3d

	wxGUI 3D viewer

AUTHORS
       Jachym Cepicky,
       Updated	for GRASS 7 by Martin Landa, FBK-irst, Italy and Czech Techni-
       cal University in Prague, Czech Republic

SOURCE CODE
       Available at: v.extrude source code (history)

       Main index | Vector index | Topics index	| Keywords index  |  Graphical
       index | Full index

       A(C) 2003-2020 GRASS Development	Team, GRASS GIS	7.8.3 Reference	Manual

GRASS 7.8.3							  v.extrude(1)

NAME | KEYWORDS | SYNOPSIS | DESCRIPTION | NOTES | EXAMPLES | SEE ALSO | AUTHORS | SOURCE CODE

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