1r.buildvrt(1)               GRASS GIS User's Manual              r.buildvrt(1)
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NAME

6       r.buildvrt   -  Build  a  VRT  (Virtual  Raster) from the list of input
7       raster maps.
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KEYWORDS

10       raster, mosaic, virtual raster
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SYNOPSIS

13       r.buildvrt
14       r.buildvrt --help
15       r.buildvrt     [input=name[,name,...]]      [file=name]     output=name
16       [title=phrase]     [--overwrite]    [--help]    [--verbose]   [--quiet]
17       [--ui]
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19   Flags:
20       --overwrite
21           Allow output files to overwrite existing files
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23       --help
24           Print usage summary
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26       --verbose
27           Verbose module output
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29       --quiet
30           Quiet module output
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32       --ui
33           Force launching GUI dialog
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35   Parameters:
36       input=name[,name,...]
37           Name of input raster files
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39       file=name
40           Input file with one raster map name per line
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42       output=name [required]
43           Name for output raster map
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45       title=phrase
46           Title for resultant raster map
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DESCRIPTION

49       r.buildvrt builds a virtual raster (VRT) that is a mosaic of  the  list
50       of  input  raster  maps.  The  purpose of such a VRT is to provide fast
51       access to small subsets of the VRT,  also  with  multiple  simultaneous
52       read requests.
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NOTES

55       r.buildvrt creates a list of raster maps that can be located in differ‐
56       ent mapsets. The output is a read-only link to the original raster maps
57       which  is  only  valid if the original raster maps remain in the origi‐
58       nally indicated mapset. A VRT can also be built from raster maps regis‐
59       tered with r.external.
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61       Reading  the  whole  VRT  is  slower than reading the equivalent single
62       raster map. Only reading small parts of the VRT provides a  performance
63       benefit.
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65       A  GRASS  virtual  raster  can  be  regarded as a simplified version of
66       GDAL’s virtual raster format.  The GRASS equivalent is simpler  because
67       issues  like  nodata,  projection,  resolution, resampling, masking are
68       already handled by native GRASS raster routines.
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EXAMPLES

71   VRT from a DEM in the North Carolina sample dataset
72       In this exercise a low resolution DEM is resampled to a high resolution
73       DEM.  This is subsequently cut into small tiles and from that a virtual
74       tile mosaik is created:
75       # set the computational region to elevation map
76       g.region raster=elev_state_500m -p
77       # enforce higher resolution
78       g.region res=50 -p
79       # resample the 500 meter DEM to 50 meter resolution
80       r.resamp.interp input=elev_state_500m output=elev_state_50m method=bilinear
81       # create tiles from resulting large 50 m elevation map
82       r.tile input=elev_state_50m output=elev_state_50m_tile_ width=1000 height=1000 overlap=0
83       # for convenience, dump list of tile names to a file
84       g.list type=raster pattern=elev_state_50m_tile_* output=tilelist.csv
85       # build a mosaik as VRT from tile list
86       r.buildvrt file=tilelist.csv output=elev_state_50m_vrt
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SEE ALSO

89        r.tile, r.patch, r.external
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91       The equivalent GDAL utility gdalbuildvrt
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AUTHOR

94       Markus Metz
95       Sponsored by mundialis
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SOURCE CODE

98       Available at: r.buildvrt source code (history)
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100       Main index | Raster index | Topics index | Keywords index  |  Graphical
101       index | Full index
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103       © 2003-2020 GRASS Development Team, GRASS GIS 7.8.5 Reference Manual
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107GRASS 7.8.5                                                      r.buildvrt(1)