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   [ti‐
16       tle=phrase]   [--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]
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18   Flags:
19       --overwrite
20           Allow output files to overwrite existing files
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22       --help
23           Print usage summary
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25       --verbose
26           Verbose module output
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28       --quiet
29           Quiet module output
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31       --ui
32           Force launching GUI dialog
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34   Parameters:
35       input=name[,name,...]
36           Name of input raster files
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38       file=name
39           Input file with one raster map name per line
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41       output=name [required]
42           Name for output raster map
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44       title=phrase
45           Title for resultant raster map
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DESCRIPTION

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

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

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

88        r.tile, r.patch, r.external
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90       The equivalent GDAL utility gdalbuildvrt
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AUTHOR

93       Markus Metz
94       Sponsored by mundialis
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SOURCE CODE

97       Available at: r.buildvrt source code (history)
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99       Accessed: Saturday Jan 21 21:14:26 2023
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101       Main  index  | Raster index | Topics index | Keywords index | Graphical
102       index | Full index
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104       © 2003-2023 GRASS Development Team, GRASS GIS 8.2.1 Reference Manual
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108GRASS 8.2.1                                                      r.buildvrt(1)