NAME

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

KEYWORDS

       raster, mosaic, virtual raster

SYNOPSIS

       r.buildvrt
       r.buildvrt --help
       r.buildvrt     [input=name[,name,...]]      [file=name]     output=name     [title=phrase]
       [--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]

   Flags:
       --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[,name,...]
           Name of input raster files

       file=name
           Input file with one raster map name per line

       output=name [required]
           Name for output raster map

       title=phrase
           Title for resultant raster map

DESCRIPTION

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

NOTES

       r.buildvrt creates a list of raster maps that can be located  in  different  mapsets.  The
       output is a read-only link to the original raster maps which is only valid if the original
       raster maps remain in the originally indicated mapset. A VRT can also be built from raster
       maps registered with r.external.

       Reading  the  whole  VRT  is  slower  than  reading the equivalent single raster map. Only
       reading small parts of the VRT provides a performance benefit.

       A GRASS virtual raster can be regarded as a simplified version of  GDAL’s  virtual  raster
       format.   The  GRASS  equivalent  is  simpler  because  issues  like  nodata,  projection,
       resolution, resampling, masking are already handled by native GRASS raster routines.

EXAMPLES

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

SEE ALSO

        r.tile, r.patch, r.external

       The equivalent GDAL utility gdalbuildvrt

AUTHOR

       Markus Metz
       Sponsored by mundialis

SOURCE CODE

       Available at: r.buildvrt source code (history)

       Accessed: Thursday Aug 01 11:29:49 2024

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       © 2003-2024 GRASS Development Team, GRASS GIS 8.4.0 Reference Manual