.TH r.buildvrt 1grass "" "GRASS 7.6.0" "Grass User's Manual" .SH NAME \fI\fBr.buildvrt\fR\fR \- Build a VRT (Virtual Raster) from the list of input raster maps. .SH KEYWORDS raster, mosaic, virtual raster .SH SYNOPSIS \fBr.buildvrt\fR .br \fBr.buildvrt \-\-help\fR .br \fBr.buildvrt\fR [\fBinput\fR=\fIname\fR[,\fIname\fR,...]] [\fBfile\fR=\fIname\fR] \fBoutput\fR=\fIname\fR [\fBtitle\fR=\fIphrase\fR] [\-\-\fBoverwrite\fR] [\-\-\fBhelp\fR] [\-\-\fBverbose\fR] [\-\-\fBquiet\fR] [\-\-\fBui\fR] .SS Flags: .IP "\fB\-\-overwrite\fR" 4m .br Allow output files to overwrite existing files .IP "\fB\-\-help\fR" 4m .br Print usage summary .IP "\fB\-\-verbose\fR" 4m .br Verbose module output .IP "\fB\-\-quiet\fR" 4m .br Quiet module output .IP "\fB\-\-ui\fR" 4m .br Force launching GUI dialog .SS Parameters: .IP "\fBinput\fR=\fIname[,\fIname\fR,...]\fR" 4m .br Name of input raster files .IP "\fBfile\fR=\fIname\fR" 4m .br Input file with one raster map name per line .IP "\fBoutput\fR=\fIname\fR \fB[required]\fR" 4m .br Name for output raster map .IP "\fBtitle\fR=\fIphrase\fR" 4m .br Title for resultant raster map .SH DESCRIPTION \fIr.buildvrt\fR 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. .SH NOTES \fIr.buildvrt\fR 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 \fIr.external\fR. .PP Reading the whole VRT is slower than reading the equivalent single raster map. Only reading small parts of the VRT provides a performance benefit. .PP A GRASS virtual raster can be regarded as a simplified version of GDAL\(cqs virtual raster format. The GRASS equivalent is simpler because issues like nodata, projection, resolution, resampling, masking are already handled by native GRASS raster routines. .SH EXAMPLES .SS VRT from a DEM in the North Carolina sample dataset .br .nf \fC # set the region g.region raster=elev_state_500m \-p # higher resolution g.region res=50 \-p # resample the DEM to 50 meter r.resamp.interp input=elev_state_500m output=elev_state_50m method=bilinear # create tiles r.tile input=elev_state_50m output=elev_state_50m_tile_ width=1000 height=1000 overlap=0 # dump list of tiles to a file g.list type=raster pattern=elev_state_50m_tile_* > tilelist # build a vrt r.buildvrt file=tilelist output=elev_state_50m_vrt \fR .fi .SH SEE ALSO \fI r.tile, r.patch \fR .PP The equivalent GDAL utility \fI gdalbuildvrt \fR .SH AUTHOR Markus Metz .PP \fILast changed: $Date: 2018\-12\-26 17:29:08 +0100 (Wed, 26 Dec 2018) $\fR .SH SOURCE CODE .PP Available at: r.buildvrt source code (history) .PP Main index | Raster index | Topics index | Keywords index | Graphical index | Full index .PP © 2003\-2019 GRASS Development Team, GRASS GIS 7.6.0 Reference Manual