NAME

       v.drape  - Converts 2D vector features to 3D by sampling of elevation raster map.

KEYWORDS

       vector, geometry, sampling, 3D

SYNOPSIS

       v.drape
       v.drape --help
       v.drape       input=name       [layer=string]        [cats=range]        [where=sql_query]
       [type=string[,string,...]]  output=name  elevation=name   [method=string]    [scale=float]
       [null_value=float]   [--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 [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 inhab >= 10000

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

       output=name [required]
           Name for output vector map

       elevation=name [required]
           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.drape  converts  2D/3D  vector  data  into 3D vector format via sampling of an elevation
       surface. Three sampling algorithms adapted  from  v.sample  were  incorporated  into  this
       module: nearest neighbor, bilinear, and cubic convultion.

       v.drape  will skip vector features outside of current computational region or where raster
       map has NULL value. It’s possible to include all  vector  features  by  specifying  height
       value  that  will  be assigned to verticles whose values can not be determined from raster
       map.

NOTES

       Additional vertices can be added to the input 2D vector map with v.split.

       The module can be used in conjunction with v.out.pov and r.out.pov to  export  a  complete
       set of vector and raster data for display in POVRAY.

EXAMPLES

       Spearfish example:
       v.drape in=roads elevation=elevation.10m method=bilinear out=roads3d
       v.info roads3d

       Create  3D  vector roads map containing only "unimproved" roads. Set road height to 1000 m
       for all parts without height information.
       v.drape input=roads type=line elevation=elevation.dem output=roads_3d \
               method=nearest scale=1.0 where=’cat=5’ layer=1 null_value=1000

   POVRAY example
       #export the vector data
       v.drape in=roads out=roads3d elevation=elevation.10m
       v.out.pov roads3d out=roads3d.pov
       #export the raster data
       r.out.pov elevation.10m tga=elevation.tga
       r.out.png landcover.30m out=landcover30m.png
       # now write a complete povray-script and launch povray

SEE ALSO

        v.extrude, v.to.3d, r.out.pov, v.in.region, v.out.pov, v.overlay, v.split, v.what.rast

AUTHORS

       Dylan Beaudette, University of California at Davis.
       Updated for GRASS 7 by Martin Landa, Czech Technical University in Prague, Czech Republic

       Last changed: $Date: 2014-11-28 17:25:40 +0100 (Fri, 28 Nov 2014) $

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       © 2003-2016 GRASS Development Team, GRASS GIS 7.0.3 Reference Manual