
NAME
v.drape - Converts vector map to 3D by sampling of elevation raster map.
KEYWORDS
vector, geometry, sampling
SYNOPSIS
v.drape
v.drape help
v.drape input=name [type=string[,string,...]] [rast=name] [scale=float] [method=string] output=name [--overwrite] [--verbose] [--quiet]
Flags:
- --overwrite
- Allow output files to overwrite existing files
- --verbose
- Verbose module output
- --quiet
- Quiet module output
Parameters:
- input=name
- Name of input vector map
- type=string[,string,...]
- Type
- Feature type(s)
- Options: point,centroid,line,boundary,face,kernel
- Default: point,centroid,line,boundary,face,kernel
- rast=name
- Elevation raster map for height extraction
- scale=float
- Scale sampled raster values
- Default: 1.0
- method=string
- Sampling method
- Options: nearest,bilinear,cubic
- Default: nearest
- nearest: nearest neighbor
- bilinear: bilinear interpolation
- cubic: cubic convolution interpolation
- output=name
- Name for output vector map
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.
NOTES
Please run beforehand
and make sure that the extent of the elevation raster is at least as
big as the vector to convert.
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.
EXAMPLE
Spearfish example:
g.region -p vect=roads align=elevation.10m
v.drape in=roads rast=elevation.10m method=bilinear out=roads3d
v.info roads3d
POVRAY EXAMPLE
#setup the region
g.region vect=roads align=elevation.10m -p
#export the vector data
v.drape in=roads out=roads3d rast=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
ERROR MESSAGES
If the following error message appears
WARNING: Current region does not include the entire input vector map
WARNING: Reading raster map request for row 466 is outside region
ERROR: Problem reading raster map
it indicates that the vector map is spatially larger than the current
region settings. To avoid this problem, set region from the input
vector map and re-run v.drape.
If the following error message appears
WARNING: Elevation raster map does not cover the entire area of the input vector map.
it indicates that the vector map is spatially larger than the raster map.
To avoid this problem, the vector map needs to be clipped to the raster
map extent, for example:
g.region rast=demname
v.in.region clipbox
v.overlay ain=clipbox bin=vectmap out=vectmap_clipped op=and
v.drape vectmap_clipped out=vectdrape rast=demname
Then v.drape should perform the draping.
SEE ALSO
r.out.pov,
v.in.region,
v.out.pov,
v.overlay,
v.split,
v.what.rast,
v.extrude
AUTHOR
Dylan Beaudette, University of California at Davis.
Last changed: $Date: 2008-01-20 14:38:27 -0800 (Sun, 20 Jan 2008) $
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