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]
output=
name
[
method=
string] [
scale=
float]
[
where=
sql_query] [
layer=
integer]
[
null_value=
float] [--
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,...]
-
Feature type
Options: point,centroid,line,boundary,face,kernel
Default: point,centroid,line,boundary,face,kernel
- rast=name
-
Elevation raster map for height extraction
- output=name
-
Name for output vector map
- method=string
-
Sampling method
Options: nearest,bilinear,cubic
Default: nearest
nearest: nearest neighbor
bilinear: bilinear interpolation
cubic: cubic convolution interpolation
- scale=float
-
Scale sampled raster values
Default: 1.0
- where=sql_query
-
WHERE conditions of SQL statement without 'where' keyword
Example: income = 10000
- layer=integer
-
Layer number
Layer is only used for WHERE SQL statement
Default: 1
- null_value=float
-
Vector Z value for unknown height
Will set Z to this value, if value from raster map can not be read
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 rast=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 rast=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 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
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: 2011-11-08 12:29:50 +0100 (Tue, 08 Nov 2011) $
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