r.out.vrml(1grass) GRASS GIS User's Manual r.out.vrml(1grass)
NAME
r.out.vrml - Exports a raster map to the Virtual Reality Modeling Lan-
guage (VRML).
KEYWORDS
raster, export, output, VRML
SYNOPSIS
r.out.vrml
r.out.vrml --help
r.out.vrml elevation=name [color=name] [exaggeration=float] out-
put=name [--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:
elevation=name [required]
Name of input elevation raster map
color=name
Name of input color map
exaggeration=float
Vertical exaggeration
Default: 1.0
output=name [required]
Name for output VRML file
DESCRIPTION
This module exports a GRASS raster map to the Virtual Reality Modeling
Language (VRML) format for 3D visualization.
This version only outputs raster maps in VRML 1.0 format. The newer
VRML 2.0 format will be more efficient for geographic applications, as
it introduces an "ElevationGrid" node so that only the elevation points
will have to be written instead of the whole geometry. The vast major-
ity of VRML viewers currently only support VRML 1.0. If the extension
"wrl" (world) is not present in the he output parameter, it will be
added.
WARNING
VRML is not well suited for large geometrys which can result from even
a small geographic region. Most viewers seem to bog down with more
than 12,000 polygons, depending on your hardware & specific viewer.
Each grid cell results in two polygons, so a reasonable size region
would be something less than about 75x75. For improved performance and
smaller file size, leave off a color map. Since VRML is ascii text,
gzip works very well to significantly compress file size.
NOTE
This is a preliminary release of "r.out.vrml". For further information
about VRML and available viewers for various platforms, see:
VRML Virtual Reality Modeling Language
BUGS:
Currently the region is transformed to a unit size, so real geographic
location is lost. Side effects when working in a lat-lon location are
that besides general distortion due to projection, a very small exag-
geration factor (on order of .001) must be used to compensate for ver-
tical units expected to be the same as map units.
TODO
Update to the more modern GeoVRML format, or probably better the next
generation X3D format. See also the Xj3D project.
Future plans for this module are to allow draping of sites objects and
vector maps and using the new sites format available in floating point
GRASS to embed WWW links into site objects. It will also be upgraded to
support VRML 2.0 and will allow entering multiple preset "views" using
the existing GRASS 3d_view file format.
Other possible additions:
• Allow animation of elevation, color, or sites based on user in-
teraction.
• Degradation of the raster to produce TINs for improved perfor-
mance.
AUTHOR
Bill Brown, US Army Construction Engineering Research Laboratory
SOURCE CODE
Available at: r.out.vrml source code (history)
Accessed: unknown
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GRASS 7.8.7 r.out.vrml(1grass)
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