NAME
r.out.vrml - Exports a raster map to the Virtual Reality Modeling Language (VRML).
KEYWORDS
raster,
export,
output,
VRML
SYNOPSIS
r.out.vrml
r.out.vrml --help
r.out.vrml elevation=name [color=name] [exaggeration=float] output=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
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 majority 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.
VRML is not well suited for large geometries 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.
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
Currently the region is transformed to a unit size, so real geographic
location is lost. Side effects when working in a lat-lon project are
that besides general distortion due to projection, a very small
exaggeration factor (on order of .001) must be used to compensate for
vertical units expected to be the same as map units.
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 interaction.
- Degradation of the raster to produce TINs for improved
performance.
Bill Brown, US Army Construction Engineering Research Laboratory
SOURCE CODE
Available at:
r.out.vrml source code
(history)
Latest change: Wednesday Nov 27 22:53:26 2024 in commit: 3b5486c0463a7103ab2109e28bf860fe34539868
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© 2003-2024
GRASS Development Team,
GRASS GIS 8.5.0dev Reference Manual