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

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 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.

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
       exaggeration factor (on order of .001) must be used to compensate for vertical 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 interaction.

           •   Degradation of the raster to produce TINs for improved performance.

AUTHOR

       Bill Brown, US Army Construction Engineering Research Laboratory

SOURCE CODE

       Available at: r.out.vrml source code (history)

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       © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual