NAME

       r.out.vrml  - Export a raster map to the Virtual Reality Modeling Language (VRML)

KEYWORDS

       raster, export, VRML

SYNOPSIS

       r.out.vrml
       r.out.vrml help
       r.out.vrml elev=string  [color=string]   [exag=float]  output=string  [--verbose]  [--quiet]

   Parameters:
       elev=string
           Name of elevation map

       color=string
           Name of color file

       exag=float
           Vertical exaggeration
           Default: 1.0

       output=string
           Name for new 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

       Last changed: $Date: 2011-11-08 03:29:50 -0800 (Tue, 08 Nov 2011) $

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       © 2003-2013 GRASS Development Team

GRASS 6.4.3                                                                                   r.out.vrml(1grass)