raster3dintro(1grass)						Grass User's Manual					     raster3dintro(1grass)

3D Raster data (voxel) in GRASS GIS
   3D Raster (voxel) import
       The  module  r3.in.ascii  supports  generic  x,y,z  import.  Alternatively, voxels can be generated from 3D point vector data (v.to.rast3).
       Always the full map is imported.  Volumes can also be created based on 2D elevation map(s) and value raster map(s) (r.to.rast3elev). Alter-
       natively, a volume can be composed of several 2D raster map slices which are merged into one 3D raster volume map (r.to.rast3).

   Voxel region settings and 3D MASK
       GRASS  3D  raster  map processing is always performed in the current 3D region settings (see g.region, -p3 flags), i.e.	the current region
       extent, vertical extent and current 3D resolution are used.  If the 3D resolution differs from that of the input raster map(s),	on-the-fly
       resampling  is  performed (nearest neighbor resampling).  If this is not desired, the input map(s) has/have to be reinterpolated beforehand
       with one of the dedicated modules.  Masks can be set (r3.mask).

   Voxel operations
       Powerful 3D map algebra is implemented in r3.mapcalc.

   Voxel conversion to vector or 2D raster maps
       3D vector point data can be converted to a GRASS 3D raster map (v.to.rast3).  Layers from a 3D raster map can be converted to a	2D  raster
       map (r3.to.rast).  Cross sectional 2D raster map can be extracted from 3D raster map based on a 2D elevation map (r3.cross.rast).

   Voxel statistics
       Volume statistics can be calculated with r3.stats and r3.univar.

   Voxel interpolation
       From 3D vector points, GRASS 3D raster maps can be interpolated (v.vol.rst). Results are volumes, or 2D raster maps can be also extracted.

   Voxel export
       GRASS 3D raster maps can be exported to VTK (r3.out.vtk).  VTK files can be visualized with the VTK Toolkit, Paraview and MayaVi.  GRASS 2D
       raster maps can be exported to VTK with r.out.vtk, GRASS vector maps can be exported to VTK with v.out.vtk.

       Alternatively, GRASS 3D raster maps can be imported and exported from/to Vis5D (r3.out.v5d).  Note that Vis5D is limited in the	number	of
       supported voxels.

       Finally, export to 3D ASCII is also available (r3.out.ascii).

   See also
       Introduction to GRASS raster map processing

       full index

       (C) 2008-2011 GRASS Development Team

GRASS 6.4.2														     raster3dintro(1grass)