3D Raster data (voxel) in GRASS GIS

       GRASS GIS is one of the few GIS software packages with volume data support.  Here data are stored as a 3D
       raster  with  a unit volume called a voxel (volume pixel). Voxels are designed to support representations
       of trivariate continuous fields.

   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). Alternatively, 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.  A 3D groundwater flow model is implemented in
       r3.gwflow.

   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

       © 2008-2012 GRASS Development Team

GRASS 6.4.3                                                                                raster3dintro(1grass)