Provided by: grass-doc_6.4.3-3_all bug


       r.out.vtk  - Converts raster maps into the VTK-Ascii format


       raster, export


       r.out.vtk help
       r.out.vtk    [-pstvoc]    input=name[,name,...]     [output=string]     [elevation=string]
       [null=float]               [elevation2d=float]               [rgbmaps=string[,string,...]]
       [vectormaps=string[,string,...]]      [elevscale=float]      [dp=integer]      [--verbose]

           Create VTK point data instead of VTK cell data (if no elevation map is given)

           Use structured grid for elevation (not recommended)

           Use polydata-trianglestrips for elevation grid creation

           Use polydata-vertices for elevation grid creation (to use with vtkDelauny2D)

           Scale factor effects the origin (if no elevation map is given)

           Correct the coordinates to fit the VTK-OpenGL precision

           Verbose module output

           Quiet module output

           Name of input raster map(s)

           Name for VTK-ASCII output file

           Elevation raster map

           Value to represent no data cell
           Default: -10.0

           Elevation (if no elevation map is specified)
           Default: 0.0

           Three (r,g,b) raster maps to create rgb values [redmap,greenmap,bluemap]

           Three (x,y,z) raster maps to create vector values [xmap,ymap,zmap]

           Scale factor for elevation
           Default: 1.0

           Number of significant digits (floating point only)
           Options: 0-20
           Default: 12


       Outputs raster maps in VTK-ASCII format. Map's are  valid  raster  map's  in  the  current
       mapset.   output  is  the  name  of an VTK-ASCII file which will be written in the current
       working directory.  If output is not  specified  then  stdout  is  used.   The  module  is
       sensitive to region settings (set with g.region).

       Elevation,  scaling,  point/celldata, vector and RGB Data are supported.  If the map is in
       LL projection, the elevation values will automatically scaled to degrees. It  is  supposed
       that  the  elevation  values  are  provided  in  meters.  If the elevation values are in a
       different unit than meters, use the scale parameter to convert the units.

       If no elevation map is given, the user can set the hight of the map by one  value.   Point
       or  cell  data  are  available.  Also  scaling is supported for this elevation value.  The
       elevation value must be provided in meters.

       The RGB input requires three raster maps: red, green, blue  - in  this  order.   The  maps
       must have values between 0 and 255, otherwise you will get lots of warnings and the values
       are set to 0.  More than one RGB dataset (3 maps) is not supported.

       The vector input requires three raster maps: x, y, z -- defining the vector coordinates  -
       in this order.  More than one vector dataset (3 maps) is not supported.


       This filter generates:

                     structured points with celldata or pointdata if no elevationfile is given

                     structured  grid  (not  recommendet)  with  pointdata if an elevationfile is

                     polydataset with pointdata if an elevationfile is given (default)
       and puts this in a simple VTK-ASCII file. Nor XML or binary output are  supported.  It  is
       possible  to  choose  more  then  one raster map to be written to the VTK-ASCII file. Each
       cell-/pointdata is named like the raster map it represents.  You can visualize  this  file
       with  the  VTK  Toolkit, Paraview and MayaVi which are based on VTK.  If you have a raster
       map with partly no data, use the threshold filter in paraview to visualize the valid data.
       Just  filter  all data which is greater/lesser than the chosen null value in the VTK-ASCII
       If elevation map is chosen, a polygonal grid is created  with  quads,  but  the  user  can
       choose also triangle strips or vertices.  These dataformats a documented at VTK Toolkit.

       If  the  "-c"  flag  is  used  and  the data should be visualised together with other data
       exported via *.out.vtk modules, be sure the "-c" flag was also set in these modules.   But
       this  will  only  work  with  data  from  the  SAME  location (The reference point for the
       coordinates transformation is based on the center point of the default region).

   Difference between point- and celldata
       r.out.vtk can export raster cells with different representations.

                     pointdata -- the cells/values are represented by the  center  of  the  cell.
                     Instead  of cells, points are created. Each point can hold different values,
                     but the user can only visualize one value at a time.  These  points  can  be
                     connected in different ways.

                     celldata  --  is  only provided if no elevation map is given.  The cells are
                     created with the same hight and width  as  in  GRASS.  Each  cell  can  hold
                     different values, but the user can only visualize one value at a time.


   Simple Spearfish example

       # set region
       g.region n=4926970 s=4914857 w=591583 e=607793 res=50 -p
       # export the data
       r.out.vtk input=elevation.10m,slope,aspect elevation=elevation.10m output=/tmp/out.vtk
       # visualize in Paraview or other VTK viewer:
       paraview --data=/tmp/out.vtk

   Spearfish example with RGB data

       #set the region
       g.region n=4926990 s=4914840 w=591570 e=607800 res=30 -p
       # using to create RGB data to get a satellite coverage layers=global_mosaic mapserver= \
       # export the data to VTK
       r.out.vtk,, \
                 elevation=elevation.10m output=/tmp/out.vtk
       # visualize in Paraview or other VTK viewer:
       paraview --data=/tmp/out.vtk
        Paraview RGB visualization notes
       To achieve proper RGB overlay:

                      In Paraview, click "Apply"

                      Select the "Display" tab and choose "Color by" to switch from input scalars
                     to rgb scalars

                      Disable the "Map Scalars" check button in the display tab to avoid the  use
                     of a lookup table


        r3.out.vtk, r.out.ascii, g.region
       GRASS and Paraview Wiki page


       Soeren Gebbert

       Last changed: $Date: 2013-02-15 14:04:18 -0800 (Fri, 15 Feb 2013) $

       Full index

       © 2003-2013 GRASS Development Team