Ubuntu Manpage: v.out.vtk - Converts a GRASS binary vector map to VTK ASCII output.

NAME

       v.out.vtk  - Converts a GRASS binary vector map to VTK ASCII output.

KEYWORDS

       vector, export

SYNOPSIS

       v.out.vtk
       v.out.vtk help
       v.out.vtk  [-cn]  input=name  [output=string]   [type=string[,string,...]]   [dp=integer]   [scale=float]
       [layer=integer]   [--verbose]  [--quiet]

   Flags:
       -c
           Correct the coordinates to fit the VTK-OpenGL precision

       -n
           Export numeric attribute table fields as VTK scalar variables

       --verbose
           Verbose module output

       --quiet
           Quiet module output

   Parameters:
       input=name
           Name of input vector map

       output=string
           Path to resulting VTK file

       type=string[,string,...]
           Feature type
           Options: point,kernel,centroid,line,boundary,area,face
           Default: point,kernel,centroid,line,boundary,area,face

       dp=integer
           Number of significant digits (floating point only)

       scale=float
           Scale factor for elevation
           Default: 1.0

       layer=integer
           Layer number
           Default: 1

DESCRIPTION

       v.out.vtk converts a GRASS vector map in binary format to the VTK ASCII output.

       If the output parameter is not given, the output will be send to stdout.

NOTES

The following vector types can be exported together in one VTK ascii file:
point line centroid boundary area face
Category data (cat) for the selected vector type and layer will be written as scalar data with name
"cat_{vectorname}". If no cat exists, the value will set to -1 as normal cat's are always positive. If a
vector has more categories in one layer, only the first category will be exported.
All numeric attribute fields of a given layer of the input map can be exported as scalar VTK variables
using the "-n" flag.
3d vectors are supported by default. The created VTK data always includes x, y and z coordinates (z = 0
if not a 3d vector map). Note that you can easily convert your 2d vectors into 3d vectors with v.drape.
Because of the 32bit limits of OpenGL which is used by VTK, visualisation errors may occure if the grass
region contains coordinates greater than 1.000.000 and vector coordinates with 0.01 - 0.001 meters
precisison. For this reason, the flag "-c" was added. The coordinates are transformed to smaller
coordinates (by decreasing the coordinates with the region center).
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
default region).
The GRASS vector data is converted into the polydata format of VTK:
vtk Vertices -- representing points and centroids vtk lines -- representing lines and boundaries vtk
polygons -- representing areas and faces

The VTK file can be visualized with VTK Toolkit, Paraview and MayaVi.

Attention
If areas or faces are exported, the data have to be triangulated within Paraview or MayaVi.

EXAMPLE

       Spearfish example:

       Export the soils with cats in layer 1:
       v.out.vtk input=soils type=area layer=1 output=/tmp/soils.vtk
        Export the streams with cats in layer 1:
       v.out.vtk input=streams type=line layer=1 output=/tmp/streams.vtk
        Write the archsite vtk output to stdout with cats in layer 1:
       v.out.vtk input=archsites type=point layer=1

AUTHOR

       Soeren Gebbert

       Full index

       © 2003-2013 GRASS Development Team

GRASS 6.4.3                                                                                    v.out.vtk(1grass)