v.out.vtk(1)

1v.out.vtk(1)                  Grass User's Manual                 v.out.vtk(1)
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NAME

6       v.out.vtk  - Convert a GRASS binary vector map to VTK ASCII output
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KEYWORDS

9       vector
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SYNOPSIS

12       v.out.vtk
13       v.out.vtk help
14       v.out.vtk [-c] input=name  [output=string]   [type=string[,string,...]]
15       [dp=integer]   [layer=integer]
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17   Flags:
18       -c  Correct the coordinates to fit the VTK-OpenGL precision
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20   Parameters:
21       input=name
22           Name of input vector map
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24       output=string
25           Path to resulting VTK file.
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27       type=string[,string,...]
28           Type     Options:     point,kernel,centroid,line,boundary,area,face
29           Default: point,kernel,centroid,line,boundary,area,face
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31       dp=integer
32           Number of significant digits (floating point only)
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34       layer=integer
35           Layer number Default: 1
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DESCRIPTION

38       v.out.vtk converts a GRASS vector map in binary format to the VTK ASCII
39       output.
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41       If the output parameter is not given, the output will be send  to  std‐
42       out.
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NOTES

45       The  following  vector  types can be exported together in one VTK ascii
46       file:
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48                     point
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50                     line
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52                     centroid
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54                     boundary
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56                     area
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58                     face
59       Category data (cat) for the selected vector  type  and  layer  will  be
60       written  as scalar data with name "cat_{vectorname}". If no cat exists,
61       the value will set to -1 as normal cat's are  always  positive.   If  a
62       vector  has  more categories in one layer, only the first category will
63       be exported.
64       3d vectors are supported  by  default.  The  created  VTK  data  always
65       includes  x,  y and z coordinates (z = 0 if not a 3d vector map).  Note
66       that you can easily convert  your  2d  vectors  into  3d  vectors  with
67       v.drape.
68       Because  of the 32bit limits of OpenGL which is used by VTK, visualisa‐
69       tion errors may occure if the grass region contains coordinates greater
70       than 1.000.000 and vector coordinates with 0.01 - 0.001 meters precisi‐
71       son. For this reason, the flag "-c"  was  added.  The  coordinates  are
72       transformed  to smaller coordinates (by decreasing the coordinates with
73       the region center).
74       If the "-c" flag is used and the data  should  be  visualised  together
75       with  other  data exported via *.out.vtk modules, be sure the "-c" flag
76       was also set in these modules.  But this will only work with data  from
77       the  SAME location (The reference point for the coordinates transforma‐
78       tion is based on the default region).
79       The GRASS vector data is converted into the polydata format of VTK:
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81                     vtk Vertices -- representing points and centroids
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83                     vtk lines -- representing lines and boundaries
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85                     vtk polygons -- representing areas and faces
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87       The VTK file can be visualized with VTK Toolkit, Paraview and MayaVi.
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89   Attention
90       If areas or faces are exported, the data have to be triangulated within
91       Paraview or MayaVi.
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EXAMPLE

94       Spearfish example:
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96       Export the soils with cats in layer 1:
97       v.out.vtk input=soils type=area layer=1 output=/tmp/soils.vtk
98        Export the streams with cats in layer 1:
99       v.out.vtk input=streams type=line layer=1 output=/tmp/streams.vtk
100        Write the archsite vtk output to stdout with cats in layer 1:
101       v.out.vtk input=archsites type=point layer=1
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AUTHOR

111       Soeren Gebbert
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113       Full index
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117GRASS 6.2.2                                                       v.out.vtk(1)