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  - Converts 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]   [scale=float]   [layer=integer]   [--verbose]  [--quiet]
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17   Flags:
18       -c
19           Correct the coordinates to fit the VTK-OpenGL precision
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21       --verbose
22           Verbose module output
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24       --quiet
25           Quiet module output
26
27   Parameters:
28       input=name
29           Name of input vector map
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31       output=string
32           Path to resulting VTK file
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34       type=string[,string,...]
35           Type
36           Feature type(s)
37           Options: point,kernel,centroid,line,boundary,area,face
38           Default: point,kernel,centroid,line,boundary,area,face
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40       dp=integer
41           Number of significant digits (floating point only)
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43       scale=float
44           Scale factor for elevation
45           Default: 1.0
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47       layer=integer
48           Layer number
49           Default: 1
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DESCRIPTION

52       v.out.vtk converts a GRASS vector map in binary format to the VTK ASCII
53       output.
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55       If  the  output parameter is not given, the output will be send to std‐
56       out.
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NOTES

59       The following vector types can be exported together in  one  VTK  ascii
60       file:
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62                     point
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64                     line
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66                     centroid
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68                     boundary
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70                     area
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72                     face
73       Category  data  (cat)  for  the  selected vector type and layer will be
74       written as scalar data with name "cat_{vectorname}". If no cat  exists,
75       the  value  will  set  to -1 as normal cat's are always positive.  If a
76       vector has more categories in one layer, only the first  category  will
77       be exported.
78       3d  vectors  are  supported  by  default.  The  created VTK data always
79       includes x, y and z coordinates (z = 0 if not a 3d vector  map).   Note
80       that  you  can  easily  convert  your  2d  vectors into 3d vectors with
81       v.drape.
82       Because of the 32bit limits of OpenGL which is used by VTK,  visualisa‐
83       tion errors may occure if the grass region contains coordinates greater
84       than 1.000.000 and vector coordinates with 0.01 - 0.001 meters precisi‐
85       son.  For  this  reason,  the  flag "-c" was added. The coordinates are
86       transformed to smaller coordinates (by decreasing the coordinates  with
87       the region center).
88       If  the  "-c"  flag  is used and the data should be visualised together
89       with other data exported via *.out.vtk modules, be sure the  "-c"  flag
90       was  also set in these modules.  But this will only work with data from
91       the SAME location (The reference point for the coordinates  transforma‐
92       tion is based on the default region).
93       The GRASS vector data is converted into the polydata format of VTK:
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95                     vtk Vertices -- representing points and centroids
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97                     vtk lines -- representing lines and boundaries
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99                     vtk polygons -- representing areas and faces
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101       The VTK file can be visualized with VTK Toolkit, Paraview and MayaVi.
102
103   Attention
104       If areas or faces are exported, the data have to be triangulated within
105       Paraview or MayaVi.
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EXAMPLE

108       Spearfish example:
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110       Export the soils with cats in layer 1:
111       v.out.vtk input=soils type=area layer=1 output=/tmp/soils.vtk
112        Export the streams with cats in layer 1:
113       v.out.vtk input=streams type=line layer=1 output=/tmp/streams.vtk
114        Write the archsite vtk output to stdout with cats in layer 1:
115       v.out.vtk input=archsites type=point layer=1
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AUTHOR

125       Soeren Gebbert
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127       Full index
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129       © 2003-2008 GRASS Development Team
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133GRASS 6.3.0                                                       v.out.vtk(1)