1v.out.vtk(1) GRASS GIS User's Manual v.out.vtk(1)
2
6 v.out.vtk - Converts a vector map to VTK ASCII output.
7
9 vector, export, output, VTK
10
12 v.out.vtk
13 v.out.vtk --help
14 v.out.vtk [-cn] input=name [layer=string] [output=name]
15 [type=string[,string,...]] [precision=integer] [zscale=float]
16 [--overwrite] [--help] [--verbose] [--quiet] [--ui]
17 Flags:
19 -c
20 Correct the coordinates to fit the VTK-OpenGL precision
21 -n
23 Export numeric attribute table fields as VTK scalar variables
24 --overwrite
26 Allow output files to overwrite existing files
27 --help
29 Print usage summary
30 --verbose
32 Verbose module output
33 --quiet
35 Quiet module output
36 --ui
38 Force launching GUI dialog
39 Parameters:
41 input=name [required]
42 Name of input vector map
43 Or data source for direct OGR access
44 layer=string
46 Layer number or name
47 Vector features can have category values in different layers. This
48 number determines which layer to use. When used with direct OGR
49 access this is the layer name.
50 Default: 1
51 output=name
53 Name for output VTK file
54 type=string[,string,...]
56 Input feature type
57 Options: point, kernel, centroid, line, boundary, area, face
58 Default: point,kernel,centroid,line,boundary,area,face
59 precision=integer
61 Number of significant digits (floating point only)
62 zscale=float
64 Scale factor for elevation
65 Default: 1.0
66
68 v.out.vtk converts a GRASS vector map in binary format to the VTK ASCII
69 output.
70 If the output parameter is not given, the output will be send to std‐
72 out.
73
75 The following vector types can be exported together in one VTK ascii
76 file:
77 · point
79 · line
81 · centroid
83 · boundary
85 · area
87 · face
89 Category data (cat) for the selected vector type and layer will be
90 written as scalar data with name "cat_{vectorname}". If no cat exists,
91 the value will set to -1 as normal cat’s are always positive. If a
92 vector has more categories in one layer, only the first category will
93 be exported.
94 3d vectors are supported by default. The created VTK data always
95 includes x, y and z coordinates (z = 0 if not a 3d vector map). Note
96 that you can easily convert your 2d vectors into 3d vectors with
97 v.drape.
98 Because of the 32bit limits of OpenGL which is used by VTK, visualisa‐
99 tion errors may occur if the grass region contains coordinates greater
100 than 1.000.000 and vector coordinates with 0.01 - 0.001 meters precisi‐
101 son. For this reason, the flag "-c" was added. The coordinates are
102 transformed to smaller coordinates (by decreasing the coordinates with
103 the region center).
104 If the "-c" flag is used and the data should be visualised together
105 with other data exported via *.out.vtk modules, be sure the "-c" flag
106 was also set in these modules. But this will only work with data from
107 the SAME location (The reference point for the coordinates transforma‐
108 tion is based on the default region).
109 The GRASS vector data is converted into the polydata format of VTK:
110 · vtk Vertices -- representing points and centroids
112 · vtk lines -- representing lines and boundaries
114 · vtk polygons -- representing areas and faces
116 The VTK file can be visualized with VTK Toolkit, Paraview and MayaVi.
118 Attention
120 If areas or faces are exported, the data have to be triangulated within
121 Paraview or MayaVi.
122
124 Spearfish example:
125 Export the soils with cats in layer 1:
127 v.out.vtk input=soils type=area layer=1 output=/tmp/soils.vtk
128 Export the streams with cats in layer 1:
129 v.out.vtk input=streams type=line layer=1 output=/tmp/streams.vtk
130 Write the archsite vtk output to stdout with cats in layer 1:
131 v.out.vtk input=archsites type=point layer=1
132
134 v.out.ascii
135 r.out.vtk
136 r3.out.vtk
137
140 Soeren Gebbert
141
143 Available at: v.out.vtk source code (history)
144 Main index | Vector index | Topics index | Keywords index | Graphical
146 index | Full index
147 © 2003-2020 GRASS Development Team, GRASS GIS 7.8.5 Reference Manual
149GRASS 7.8.5 v.out.vtk(1)