1v.extrude(1) Grass User's Manual v.extrude(1)
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6 v.extrude - Extrudes flat vector features to 3D vector features with
7 defined height.
8 Optionally the height can be derived from sampling of elevation raster
9 map.
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12 vector, geometry, sampling, 3D
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15 v.extrude
16 v.extrude --help
17 v.extrude [-t] input=name [layer=string] [cats=range]
18 [where=sql_query] [type=string[,string,...]] output=name
19 [zshift=float] [height=float] [height_column=name] [eleva‐
20 tion=name] [method=string] [scale=float] [null_value=float]
21 [--overwrite] [--help] [--verbose] [--quiet] [--ui]
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23 Flags:
24 -t
25 Trace elevation
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27 --overwrite
28 Allow output files to overwrite existing files
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30 --help
31 Print usage summary
32
33 --verbose
34 Verbose module output
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36 --quiet
37 Quiet module output
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39 --ui
40 Force launching GUI dialog
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42 Parameters:
43 input=name [required]
44 Name of input vector map
45 Or data source for direct OGR access
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47 layer=string
48 Layer number or name (’-1’ for all layers)
49 A single vector map can be connected to multiple database tables.
50 This number determines which table to use. When used with direct
51 OGR access this is the layer name.
52 Default: -1
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54 cats=range
55 Category values
56 Example: 1,3,7-9,13
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58 where=sql_query
59 WHERE conditions of SQL statement without ’where’ keyword
60 Example: income < 1000 and population >= 10000
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62 type=string[,string,...]
63 Input feature type
64 Options: point, line, area
65 Default: point,line,area
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67 output=name [required]
68 Name for output vector map
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70 zshift=float
71 Shifting value for z coordinates
72 Default: 0
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74 height=float
75 Fixed height for 3D vector features
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77 height_column=name
78 Name of attribute column with feature height
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80 elevation=name
81 Elevation raster map for height extraction
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83 method=string
84 Sampling interpolation method
85 Options: nearest, bilinear, bicubic
86 Default: nearest
87 nearest: Nearest-neighbor interpolation
88 bilinear: Bilinear interpolation
89 bicubic: Bicubic interpolation
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91 scale=float
92 Scale factor sampled raster values
93 Default: 1.0
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95 null_value=float
96 Height for sampled raster NULL values
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99 v.extrude creates faces, kernels or 3D lines based on input 2D vector
100 features. Points are converted to 3D vertical lines, lines to faces and
101 areas to volumes (composition of closed set of faces and kernel).
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103 If elevation parameter is used then 3D vector features follow the ele‐
104 vation model by using individual elevation values for the vertices.
105 Height for vertices is interpolated from elevation raster map using
106 given interpolation method.
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109 v.extrude extrudes vector features which means that points are con‐
110 verted to vertical lines. Lines and area boundaries are extruded to a
111 set of faces, each segment defines one face. Area centroids are written
112 as kernels. Area as a composition of boundaries and centroid is stored
113 as a closed set of faces and kernel which define a volume.
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115 For conversion of 2D points or lines to 3D can be used v.to.3d or
116 v.drape. In opposite to v.extrude, these modules do not extrude vector
117 features, they defines z-coordinate for the features from given parame‐
118 ters or by sampling elevation raster map values. It means that no fea‐
119 ture type conversion is applied, points remain still points in the out‐
120 put vector map. Same applies for the lines.
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122 v.extrude modifies only features geometry. Feature categories remain
123 untouched and attribute data is copied from input vector map to the
124 output.
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126 By default, all features (including features without category) from
127 input vector map are processed (layer=-1). Feature selection can be
128 applied by layer, cats or where parameter.
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131 3D houses with fixed height
132 v.extrude input=houses output=houses3D height=5 type=area
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134 3D houses with individual height
135 v.extrude input=houses output=houses3D elevation=dem height_column=height type=area
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137 Convert 2D points to 3D vertical lines with fixed height
138 v.extrude input=geodetic_pts output=points3D height=200 type=point
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141 v.transform, v.extrude, v.drape, v.to.3d
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143 wxGUI 3D viewer
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146 Jachym Cepicky,
147 Updated for GRASS 7 by Martin Landa, FBK-irst, Italy and Czech Techni‐
148 cal University in Prague, Czech Republic
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150 Last changed: $Date: 2014-11-28 17:22:17 +0100 (Fri, 28 Nov 2014) $
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153 Available at: v.extrude source code (history)
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155 Main index | Vector index | Topics index | Keywords index | Graphical
156 index | Full index
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158 © 2003-2019 GRASS Development Team, GRASS GIS 7.6.0 Reference Manual
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162GRASS 7.6.0 v.extrude(1)