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<em>v.extrude</em> creates faces, kernels or 3D lines based on input
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2D vector features. Points are converted to 3D vertical lines, lines
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to faces and areas to volumes (composition of closed set of faces and
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If <b>elevation</b> parameter is used then 3D vector features follow
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the elevation model by using individual elevation values for the
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vertices. Height for vertices is interpolated from elevation raster
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map using given interpolation <b>method</b>.
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<em>v.extrude</em> extrudes vector features which means that points
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are converted to vertical lines. Lines and area boundaries are
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extruded to a set of faces, each segment defines one face. Area
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centroids are written as kernels. Area as a composition of boundaries
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and centroid is stored as a closed set of faces and kernel which
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For conversion of 2D points or lines to 3D can be
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used <em><a href="v.to.3d.html">v.to.3d</a></em>
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or <em><a href="v.drape.html">v.drape</a></em>. In opposite
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to <em>v.extrude</em>, these modules do not extrude vector features,
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they defines z-coordinate for the features from given parameters or by
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sampling elevation raster map values. It means that no feature type
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conversion is applied, points remain still points in the output vector
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map. Same applies for the lines.
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<em>v.extrude</em> modifies only features geometry. Feature categories
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remain untouched and attribute data is copied from input vector map to
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By default, all features (including features without category) from
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input vector map are processed (<b>layer=-1</b>). Feature selection
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can be applied by <b>layer</b>, <b>cats</b> or <b>where</b>
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<h3>3D houses with fixed height</h3>
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<div class="code"><pre>
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v.extrude input=houses output=houses3D height=5 type=area
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<h3>3D houses with individual height</h3>
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<div class="code"><pre>
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v.extrude input=houses output=houses3D elevation=dem height_column=height type=area
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<h3>Convert 2D points to 3D vertical lines with fixed height</h3>
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<div class="code"><pre>
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v.extrude input=geodetic_pts output=points3D height=200 type=point
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<a href="v.transform.html">v.transform</a>,
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<a href="v.extrude.html">v.extrude</a>,
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<a href="v.drape.html">v.drape</a>,
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<a href="v.to.3d.html">v.to.3d</a>
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<a href="wxGUI.nviz.html">wxGUI 3D viewer</a>
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Updated for GRASS 7 by Martin Landa, FBK-irst,
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Italy and Czech Technical University in Prague, Czech Republic
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<i>Last changed: $Date: 2014-11-28 17:25:40 +0100 (Fri, 28 Nov 2014) $</i>