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NAMEv.hull - Produces a 2D/3D convex hull for a given vector map. KEYWORDSvector, geometry, 3D SYNOPSISv.hull
Flags:Parameters:
DESCRIPTIONv.hull computes the convex hull of a vector map and outputs the convex hull polygon as a vector area map. The convex hull, or convex envelope, for an object or a set of objects is the minimal convex set containing the given objects. This module creates a vector polygon containing all vector points or lines of the input map. In the case of 3D input points, the hull will be a 3D hull as
well, unless the user specifies the -f flag. The 3D hull will be
composed of triangular faces.
NOTESIn order to use the where option the layer option must be set to a positive number (the default is ’-1’ for ’all layers’), otherwise all points from all layers will be used and the cats and where options will be ignored. EXAMPLEExample of v.hull 3D output (using two random 3D point
clouds, North Carolina sample data set):
g.region rural_1m -p r.mapcalc "zero = 0" v.random -z output=random3d_a n=10 zmin=0 zmax=200 v.random -z output=random3d_b n=15 zmin=400 zmax=600 v.hull input=random3d_a output=random3d_a_hull v.hull input=random3d_b output=random3d_b_hull d.mon wx0 d.vect random3d_a_hull d.vect random3d_a color=red d.vect random3d_b_hull d.vect random3d_b color=red # 3D view in wxGUI (g.gui) Fig: Convex hull in 3D from 3D points created with v.hull REFERENCES
SEE ALSOv.delaunay AUTHORSAndrea Aime, Modena, Italy
SOURCE CODEAvailable at: v.hull source code (history) Latest change: Wednesday Nov 27 22:53:26 2024 in commit: b90ce69e88409469369ec1edb86fde8ec822af8b Main index | Vector index | Topics index | Keywords index | Graphical index | Full index © 2003-2025 GRASS Development Team, GRASS GIS 8.4.1 Reference Manual
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