[GRASS-dev] convert 3D polygons or Tins to a DEM?

[Benjamin Ducke]

I noticed this one too a few days back when I was looking for a
3D hull algorithm. Looks like a promising collection of algorithm
for GRASS.

However, for a quick fix of v.delaunay, as suggested by Helena:
Might it not be enough to replace the 2D distance measure in
v.delaunay with a 3D distance, so it will do the tesselation in
3D space correctly?
I could try and find some time to look into that if you think
it feasible.

Benjamin



Markus Neteler wrote:
> On Jan 28, 2008 9:29 AM, Maris Nartiss <maris.gis at gmail.com> wrote:
>> Fixing large dataset and 3D support problems would be a nice
>> improvement of GRASS vector support :)
> 
> Possibly we need to substitute the algorithm? I found for example
> http://www.qhull.org/
> "Qhull computes the convex hull, Delaunay triangulation, Voronoi
> diagram, halfspace intersection about a point, furthest-site Delaunay
> triangulation, and furthest-site Voronoi diagram. The software runs in
> 2-d, 3-d, 4-d, and higher dimensions. Qhull implements the Quickhull
> algorithm for computing the convex hull. It handles roundoff errors
> from floating point arithmetic. Qhull also computes volumes, surface
> areas, and approximations to the convex hull."
> 
> (seems to be GPL compliant)
> 
> Markus
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> 

-- 
Benjamin Ducke, M.A.
Archäoinformatik
(Archaeoinformation Science)
Institut für Ur- und Frühgeschichte
(Inst. of Prehistoric and Historic Archaeology)
Christian-Albrechts-Universität zu Kiel
Johanna-Mestorf-Straße 2-6
D 24098 Kiel
Germany

Tel.: ++49 (0)431 880-3378 / -3379
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