[GRASS-dev] patch for v.voronoi/v.delaunay

[Markus Neteler]

Hi Benjamin,

On Fri, Feb 1, 2008 at 2:16 PM, Benjamin Ducke
<benjamin.ducke at ufg.uni-kiel.de> wrote:
> Hi all,
>
>  As per request, I have patched v.delaunay (source in v.voronoi/)
>  very carefully.
>
>  The memory handling now seems to work better. At least I was able
>  to triangulate a map with ca 30000 points. Anything more and my
>  system starts thrashing badly (1 GB, with a lot of other apps running).
>  Feel free to test with bigger inputs.

I tried with nearly 40k points and it worked.

>  The output vector map will now also preserve the 3D coordinates of
>  the original input points. However, the centroids for the triangles
>  are all wrong (placed at z=0.0). I don't see a quick way of fixing
>  this right now.

I have fixed it using Vect_tin_get_z() for delaunay (someone needs to
do it for voronoi).

I have submitted the fixed code to SVN:
http://trac.osgeo.org/grass/changeset/31079

For me it now generates a 3D Delaunay TIN.

>  In fact, I'd prefer not to touch the current code for v.delaunay
>  anymore. It is in urgent need of a complete overhaul as it is
>  inefficient, hard to read and still full of site lib artefacts.
>  Better to re-write from scratch with more time on my (or someone
>  else's) hands.

Forthcoming...:
http://code.google.com/soc/2008/osgeo/appinfo.html?csaid=7599B5B1E8D1F20F

Markus