[GRASSLIST:1677] Re: Voxel data

[Artemis]

Thanks for the answer, but I still
have some questions:

The data about the vein is
stored with two values for the coord
this way:

            hole
surface  -----|-----
              |
              v1
ore vein xxxxxxxxxxx
              v2
              |
              |

where v1 and v2 represent the height of 
top and bottom of the ore, and there's
no z as such.

currently, I store them this way:
(in the site list)
east|north| %v1 %v2
...

east and north are coordinates
of the bore hole.

Then I did s.vol.idw on it with
option field=1 and 2 with output
to two different files. The vein
looks realistic, but it stretches 
from top to the very bottom of the
3D-window. The question is, how to
make it round (or at least bounded
by v1 and v2 for each segment) 
in 3D-space?

Perhaps, something is to be done
with s.to.rast3 or r3.mapcalc?

Thanks again,

Artemis.

On Wed, Mar 28, 2001 at 01:22:53PM +0100, Markus Neteler wrote:
> Hi Artemis,
> 
> On Wed, Mar 28, 2001 at 05:13:26PM +0700, Artemis wrote:
> > Hi all,
> > 
> > My question is on working with grid3d
> > datasets. I have some point data of
> > the following format:
> > 
> > east north top bottom 
> > 
> > It was taken from bore hole data
> > and is representing a metal vein
> > (top and bottom are the top and bottom
> > of the vein in the hole).
> 
> to store such data you would need this structure:
> 
>  east1 north1 z1 val1 val2 ...
>  east2 north2 z2 val2 val2 ...
>  ...
> 
> This you can import with
>  s.in.ascii d=3 in=input.asc sites=out
> 
> > When I interpolate either top or bottom
> > values with s.vol.idw, I get the vein
> > displayed but like a thin band stretching
> > from the very top to the very bottom of the
> > 3d-box.
> > 
> > Perhaps I do something wrong or I need
> > to get some additional data?
> I fear that s.vol.idw is somewhat broken. In fact the entire G3D modules/
> library have some problems, see the bug list here:
> 
> http://freegis.org/cgi-bin/viewcvs.cgi/~checkout~/grass/src.contrib/GMSL/g3d/src3d/BUGS
> 
> However, the s.vol.rst module seems to work o.k (precompiled binary here:
> http://www.geog.uni-hannover.de/grass/grass5/binary/linux/)
> 
> We need volunteers who analyse the inconsistencies in G3D lib and modules.
> 
> Regards
> 
>  Markus Neteler
> 
>