[GRASSLIST:1675] Voxel data

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).

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?

Thanks in advance,

Artemis.

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

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