[GRASS5] Voxels/3D rasters in GRASS 6.1

[Markus Neteler]

On Fri, Jul 01, 2005 at 11:50:57AM +0200, benducke at compuserve.de wrote:
> This is another mail in my desperate quest for handling 3D data
> in GRASS. I am trying voxels this time and got stuck just as
> quickly as with 3D vectors.
> Maybe someone could answer some of the questions I have.
> I am using GRASS 6.1 CVS (about 2 weeks old).
> 
> 1. Do all commands that relate to voxels have r3. prefix now? Which
> other commands relate to voxels?

Yes: r3.*
- plus v.vol.*
- plus g.* for file/region management (was g3.* in earlier days)


> 2. r3.in.ascii mentions s.to.rast3 is there an equivalent command for
>    this in 6.1?

No. I think that s.to.rast3 still needs to be ported as v.to.rast3.


> 3. When trying to visualise a voxel in nviz, I get:
> 
>   Illegal filename. character <> not allowed.G__open(r): mapset (benni)
> doesn't    match xmapset (ô¯@DHäÿ¿|v at 5&òr@ÿÿÿÿ@äÿ)
> 
>   on the console. Am I using a broken version of nviz?

Doesn't look good. I used the Slovakia data set a few days
ago without problems.
 
> 4. Why does r3.info not give information about the data range?

AFAIK: No, that's a TODO.

> 5. How do I get actual volume information, do I have to count the
>    non NULL cells in the voxel map, then add them up? Is there
>    any command that can give me 3D raster voxel statistics?

There is not too much yet, I believe.

> 6. Is there any CURRENT information about voxels and GRASS on the
>    web?

Should be. Please help to improve the documentation...

> I would be very happy indeed about any information on this subject!
> 
> Cheers,
> 
> Benjamin

Markus