[GRASSLIST:7406] Voxels/3D rasters in GRASS 6.1

[benducke at compuserve.de]

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?

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

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?

4. Why does r3.info not give information about the data range?

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?

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

I would be very happy indeed about any information on this subject!

Cheers,

Benjamin