[GRASSLIST:7953] Re: [GRASS5] 3D Rasters in current CVS

[Michael Barton]

Markus,

I gave this a try. All went well except the nviz part. I can see the frame
for the volume, but not the shape. Just a blank screen. I tried to change
several of the values, but it was not help.

I'm using a July 16 MacOSX version.

Michael
__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution and Social Change
Arizona State University
Tempe, AZ 85287-2402

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton



> From: Markus Neteler <neteler at itc.it>
> Date: Wed, 17 Aug 2005 21:08:18 +0200
> To: Benjamin Ducke <benducke at compuserve.de>
> Cc: <grasslist at baylor.edu>, <grass5 at grass.itc.it>
> Subject: [GRASSLIST:7953] Re: [GRASS5] 3D Rasters in current CVS
> 
> Hi Benjamin,
> 
> as Helena suggests, there will be an issue with your WIND file
> which now contains the 3D info.
> 
> I made a quick funny test in spearfish60, works well:
> 
> #Set 3D region:
> g.region res3=100 b=800 t=1600 -p3
> 
> #generate a volume:
> r3.mapcalc "vol1=sin(x())+cos(y())+sin(z())"
> 
> #fetch range (average around zero):
> r3.info -r vol1
> 
> # visualize
> nviz elevation.dem vol=vol1
> 
> #-> go Panel -> Volumes -> Add -> New Constant -> 0 [return] -> Accept
> # Now wait some seconds to get the colume rendered
> 
> Looks nice...
> 
>  Markus
> 
> On Wed, Aug 17, 2005 at 06:33:50PM +0200, Benjamin Ducke wrote:
>> r3.mapcalc seems broken in current CVS (?). Even the most simple
>> operation like
>> 
>> result = input * 10
>> 
>> gives this error:
>> 
>> FATAl ERROR: G3d_getDoubleRegion: error in G3d_getTilePtr
>> 
>> NVIZ is giving me some trouble, too. I don't understand what
>> information NVIZ uses to position a 3D raster map in space.
>> I have tried loading in a plain surface with height range 4 to 9
>> meters and a 3D raster with Z boundaries set to the same values.
>> However, the latter is being positioned well below the surface
>> (the data range of the 3D raster is about 1.0 to 3.0).
>> The X/Y positioning seems correct.
>> I can change the Z position manually but am still unable to display anything
>> using the "slices" method. ISO-surface extraction seems to work.
>> Any ideas, why this is so?
>> 
>> I would really like to use voxels/3D rasters in GRASS and volunteer to write
>> a tutorial on it, but I feel currently very vague about some aspects of
>> implementation.
>> First, I would like to understand the working of r3.in.ascii a bit better:
>> am I right in thinking that every raster map in the input file defines the
>> lower faces of one level of voxels and that voxels are stacked from bottom to
>> top?
>> Can 3D rasters also be integers or only fp?
>> 
>> 
>> Thanks,
>> 
>> Benjamin. 
>> 
> 
> -- 
> Markus Neteler     <neteler itc it>       http://mpa.itc.it
> ITC-irst -  Centro per la Ricerca Scientifica e Tecnologica
> MPBA - Predictive Models for Biol. & Environ. Data Analysis
> Via Sommarive, 18        -       38050 Povo (Trento), Italy