[GRASS-dev] fixes before 6.2.1 [was: ps.map: scale wrong and no output]

[Benjamin Ducke]

OK, I have done some experimenting and this is what it looks like for
me:

It indeed seems to be a problem with small region settings.
Basically, anything with a cell resolution < 1.0 in any axis does not
seem to display (i.e. results gets totally displaced as illustrated
in the screenshot I sent earlier).

IN ADDITION, the number of rows, cols and depths must at least be
10! If any of those fall below, the result gets more or less strongly
displaced.

Now, I am not sure if this is a problem with some sort of scaling or
translation, maybe something that also happens with larger cells and
region settings but goes unnoticed in those cases, because the offsets
shrinks to a very small value ???

I am not sure if that also makes sense in relation to Michael's report.

Benjamin



Helena Mitasova wrote:
> Benjamin,
> 
> can you do a small test to confirm that the problem is indeed with
> small numbers by multiplying the coordinates in your area by 100 (so you 
> will
> get res=5) and see whether nviz volumes still don't work?
> The volumes support for nviz was implemented when the 3D region
> was handled separately from 2D region, after everything was merged into
> a single file it may not be reading the region correctly when the 
> numbers are small,
> 
> thanks Helena
> 
> Benjamin Ducke wrote:
> 
>> Just a few observations on nviz volume support, hope it provides some
>> useful informations.
>>
>> For me, the slovakia3d volume has always worked with NVIZ. Also, when I
>> create a new volume in that location, I can vizualize it with NVIZ w/o
>> problems. E.g.:
>>
>>     r3.mapcalc tmp=1.0
>>
>> works fine, also if I change the 3D region settings, e.g
>>
>>     g.region b=2000.0
>>     r3.mapcalc tmp2=2.0
>>
>> still displays OK.
>>
>> HOWEVER, for my vizualization tasks I use very small, local coordinate
>> ranges (archaeological site stratigraphies of just a few cubic meters)
>> with very small 3d cell sizes.
>> E.g., I have a 3D region set to this:
>>
>> projection: 0 (x,y)
>> zone:       0
>> north:      61
>> south:      58
>> west:       14
>> east:       17
>> top:        12.00000000
>> bottom:     9.00000000
>> nsres:      0.05
>> nsres3:     0.05
>> ewres:      0.05
>> ewres3:     0.05
>> tbres:      0.05
>> rows:       60
>> rows3:      60
>> cols:       60
>> cols3:      60
>> depths:     60
>> cells:      3600
>> 3dcells:    216000
>>
>> Now, when I create a simple volume like above, It does not display in
>> nviz, I can neither create iso surfaces nor slices.
>> When I zoom out (increasing the "Height" slider) then NVIZ * sometimes *
>> shows the outlines of the volume and I can see, that it has been totally
>> displaced, below my 3d working region (see attached image)!
>>
>> Apparently, there are some scale effects here and nviz cannot handle
>> volumes at these small region and resolution settings.
>>
>> Another remaining problem (though not a bug) is that NULL values
>> in volumes cannot be set transparent independently of other 3d cell
>> values (not so sure if this is possible for 2d rasters in nviz).
>>
>> Well, good luck fixing these and the other issues with nviz.
>> I think it would be tremendously important to finally have working
>> 3d raster vizualization in GRASS. I for one would be extremely
>> grateful for it.
>>
>> Benjamin
>>
>> Markus Neteler wrote:
>>
>>> Maciej Sieczka wrote on 11/16/2006 07:07 PM:
>>>
>>>> Hamish wrote:
>>>>
>>>>  
>>>>
>>>>> So ps.map is pretty much broken in 6.2.0. Bummer.
>>>>>
>>>>> If we can figure out why NVIZ volumes are broken and fix the following
>>>>> bug, I'd vote for a quick 6.2.1 release.
>>>>>
>>>>> NVIZ volume problem (test with slovakia3d dataset) - sometimes it 
>>>>> works
>>>>> * fails from command line; ok if the volume added within NVIZ (bug 
>>>>> #4725)
>>>>>   http://intevation.de/rt/webrt?serial_num=4725
>>>>>
>>>>>
>>>>> It would be nice to fix this one too:
>>>>>   https://intevation.de/rt/webrt?serial_num=5209
>>>>>    
>>>>
>>>>
>>>> Fixing the gis.m, so that it preserved the aspect ratio for
>>>> single-click zooming in the restricted mode, is also a critical issue.
>>>>  
>>>
>>>
>>> There are some fixes which didn't make it yet into gis.m of 6.2. There
>>> was offlist communication between Michael, Hamish and me on that
>>> but I completely lost track which change should be submitted there.
>>>
>>> Markus
>>>
>>> _______________________________________________
>>> grass-dev mailing list
>>> grass-dev at grass.itc.it
>>> http://grass.itc.it/mailman/listinfo/grass-dev
>>>
>>>
>>
>>
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> 
> 
> 

-- 
Benjamin Ducke, M.A.
Archäoinformatik
(Archaeoinformation Science)
Institut für Ur- und Frühgeschichte
(Inst. of Prehistoric and Historic Archaeology)
Christian-Albrechts-Universität zu Kiel
Johanna-Mestorf-Straße 2-6
D 24098 Kiel
Germany

Tel.: ++49 (0)431 880-3378 / -3379
Fax : ++49 (0)431 880-7300
www.uni-kiel.de/ufg