[GRASS-dev] fixes before 6.2.1 [was: ps.map: scale wrong and
michael.barton at asu.edu
Mon Nov 20 11:52:10 EST 2006
What I have found so far is that what is displayed is very strongly
dependent on polygon resolution--especially for isosurfaces. If you set it
wrong, you can get nothing, rendering that will last into the next day, or
different looking surfaces. I'm not sure it's incorrect, but it is very
sensitive. The critical resolutions will also depend on the size of the
region and number of voxels in the volume. I've had to experiment with each
volume I do.
Michael Barton, Professor of Anthropology
School of Human Evolution & Social Change
Center for Social Dynamics and Complexity
Arizona State University
> From: Benjamin Ducke <benjamin.ducke at ufg.uni-kiel.de>
> Date: Mon, 20 Nov 2006 13:39:08 +0100
> Cc: <grass-dev at grass.itc.it>
> Subject: Re: [GRASS-dev] fixes before 6.2.1 [was: ps.map: scale wrong and no
> 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.
> 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)
>>>> It would be nice to fix this one too:
>>> 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.
>> grass-dev mailing list
>> grass-dev at grass.itc.it
> Benjamin Ducke, M.A.
> (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
> Tel.: ++49 (0)431 880-3378 / -3379
> Fax : ++49 (0)431 880-7300
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