[GRASS-user] Error in v.vol.rst

[Manuel Seeger]

Hello Markus, hello Hamish, and List!

I imported a transformed shapefile.
g.region -p gives:
projection: 1 (UTM)
zone:       30
datum:      wgs84
ellipsoid:  wgs84
north:      4681874.175
south:      4681826.55
west:       624764.175
east:       624839.625
nsres:      0.075
ewres:      0.075
rows:       635
cols:       1006
cells:      638810

as it is a gully headcut, I have steep slopes (vertical!) and overhangs 
and some shadowing...

Thanks again!

Manuel




Hamish schrieb:
> Manuel Seeger wrote:
>   
>> I trying to generate a 3d DEM of a gully headcut. The point
>> data was gained by terrestrial laser scanner.
>>     
>
> what is the form of the raw data? x,y,z point cloud?
>
> is there only one x,y for each z, or are there overhangs?
>
> I ask because if there is only one z for each x,y then perhaps a 2.5D surface is more appropriate and the processing is much simpler:
>   http://grass.osgeo.org/wiki/Help_with_3D#Raster_2.5D_Surfaces
>
> that may obscure fine details of steep slopes though, lumping them all into one horizontal cell. Maybe the cell resolution would have to be very small.
> If that isn't good enough an idea, if you don't mind it, is to switch the z coordinate with x or y when you import and then look at the thing side on.
>
>
>   
>> As I am doing my first attempts, I do not change any
>> parameters from that given by default.
>>
>> This is the result:
>> v.vol.rst input=BAR1_SCAN_UTM at Georef41 wcolumn=dbl_3 tension=40. 
>>   smooth=0.1 segmax=50 npmin=200 dmin=0.050026 wmult=1.0 zmult=1.0 
>>   elev=Olite_3d --overwrite
>>
>> 1511728 records selected from table
>>
>> some points outside of region -- will ignore...
>>
>> strip exists with insufficient data
>>
>> Processing all selected output files will require 1435616
>> bytes of disk space for temp files
>>
>>
>> There are points outside specified 2D/3D region--ignored
>> 57754 points (total points: 1511728)
>>
>> Points are more dense than specified
>> 'DMIN'--ignored 1131669 points 
>> (remain 380059)
>> Percent complete:
>>
>> Error in COGRR!
>>
>> Interp_call failed!
>>
>> Can someone give me an idea if this is my fault?
>>     
>
> No idea about that.
>
>
> Hamish
>
>
>
>       
>
>
>   


-- 

_______________________________________________________________________
Dr. Manuel Seeger
Wiss. Assistent 			Scientific Assistant
Physische Geographie 			Dpt. of Physical Geography
FB VI - Geographie/Geowissenschaften 	Geography/Geosciences
Universität Trier			University of Trier
D - 54286 Trier
Tel.:	+49-651-201 4557
Fax:	+49-651-201 3976
Web:	http://www-neu.uni-trier.de/index.php?id=9607