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

[Hamish]

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