[GRASS-user] lidar data - nnbathy x bspline

[Carlos "Guâno" Grohmann]

Ciao Roberto.

Nice work with v.surf.bspline! I ran some tests, this time no
artifacts were produced in the sub-regions limits. Alsdo it is very
fast!

I'd just like to poin some issues:

- You could add, in the output messages, a indication of how many
sub-regions will be used, so the user knows approximately how much of
the interpolation has been done, how much still left.

- I tried to use the --overwrite option, but it didn't work.

- I did a test on an area 3.2x0.9 km, with 1m resolution, and it
worked fine. When I changed the resolution to 0.25m, I got an error
msg:

>GRASS_INFO_ERROR(12405,3): Interpolation: The region resolution is
too high: 46080000.000000 cells. Consider to change it.

It worked with a resolution of 0.33m, but the resultant surface were
with a "pixelated" look, I don't know if is a problem with bspline or
GRASS dealing with non-round values for UTM regions.


That's all for now. If I find anything more, I'll let you know


Carlos




On 1/15/07, Roberto Antolin <roberto at geomatica.como.polimi.it> wrote:
> Hi Carlos and all,
>
> Carlos "Guâno" Grohmann ha scritto:
>
> > I was wondering how to avoid these artifacts with bspline? or with we
> > could have a vector version of nnbathy?
> >
> > Carlos
> >
> >
> > http://www.igc.usp.br/pessoais/guano/temp/lidar_bspline.jpg
> >
> > http://www.igc.usp.br/pessoais/guano/temp/lidar_nnbathy.jpg
> >
> I was working on it and I've just update cvs. Now interpolation with
> v.surf.bspline should works quite nice.
>
> Regards,
> Roberto.
>
> --
> Roberto Antolín Sánchez
> Politecnico di Milano – Polo Regionale di Como
> (Laboratorio di Geomatica V2.8)
> Via Valleggio, 11 – 22100 Como, Italy
> tel: +39 031 332 7533 || fax: +39 031 332 7519
> email: roberto.antolin at polimi.it
>
>


-- 
+-----------------------------------------------------------+
              Carlos Henrique Grohmann - Guano
  Geologist M.Sc  - Doctorate Student at IGc-USP - Brazil
Linux User #89721  - carlos dot grohmann at gmail dot com
+-----------------------------------------------------------+
_________________
"Good morning, doctors. I have taken the liberty of removing Windows
95 from my hard drive."
--The winning entry in a "What were HAL's first words" contest judged
by 2001: A SPACE ODYSSEY creator Arthur C. Clarke