GRASS LiDAR tools [it was Re: [Liblas-devel] Hello!]

[Roberto Antolín]

Hi Howard and all,

Howard Butler wrote:

> Roberto,
> Did you have to write LAS reading/writing software as part of your 
> effort, or did you dump the LiDAR data to text before consuming the data 
> with GRASS and beginning your processing?

This is exactly how it works: making an intermediate ascii file before 
importing it into grass. To be honest, I "didn't care" about LAS format 
since all the data I was supply with was in text format.

Besides, old grass versions (more than four years ago) permitted to work 
with "site_lists" [1], that is text files, which made grass a perfect 
software for lidar data management. Unfortunately, it was impossible 
with new version, where only binary grass vector and raster are allowed. 
Still, it is possible to import lots of vector and rasters formats. In 
fact, when we thought to update the old lidar commands, we decided to 
use the builtin r.in.xyz and v.in.ascii modules in order to import lidar 
data as text.

I've took a look into the Mateusz's thread in the grass-devel list and I 
agree that, by the moment and as a fast thing, it would be possible to 
make a wrapper with last2txt and v.in.ascii or r.in.xyz. Later, it would 
be great to make a *.in.las command or something like that. I don't know 
whether it is possible/necessary/useful to embed libLAS to work directly 
with the grass lidar tools (v.lidar.*).

[1] easting|northing|[z|[d4|]...][#category_int] [@attr_text OR %flt]

Regards,
Roberto.

-- 
Roberto Antolín Sánchez
Departamento de Tecnología

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