[Qgis-developer] Lidar data into QGIS

[Larry Shaffer]

Hi,

I contacted Howard Butler, one of the developers of PDAL, about possibly
providing some input on questions we have in this thread, and believe he is
now subscribed to the list.

Howard, any ideas on a strategy for using PDAL in QGIS, e.g. via proposed
GDAL support, as a separate data provider, and/or utilizing its command
line utilities via a Processing plugin provider?

Regards,

Larry


On Wed, Jan 29, 2014 at 7:48 AM, A Huarte <ahuarte47 at yahoo.es> wrote:

> But then we must preprocess the data before load it in QGIS
>
>   ------------------------------
>  *De:* Randal Hale <rjhale at northrivergeographic.com>
> *Para:* qgis-developer at lists.osgeo.org
> *Enviado:* Miércoles 29 de enero de 2014 14:49
> *Asunto:* Re: [Qgis-developer] Lidar data into QGIS
>
> Would LASTools add anything to the conversation? I do believe they
> re-order the file (but I've not used it).
>
>
> -----------------
> Randal Hale, GISP
> North River Geographic Systems, Inc
> http://www.northrivergeographic.com
> 423.653.3611 rjhale at northrivergeographic.com
> <mailto:rjhale at northrivergeographic.com>
> twitter:rjhale
> http://about.me/rjhale
>
> On 01/29/2014 08:25 AM, Jean-Roc Morreale wrote:
> > Most lidar files are not spatially ordered so with a sequential read
> > you will end up reading the whole file, it's like accessing a untiled
> > unpyramided bigtiff : painful.
> >
> > Le 2014-01-29 13:52, A Huarte a écrit :
> >> I think but using a quadtree approach there is a problem, and it is
> >> none other than the construction of the quadtree itself for so big
> >> data.
> >>
> >> IMHO I would use a specific provider (with a specific featureiterator)
> >> reading sequentially the LAS file and discarding points before fetch
> >> it to renderer using the RectangleFilter of current FeatureRequest. It
> >> avoid create many-many QgsFeature's that after are discarded in
> >> renderer side.
> >>
> >> I use this technique in a personal viewer, and after first read of
> >> file (the file is cached in SO), the following drawings are quite
> >> fast.
> >>
> >> Alvaro
> >>
> >>> -------------------------
> >>> DE: Jean-Roc Morreale <jr.morreale at enoreth.net>
> >>> PARA: qgis-developer at lists.osgeo.org
> >>> ENVIADO: Miércoles 29 de enero de 2014 13:32
> >>> ASUNTO: Re: [Qgis-developer] Lidar data into QGIS
> >>>
> >>> Can it performs fast enough to display hundred millions points or
> >>> billions at once ? Does it leverage a quadtree approach ?
> >>>
> >>> Le 2014-01-29 12:55, A Huarte a écrit :
> >>>> yes, it can be implemented on renderer level (Martin Dobias
> >>> propose
> >>>> it) or on featureiterator level similar to current simplification
> >>>> classes for line and polygons
> >>>>
> >>>> I think it is pending for a test of performance
> >>>> Best Regards
> >>>> Alvaro
> >>>
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> >>
> >>
> >>
> >> Links:
> >> ------
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