[Liblas-devel] Las2Oci problems

[Howard Butler]

Tom,

You could register for an account at http://trac.liblas.org and attach it to a ticket there.

Martin,

SPfinalizer's code is not open source, correct?

Howard

On Apr 18, 2011, at 4:48 AM, T.J.F. Commandeur wrote:

> Thank you for the fast replies.
> 
> Martin:
> 
> My code is mostly taken from SPfinalizer but filtered only to what I needed.
> Sharing the code is not a problem for me, but further development is not
> possible because of my studies. The balanced point counts is not used but
> only splitting into a quadtree and merging the cells into a MAXIMUM points
> per cell due to the block size setting of Oracle. This maximum is based on
> your minimum in SPfinalizer.
> 
> Howard:
> 
> No problem for finding the bug, I read through the source code of Las2Oci
> but couldn't find wherein the problem lies. As noted above it is not
> possible for me to create such a patch or collaborate on the libPC project
> due to my studies. Besides that these could be some notes to keep in mind
> while developing libPC? Looking at the projects I am happy to see that
> people are developing open-source las/point cloud software!
> 
> Michael:
> 
> Of course I am willing to provide the source code. Mostly is copied/based on
> SPfinalizer. To whom and where could I send the source to?
> 
> Kind regards,
> Tom Commandeur
> 
> -----Oorspronkelijk bericht-----
> Van: Michael P. Gerlek [mailto:mpg at flaxen.com] 
> Verzonden: vrijdag 15 april 2011 18:26
> Aan: 'Howard Butler'; 'T.J.F. Commandeur'
> CC: liblas-devel at lists.osgeo.org
> Onderwerp: RE: [Liblas-devel] Las2Oci problems
> 
> Following up on Howard's comments on libPC: I'd really like to have a
> routine in there that creates a quadtree of based on spatial regions.  If
> you are willing to put the code under a BSD license, I'd be willing to
> integrate into the library.
> 
> -mpg
> 
> 
>> -----Original Message-----
>> From: liblas-devel-bounces at lists.osgeo.org [mailto:liblas-devel-
>> bounces at lists.osgeo.org] On Behalf Of Howard Butler
>> Sent: Friday, April 15, 2011 6:39 AM
>> To: T.J.F. Commandeur
>> Cc: liblas-devel at lists.osgeo.org
>> Subject: Re: [Liblas-devel] Las2Oci problems
>> 
>> 
>> On Apr 15, 2011, at 8:01 AM, T.J.F. Commandeur wrote:
>> 
>>> Hi all,
>>> 
>>> For scientific research I created another kind of Lasblock based on
> spatial
>> finalization by M. Isenburg (spfinalizer).
>>> This program is able to process larger point clouds and has a low memory
>> footprint based on a quadtree structure.
>>> When the program is done it creates either separate las files for every
>> block or a las and kdx file.
>>> Now these are created I want to load them to an Oracle spatial SDO_PC
>> with Las2Oci.
>>> I am using libLAS from OS4geo on windows, during the usage of Las2Oci I
>> found some strange things.
>> 
>> Excellent!  I'm glad you found the code useful in some way.
>> 
>>> -          When writing las to a database using a kdx file Las2Oci tends
> to
>> duplicate the last block written to the database (kdx created by
> Lasblock).
>> 
>> * Thanks for finding this.  It must be a bug.
>> 
>>> -          Las2Oci loads the complete kdx file into memory which seems
> quite
>> insufficient for memory usage. Can't the kdx be read line by line (block
> by
>> block) instead of completely at once?
>> 
>> * Yes, it could be made to do this. That it doesn't is because it was
> going to be
>> approached later when it became a problem.
>> 
>>> -          When executing Las2Oci without a kdx file but with multiple
> las files it
>> creates a new point cloud for every file. There is no option to add new
> blocks
>> to an existing point cloud instead when using multiple las files.
>> 
>> We would need a patch to fix this.
>> 
>>> 
>>> Is there a solution to these problems? Do I need to change my workflow
>> for using Las2Oci to indeed add las files to an existing point cloud in
> the
>> database?
>> 
>> I have been working on the OCI stuff under a different framework that
>> Michael Gerlek and I have been developing called libPC.  It's intent is
> more of
>> a "GDAL for Point Clouds" with things arranged in a processing pipeline.
> This
>> has a number of advantages over the libLAS OCI efforts, which are quite
> tied
>> to LAS. The lasblock code is available as a "filter" within this pipeline,
> and it
>> would be conceivable for you to make a filter using your modified
> spfinalizer
>> code as well if this is something you are interested collaborating on.
>> 
>> http://hg.libpc.org/main is where the code lives.  It is quite rough in
> many
>> ways, and there are definitely no prebuilt windows binaries that can
>> consume those kdx files yet, but the basics of OCI reading and writing are
>> there.
>> 
>> Howard
>> 
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> 
>