[pgpointcloud] Overlapping patches

[Nilesh Vyavahare]

Hi Howard,

Sorry for the delayed reply. I was away for a week.

Your guess is absolutely right. The scaling and selector filters are causing the overlapping patches. I ran the pipeline again for a pc schema that holds all the attributes without the selector and scaling filter in the pipeline and the resultant patches are non-overlapping!

I am not sure what the best around this problem is. The one I could think of for now is, I might have to load the las file into some temporary table with all the dimensions which points to default pc schema  and them transfer each patch into my destination table with selected dimensions.

Thanks again.
Nilesh

-----Original Message-----
From: Howard Butler [mailto:howard at hobu.co]
Sent: Friday, January 31, 2014 6:53 PM
To: Nilesh Vyavahare
Cc: pgpointcloud at lists.osgeo.org
Subject: Re: [pgpointcloud] Overlapping patches

> You should not be getting *any* overlap for single-run chipper calls. Can you describe more completely how you are generating your inserts and coming  up with a 90% overlap value?
>
> I am reading the las file all at once and specifying it to be split into patches of 400 points before inserting it into pgpointcloud. I have attached an example of pipeline I am running. When I said 90% overlap, it wasn’t any computational, it was mere visual interpretation. I have attached a screenshot which shows various overlapping patch extent generated after the insert of patches from a file. It also shows overlapping points in there as well. I am not quite sure what am I doing wrong here.

So patch 1 and patch 2 were generated by reading the same 110008.las file in the same pipeline? If so, I wonder if your filters.scaling and other options are jiggling your points. Can attempt a pipeline that is just

drivers.las.reader -> filters.cache -> filters.chipper -> drivers.pgpointcloud.writer

and see if that produces overlapping patches for a single LAS file?



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