[pdal] Merging buffered tiles

[Andrew Bell]

I opened this ticket to address this issue:

https://github.com/PDAL/PDAL/issues/2009

On Thu, May 3, 2018 at 4:30 PM, Eric Robeck <erobeck at gmail.com> wrote:

> Andrew,
>
> Sure, no problem. I sent you and Howard copies of the files in a separate
> email. They are as follows:
>
> 1.  "clean_tile_18.las": the original file I created using PDAL to tile
> and convert from LAZ 1.4 to LAS 1.2)
> 2.    "mcc_tile_18.las": the tile created by MCC-LIDAR after ground
> classification
> 3.    "lasground_tile_18.laz": the tile created by LASTools lasground.exe
> from the LAS file, but recompressed by lasground
>
> I also think I identified the problem. I thought the input 'mcc' tiles
> were in Missouri East State Plane coordinates, because I had projected some
> MCC inputs before, so I told PDAL to convert them from EPSG 26915 (Missouri
> East State Plane) to EPSG 32615 (UTM 15N):
>
>       "inputs":"merge_tiles",
>       "type":"filters.reprojection",
>       "tag":"reproject_tiles",
>       "in_srs":"EPSG:26915",
>       "out_srs":"EPSG:32615"
>
> Apparently PDAL was smarter than me, because it recognized the inherent
> coordinate system and did NOT reproject the data. When I took out the
> reprojection stage and ran the pipeline again, it finished without errors.
> PDAL protected me from my own mistake, so maybe that was its way of
> detecting the discrepancy.
>
> I hope that helps.
>
> Regards,
> Eric
>
> On Thu, May 3, 2018 at 2:54 PM Eric Robeck <erobeck at gmail.com> wrote:
>
>> Sure, no problem. I've attached copies of my smallest tile here. They are
>> as follows:
>>
>>    - "clean_tile_18.las": the original file I created using PDAL to tile
>>    and convert from LAZ 1.4 to LAS 1.2)
>>    - "mcc_tile_18.las": the tile created by MCC-LIDAR after ground
>>    classification
>>    - "lasground_tile_18.laz": the tile created by LASTools lasground.exe
>>    from the LAS file, but recompressed by lasground
>>
>> I also think I identified the problem. I thought the input 'mcc' tiles
>> were in Missouri East State Plane coordinates, because I had projected some
>> MCC inputs before, so I told PDAL to convert them from EPSG 26915 (Missouri
>> East State Plane) to EPSG 32615 (UTM 15N):
>>
>>       "inputs":"merge_tiles",
>>       "type":"filters.reprojection",
>>       "tag":"reproject_tiles",
>>       "in_srs":"EPSG:26915",
>>       "out_srs":"EPSG:32615"
>>
>> Apparently PDAL was smarter than me, because it recognized the inherent
>> coordinate system and did NOT reproject the data. When I took out the
>> reprojection stage and ran the pipeline again, it finished without errors.
>> PDAL protected me from my own mistake, so maybe that was its way of
>> detecting the discrepancy.
>>
>> I hope that helps.
>>
>> Regards,
>> Eric
>>
>>
>> On Thu, May 3, 2018 at 1:33 PM Andrew Bell <andrew.bell.ia at gmail.com>
>> wrote:
>>
>>> Any chance you could share a couple of your input files?
>>>
>>> On Thu, May 3, 2018 at 2:26 PM, Andrew Bell <andrew.bell.ia at gmail.com>
>>> wrote:
>>>
>>>> I'm confused by the error you get.  I'll run a test to see if I can
>>>> figure out what might be going on.
>>>>
>>>> On Thu, May 3, 2018 at 12:02 PM, Howard Butler <howard at hobu.co> wrote:
>>>>
>>>>>
>>>>> > On May 3, 2018, at 10:49 AM, Eric Robeck <erobeck at gmail.com> wrote:
>>>>> >
>>>>> > Howard,
>>>>> >
>>>>> > Yes, the parentheses crept in early while I tried to keep track of
>>>>> the various parameter combinations used for my bare earth simulations, but
>>>>> they caused headaches later on...
>>>>> >
>>>>> > As an update, I ran a slightly modified version of the same pipeline
>>>>> (sample tile geometries, different source files) and got no errors. This
>>>>> time the input files were in LAZ format and they were not reprojected.
>>>>> Another factor could be that the first set were generated by the old(ish)
>>>>> MCC-LIDAR application, and the latter by Isenburg's lasground.exe.
>>>>>
>>>>> That fact pattern would seem to confirm my hunch. This srs stuff is
>>>>> definitely a topic we could improve.
>>>>>
>>>>> Howard
>>>>> _______________________________________________
>>>>> pdal mailing list
>>>>> pdal at lists.osgeo.org
>>>>> https://lists.osgeo.org/mailman/listinfo/pdal
>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Andrew Bell
>>>> andrew.bell.ia at gmail.com
>>>>
>>>
>>>
>>>
>>> --
>>> Andrew Bell
>>> andrew.bell.ia at gmail.com
>>>
>>


-- 
Andrew Bell
andrew.bell.ia at gmail.com
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