[pdal] Modify the resolution

[Silvia Franceschi]

So, I tried to set or not to set the z values but the problem
still persists.
In the info message of the las I can read:
offset x y z:               -676686.38352999999 -5144012.9444300001 0
min x y z:                  -80.5 -83.700000000000003 543.98000000000002
max x y z:                  82.799999999999997 84.850000000000009
591.76999999999998

So definitely the writer changed the offset to the right values but didn't
change the single coordinates... is this correct?
Any idea on what should I do to change all the coordinates?

Thanks again for your help!

Silvia





On Sat, May 11, 2019 at 3:53 PM Silvia Franceschi <
silvia.franceschi at gmail.com> wrote:

> Ok, I was just trying to do this...
> just an additional question: do I have to specify also offset_z and
> scale_z even if  I don't want to change z values?
> So I will put
> offset_z 0
> scale_z 1
>
> Thanks!
>
> Silvia
>
>
> On Sat, May 11, 2019 at 3:47 PM James Klassen <klassen.js at gmail.com>
> wrote:
>
>> You need to set scale_x, scale_y, and scale_z
>>
>> On Sat, May 11, 2019, 08:27 Silvia Franceschi <
>> silvia.franceschi at gmail.com> wrote:
>>
>>> Hi Howard,
>>> thanks for the useful information, I tried to follow your tutorial to
>>> assign a CRS and some real world coordinates to my point cloud using these
>>> parameters:
>>>  "type":"writers.las",
>>>             "a_srs": "EPSG:25832",
>>>     "offset_x": "676686.38353",
>>>     "offset_y": "5144012.94443",
>>>             "filename":"output.las"
>>>
>>> The program seems to work but if I then run an info, it seems that
>>> nothing has changed.
>>> Am I missing something?
>>>
>>> Any suggestion is welcome! :-D
>>>
>>> Silvia
>>>
>>>
>>> On Thu, May 9, 2019 at 2:41 PM Howard Butler <howard at hobu.co> wrote:
>>>
>>>>
>>>>
>>>> On May 9, 2019, at 7:25 AM, thejus kambi <thejus.kambi at gmail.com>
>>>> wrote:
>>>>
>>>> Hello,
>>>>
>>>> Is there a way to modify the resolution of coordinates stored in the
>>>> LAS/LAZ files. I find currently the file stores upto 2 decimal places. Is
>>>> there a way to increase or decrease it?
>>>>
>>>>
>>>> Thejus,
>>>>
>>>> You control these with the writers.las.scale_{x|y|z} options of
>>>> writers.las https://pdal.io/stages/writers.las.html Additionally, if
>>>> you are working exclusively with LAS data, you might also issue the
>>>> --writers.las.forward=all option to carry forward all metadata, including
>>>> scale/offset from a single file transformation.
>>>>
>>>> pdal translate in.las out.las --writers.las.scale_x=0.001
>>>> --writers.las.scale_y=0.001 --writers.las.scale_z=0.001
>>>> --writers.las.offset_x=auto --writers.las.offset_y=auto
>>>> --writers.las.offset_z=auto
>>>>
>>>>
>>>> pdal translate in.las out.las --writers.las.forward=all
>>>>
>>>>
>>>> There are a couple of reasons why we do not default these options to
>>>> always being set:
>>>>
>>>> * What are we to do if the translation includes multiple files at once?
>>>> * Ambiguities that result from changing the LAS version
>>>> * What are we to do in situations where multiple LAS files are being
>>>> written?
>>>>
>>>> It is a surprise, but users have to be explicit about their LAS
>>>> metadata settings with PDAL. Once they are, they should be able to achieve
>>>> most everything they need.
>>>>
>>>> Additionally, I wrote a tutorial of these issues on the website at
>>>> https://pdal.io/tutorial/las.html
>>>>
>>>> Hope this helps,
>>>>
>>>> Howard
>>>>
>>>>
>>>> _______________________________________________
>>>> pdal mailing list
>>>> pdal at lists.osgeo.org
>>>> https://lists.osgeo.org/mailman/listinfo/pdal
>>>
>>>
>>>
>>> --
>>> ing. Silvia Franceschi
>>> Via Roma, 64
>>> 38030 Castello di Fiemme (TN)
>>>
>>> tel: 0039 -3384501332
>>> _______________________________________________
>>> pdal mailing list
>>> pdal at lists.osgeo.org
>>> https://lists.osgeo.org/mailman/listinfo/pdal
>>
>>
>
> --
> ing. Silvia Franceschi
> Via Roma, 64
> 38030 Castello di Fiemme (TN)
>
> tel: 0039 -3384501332
>


-- 
ing. Silvia Franceschi
Via Roma, 64
38030 Castello di Fiemme (TN)

tel: 0039 -3384501332
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