[pdal] Modify the resolution

[Silvia Franceschi]

Yess,
thanks Andrew, I tried and specified the value of scale_z to 1 to preserve
my heights.

Silvia


On Sat, May 11, 2019 at 10:13 PM Andrew Bell <andrew.bell.ia at gmail.com>
wrote:

> If you don't want the defaults, you need need to specify values. See the
> documentation for details about default values.
>
> On Sat, May 11, 2019, 4:01 PM James Klassen <klassen.js at gmail.com> wrote:
>
>> If you don't set Z, I believe it will use the defaults/automatically
>> determined values for Z.
>>
>> Personally, if I like to set all 6 (x/y/z both offset and scale) if I set
>> any of them.  It probably doesn't make any difference, but it seems like
>> less room for surprises later.
>>
>> On Sat, May 11, 2019, 08:53 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
>>>
>> _______________________________________________
>> 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
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