[Liblas-devel] How to use a cached reader (c++)

[Helimap Postmaster]

follow-up:

I see you use std::set as a container, which makes perfect sense on the
kind of data. Unfortunatelly std::set doesn't play well with openmp. Did I
miss another stl container pdal can use?

The library is very clever, and I like the style and design. It's a pity we
might not be able to use it after all.

Cheers,

Pol

On Tue, Mar 15, 2016 at 11:34 AM, Helimap Postmaster <postmaster at helimap.ch>
wrote:

> Hello Howard,
>
> I have a couple questions for you, regarding the pdal library. It reminds
> me of ITK.
>
> For now I won't use the pipeline-style, given that it would take a while
> to refactor the ulterior processing. I will most definitely consider it,
> thought.
>
> At the moment I am looking for a read into a std::vector with either the
> full las cloud or a buffered read of chunk_size size. Reading point by
> point is very inefficient, more so on network drives. Looks like cached
> liblas does that, but doesn't make the vector accessible. It is convenient
> for me to have chunks or the full cloud given that afterwards I do the
> processing for each point in a openmp for. Of course chunks is better,
> given that occasionally the clouds won't fit in memory.
>
> Getting to pdal, there isn't much documentation on the pdal c++ API, is
> there? (e.g. http://www.pdal.io/api/cpp/reader.html ) What methods does
> the reader class provide? Are they thread-safe? You state pdal is not
> parallelized, but can I use the reader in parallel? Does it buffer, and can
> I have access to the buffer?
>
> Cheers,
>
> Pol
>
>
>
> On Tue, Mar 15, 2016 at 9:24 AM, Helimap Postmaster <postmaster at helimap.ch
> > wrote:
>
>> Good morning Howard,
>>
>> This is precious information. I was unaware on liblas being under
>> revision, I'm glad you told me. I'll follow up the pointers you gave, they
>> look promising.
>>
>> Thank you again,
>>
>> Pol
>>
>> On Mon, Mar 14, 2016 at 8:29 PM, Howard Butler <howard at hobu.co> wrote:
>>
>>>
>>> > On Mar 14, 2016, at 9:54 AM, Helimap Postmaster <postmaster at helimap.ch>
>>> wrote:
>>> >
>>> > Hello!
>>> >
>>> > I am currently developing an application which would benefit from
>>> using a buffer when reading a las file.
>>> >
>>> > The C++ API has a CreateCached method in the ReaderFactory, but I
>>> can't seem to discover which is the intended way to use it, there's no
>>> reference anywhere on the documentation, and actually no other method calls
>>> it.
>>> >
>>> > Is it as simple as
>>> >
>>> > liblas::ReaderFactory readerFactory;
>>> > boost::uint32_t cache_size = 1000;
>>> > liblas::Reader reader(lasFStream, cache_size);
>>>
>>> Pol,
>>>
>>> I would suggest if you are starting fresh with including LAS reading
>>> into your software that you start with either PDAL http://pdal.io or
>>> LASlib https://github.com/LAStools/LAStools/tree/master/LASlib
>>>
>>> For LAS files, PDAL is going to allow you to read in a one-at-a-time
>>> streamed fashion or as a giant single buffer. It of course also supports
>>> LASzip and many other point cloud format types.
>>>
>>> Thanks,
>>>
>>> Howard
>>>
>>> PS libLAS is now in "maintenance mode" and should only be used by
>>> projects that have historically used it in the past. If you are doing new
>>> things, you should use PDAL or look to other things like LASlib
>>>
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/liblas-devel/attachments/20160315/c3ea5aa7/attachment-0001.html>