Re: [spdlib-develop] seg fault to wkt file errors

[Narsimha Garlapati]

Hi Dan,
I have executed all the commands as mentioned they work fine for both the 
las1.2 and 1.4 data.
las2las also successfully created new las files for both the versions.
A separate .lax file is also created and I’m unable to read it though…below are 
the outputs.
Hope this info helps for further troubleshooting.

Thanks,
Nash

(spdlib) [nxg650@vdi-n3 las]$ lasinfo -i 687000-6092000.las
lasinfo (160606) report for 687000-6092000.las
reporting all LAS header entries:
  file signature: 'LASF'
  file source ID: 0
  global_encoding:1
  project ID GUID data 1-4:   ----
  version major.minor:1.2
  system identifier:  'LAStools (c) by Martin Isenburg'
  generating software:'lasclip (131105) commercial'
  file creation day/year: 22/2014
  header size:227
  offset to point data:   229
  number var. length records: 0
  point data format:  1
  point data record length:   28
  number of point records:12347548
  number of points by return: 11952454 373899 21147 48 0
  scale factor x y z: 0.01 0.01 0.01
  offset x y z:   -0 -0 -0
  min x y z:  687000.00 6092000.00 562.53
  max x y z:  687999.99 6092999.99 942.59
the header is followed by 2 user-defined bytes
reporting minimum and maximum for all LAS point record entries ...
  X6870   6879
  Y   60920  60929
  Z   56253  94259
  intensity   0235
  return_number   1  4
  number_of_returns   1  4
  edge_of_flight_line 0  1
  scan_direction_flag 0  1
  classification  1  7
  scan_angle_rank   -15 12
  user_data  87 87
  point_source_ID   112134
  gps_time 70360612.990889 70367015.415621
number of first returns:11952454
number of intermediate returns: 21196
number of last returns: 11952424
number of single returns:   11578526
overview over number of returns of given pulse: 11578526 705530 63300 192 0 0 0
histogram of classification of points:
   18300  unclassified (1)
10614832  ground (2)
  521324  low vegetation (3)
  211803  medium vegetation (4)
  980967  high vegetation (5)
 322  noise (7)



(spdlib) [nxg650@vdi-n3 las]$ lasindex -i 687000-6092000.las
before complete 10 -20
after minimum_points 10
largest interval gap increased to 1385
after maximum_intervals 7520

For LAS1.4 data:

(spdlib) [nxg650@vdi-n3 Orthometric]$ lasinfo -i 
ACT2015-C3-ORT_6826096_55_0002_0002.LAS
lasinfo (160606) report for ACT2015-C3-ORT_6826096_55_0002_0002.LAS
reporting all LAS header entries:
  file signature: 'LASF'
  file source ID: 0
  global_encoding:16
  project ID GUID data 1-4:   ----
  version major.minor:1.4
  system identifier:  ''
  generating software:'TerraScan'
  file creation day/year: 53/2016
  header size:375
  offset to point data:   1083
  number var. length records: 1
  point data format:  6
  point data record length:   30
  number of point records:58907333
  number of points by return: 56144061 2069495 587611 97501 8288
  scale factor x y z: 0.01 0.01 0.01
  offset x y z:   -0 -0 -0
  min x y z:  682000.00 6096000.00 472.10
  max x y z:  683999.99 6097999.99 706.30
  start of waveform data packet record: 0
  start of first extended variable length record: 0
  number of extended_variable length records: 0
  extended number of point records: 58907333
  extended number of points by return: 56144061 2069495 587611 97501 8288 370 7 
0 0 0 0 0 0 0 0
variable length header record 1 of 1:
  reserved 0
  user ID  'LASF_Projection'
  record ID2112
  length after header  654
  description  'OGC WKT'
WKT OGC COORDINATE SYSTEM:
PROJCS["GDA94 / MGA zone 
55",GEOGCS["GDA94",DATUM["Geocentric_Datum_of_Australia_1994",SPHEROID["GRS 
1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],TOWGS84[0,0,0,0,0,0,0],AUTHORITY["EPSG","6283"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.01745329251994328,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4283"]],UNIT["metre",1,AUTHORITY["EPSG","9001"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",147],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",50],PARAMETER["false_northing",1000],AUTHORITY["EPSG","28355"],AXIS["Easting",EAST],AXIS["Northing",NORTH]]
reporting minimum and maximum for all LAS point record entries ...
  X6820   6839
  Y   60960  60979
  Z   45289  68704
  intensity   1  23471
  return_number   1  7
  number_of_returns   1  7
  edge

Re: [spdlib-develop] seg fault to wkt file errors

[Daniel Clewley]

Hi Kelsey,

So is the error still with finding the .lax file even after one has been 
generated using lasindex?

The .lax file isn’t used in SPDLib, I’m not sure why LASlib is giving an error 
for that file. Most the files I’ve tested with don’t have a corresponding .lax 
file and they work fine.

Obvious question but have you tested with a different LAS file?

You can test with this one:

http://browse.ceda.ac.uk/browse/neodc/arsf/2014/RG13_06/RG13_06-2014_303_Maliau_Basin/LiDAR/flightlines/discrete_laser/las1.2/LDR-RG13_06-2014-303-35.LAS
 


And the following command:

spdtranslate --if LAS --of UPD -i LDR-RG13_06-2014-303-35.LAS -o 
LDR-RG13_06-2014-303-35.spd -x FIRST_RETURN

I know this file works on my system.

Thanks,

Dan


> On 22 Aug 2016, at 08:01, Kelsey A. Druken  wrote:
> 
> Hi Daniel, 
> 
> Thanks so much for the help there, much appreciated. That explained a lot, 
> thank you. Unfortunately, the v3.3 is still crashing with a seg fault (but 
> those lastool commands seem to execute fine). 
> 
> However, thanks to the info you shared in the last email, I was able to work 
> backwards and get the v3.2 working on our system. In the interest of time, I 
> might leave the intricacies of why v3.3 is still falling over until Adam here 
> returns from overseas travels, as he is more familiar with running these 
> workflows. 
> 
> 
> Nash, I'll followup separately in a moment to work out a time to go over how 
> to get v3.2 working on the VDI for you. That should at least give you 
> something working now on our systems :)
> 
> 
> Thanks so much again Daniel for the help. 
> 
> 
> Cheers,
> Kelsey
> 
> 
> 
> 
> 
> ---
> Kelsey A. Druken
> Earth Systems Data Service Specialist
> National Computational Infrastructure (NCI)
> Leonard Huxley Building, Mills Road
> The Australian National University
> Canberra ACT 0200 Australia
> 
> 
> E: kelsey.dru...@anu.edu.au 
> T: +61 2 6125 2479
> W: nci.org.au 
> 
> 
> On Mon, Aug 22, 2016 at 4:43 PM, Adam Steer  > wrote:
> Great sleuthing Kelsey :) now we are growing another lidar person!
> 
> I had not even thought to check about .lax files. I am also pretty sure you 
> can also use lastools in batch mode to generate lax files for all Nash's data 
> at once.
> 
> Dan - is there an 'ignore lasindex' switch in spdtranslate?
> 
> Cheers
> Adam
> From: Daniel Clewley  >
> Sent: Monday, 22 August 2016 3:39:43 PM
> To: Kelsey Druken
> Cc: spdlib-develop; Narsimha Garlapati
> Subject: Re: [spdlib-develop] seg fault to wkt file errors
>  
> Hi Kelsey,
> 
> Thanks for the info. A ‘.lax’ file is a separate file containing a spatial 
> index for a LAS file. This sounds like LASlib (which the latest version of 
> SPDLib uses to read a LAS file) is looking for the file and not finding it. 
> 
> Nash, was there a .lax file associated with the original LAS file which has 
> been separated at some point?
> 
> If you run the LAStools version of lasinfo (this will be installed with the 
> latest version of SPDLib or can be downloaded separately) what output does 
> this give:
> 
> lasinfo -i 687000-6092000.las
> 
> You could also try exporting to a new LAS file:
> 
> las2las -i 687000-6092000.las -o 687000-6092000_test.las
> 
> It these work OK try to generate a .lax file using:
> 
> lasindex -i 687000-6092000.las
> 
> If they don’t work then LASlib can’t read the LAS file so SPD won’t be able 
> to.
> 
> This might explain why it worked with the previous version (which used libLAS 
> and is unaware of .lax files) but not the newest version of SPDLib (which 
> uses LASlib).
> 
> Thanks,
> 
> Dan
> 
>> On 22 Aug 2016, at 05:38, Kelsey A. Druken > > wrote:
>> 
>> Hi Nash, 
>> 
>> Of course- please feel free. (I will note, I did try a few different 
>> versions and combinations of libraries in my troubleshooting but I think it 
>> is still good for you to have a try.)
>> 
>> 
>> 
>> Dan- apologies to bother you but could I just ask one quick question 
>> regarding the software? If I do a strace when trying to execute this sample 
>> command:
>> 
>> $ spdtranslate --if LAS --of SPD -b 10 -x LAST_RETURN -i 
>> ./687000-6092000.las -o lidartest.spd --temppath ./tempspd
>> 
>> 
>> the segmentation fault continually happens after this statement where it 
>> can't find a file of the same name with the extension '.lax':
>> 
>> open("./687000-6092000.lax", O_RDONLY)  = -1 ENOENT (No such file or 
>> directory)
>> 
>> --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x6} ---
>> 
>> +++ killed by SIGSEGV +++
>> 
>> 
>> I am not familiar with lidar processing tools myself, so my apologies in 
>> advance if this is a silly question. My colleague (Adam, more familiar with 
>> lidar- ga