Cannot Apply LAS Dataset to LASHeight (Classify)

[Justin Eddings]

I am working with 154 LAS files merged into a single LAS dataset and I am having trouble running the lasheight (classify) tool to separate bare earth from vegetation and buildings. I started working with a batch but that is taking forever to apply the same parameters 154 times. Second thought was model tool but again, the time to link 154 individual LAS input files and produce an output file name is very long. Can I merge the 154 files into one LAS? Thanks.

[Martin Isenburg]

Hello,

in a private message Justin also included the control output below. From that we can parse that his merged input file to lasheight contains 764,142,862 points of which 197,475,187 are ground points. For lasheight to work this would require now to build a TIN surface with around 200 million vertices and 400 million triangles which will take way more Gigabytes than a 32 bit application can allocate and which also will be slow because the TIN would be a rather large search structure to find the triangle above which each point is located. The secret to efficient LAStools processing is to operate spatially coherent *BUFFERED* tiles of around 5 to 15 million points.

https://rapidlasso.com/2015/08/07/use-buffers-when-processing-lidar-in-tiles/

To do this with the Arghhhh, you will need to use the production toolbox "LAStools Pro" in ArcGIS that can operate on folders of files. Maybe best to avid the Arghhhh altogether and use the native GUIs or batch scripts and follow the many examples in this user forum and on our http://rapidlasso.com/blog

Regards,

Martin @rapidlasso

Executing: lasheight-classify "D:\LAS Merge\LAS_Merge11.las" # "ground (2)" # # "low point (7)" -10 "low vegetation (3)" 0.5 5 "medium vegetation (4)" 5 10 "high vegetation (5)" 10 100 "building (6)" 100 las "C:\GIS Databases\PSEG Viewshed - Bethpage\LAS Dataset\LAS Reclassified\LAS_Merge11_Reclass" "C:\GIS Databases\PSEG Viewshed - Bethpage\LAS Dataset\LAS Reclassified" # # true

Start Time: Wed Oct 18 16:43:44 2017

Running script lasheight-classify...

Starting lasheight ...

Found C:\Users\jeddings\Downloads\LAStools\LAStools\bin ...

Found C:\Users\jeddings\Downloads\LAStools\LAStools\bin\lasheight.exe ...

LAStools command line:

"C:\Users\jeddings\Downloads\LAStools\LAStools\bin\lasheight.exe" -v -i "D:\LAS Merge\LAS_Merge11.las" -class 2 -classify_below -10 7 -classify_between 0.5 5 3 -classify_between 5 10 4 -classify_between 10 100 5 -classify_above 100 6 -olas -o "C:\GIS Databases\PSEG Viewshed - Bethpage\LAS Dataset\LAS Reclassified\LAS_Merge11_Reclass" -odir "C:\GIS Databases\PSEG Viewshed - Bethpage\LAS Dataset\LAS Reclassified"

Please note that LAStools is not "free" (see http://lastools.org/LICENSE.txt)

contact 'martin....@rapidlasso.com' to clarify licensing terms if needed.

first pass. reading 764142862 points to count ground points ...

took 1417.92 sec. counted 197475187 ground points.

ERROR: cannot alloc point_buffer for 197475187 points.

       contact martin....@rapidlasso.com for help on what to do.

 

Error. lasheight failed.

Completed script lasheight-classify...

On Wed, Oct 18, 2017 at 8:03 PM, Justin Eddings <justin....@gmail.com> wrote:

I am working with 154 LAS files merged into a single LAS dataset and I am having trouble running the lasheight (classify) tool to separate bare earth from vegetation and buildings. I started working with a batch but that is taking forever to apply the same parameters 154 times. Second thought was model tool but again, the time to link 154 individual LAS input files and produce an output file name is very long. Can I merge the 154 files into one LAS? Thanks.

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