Blast2dem issue

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Jan 21, 2022, 4:10:01 PMJan 21
to LAStools - efficient tools for LiDAR processing
Support / LAStool Community,

I am performing a test where I am not getting desired results.  I have a 2x2 block of contiguous LAS files I want to convert to DEM rasters, tiled into 500x500 meter tiles. I am using the most recent LAStools .EXEs.  I have a Blast license. Intent is to perform this task on 1000s of LAS tiles.

My cmd line is below:

C:\LAStools\bin\blast2dem -v -i *.las -merged -kill 200 -nodata -9999 -tiling_ns test 500 -keep_class 2 14 20 -step 1.0 -cores 14 -odir .\BND_DEM\BLAST -oimg -epsg 6343

Below are the processing remarks:

G:\DATA_FOR_PROCESSING\DEM_GEN_TEST>C:\LAStools\bin\blast2dem -v -i *.las -merged -kill 200 -nodata -9999 -tiling_ns crater 500 -keep_class 2 14 20 -step 1.0 -cores 14 -odir .\BND_DEM\BLAST -oimg -epsg 6343
using projection EPSG code 6343
WARNING: input files merged on-the-fly. ignoring '-cores 14' ...
llx/lly unspecified. set to lower left bounding box 691239/3.49371e+006.
terrain finalization (using 2d quadtree) to level 8 with empty 0.
have bounding box. first pass not needed.
second pass: populating finalization counter grid ...
using projection EPSG code 6343
ERROR: unknown file format. file name '(null)' must end in
       *.bil *.asc *.flt *.dtm *.xyz *.img *.png *.jpg *.tif *.csv *.laz
second pass: done. created 51415 leaf grid cells and stored 51415 sprinkle points
spfinalizer: needed 6.89 seconds
created parent grid cells (new total is 69285 cells)
third pass: using finalization grid to spatially finalize 35184187 points...
output precision is float ...
lower left x unspecified. setting it to 691239.
lower left y unspecified. setting it to 3.49371e+006.
ncols was unspecified. we set it to 3018.
nrows was unspecified. we set it to 3521.
third pass: done. stored at most 40462968 chunked points (plus 51415 sprinkle points)
spfinalizer: needed 59.779 seconds
duplicate_points 642
spdelaunay2d: needed 59.756 seconds
read 35184187 points. produced TIN with 35183545 vertices and 70367049 triangles
tin2dem: needed 63.458 seconds
took 70.616 sec to create '(null)'.


No output is generated.

Interested if anyone has dealt with this issue and knows of a solution.  ERROR referenced above suggests a syntax issue(?)

Thank you,

Support at rapidlasso

Jan 27, 2022, 2:09:24 AMJan 27
to LAStools - efficient tools for LiDAR processing
Hi Bobby,
sorry for let you waiting...
Your verbose output suggest something is wrong with the filename
generation - "file name '(null)'..."
If you use tiling_ns parameter blast2dem extract the file endings out of the given filename.
Extend your command with a filename does the job:

blast2dem -v -i *.las -merged -kill 200 -nodata -9999 -tiling_ns crater 500
-keep_class 2 14 20 -step 1.0 -cores 14 -odir .\BND_DEM\BLAST -oimg
-epsg 6343 -o foo.img

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