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  1. I'm using Ubuntu Linux and have installed QGIS 3.22 which has native support for LAS files. I think that LAStools is for MS Windows only?
  2. I can load the LAS data and see a pretty image.
  3. Next, I want to use the ground classified spot heights to make a Digital Elevation Model, e.g. this procedure which requires a shapefile.
  4. Is there some way to extract ground classified XYZ from the LAS and save that as a shapefile? Or is there some other way to create a DEM? This is looking too difficult for me.
Vince
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stweb
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  • Did you try the Las2dem tool in QGIS ? Depending on your study area you will either need to use the Las2demPro or to split your dataset ! – wanderzen May 30 '23 at 12:15
  • Welcome to GIS SE. As a new user, please take the [Tour], which emphasizes the importance of asking One question per Question. We're a problem-solving site, so you need to provide sufficient details that that problem could be reproduced and a fix offered. – Vince May 30 '23 at 12:38
  • Does this answer your question? Creating DEM from LAS file without using LAStools? – GBG May 30 '23 at 14:58
  • It appears that both LAStools and Fusion are Windows only. I think that I shall copy my data to a Windows machine, install LAStools and do my processing in Windows. – stweb May 31 '23 at 02:14
  • Oh, LAStools is not free. – stweb May 31 '23 at 02:20
  • The list of which LAStools are free and which aren't is Here. – Pointdump May 31 '23 at 07:23
  • You definitely can create a dem with las data in QGIS with the free version of LasTools. Las2dem is meant for this but as I said you will have to split your .las dataset if it is too big otherwise you will have to upgrade to the prenium version – wanderzen May 31 '23 at 13:53
  • LAStools are not windows only. You can run them fine on linux with wine https://www.winehq.org/ – zwnk Jul 05 '23 at 00:34
  • Thanks, but no thanks. I'm using PDAL because it doesn't cost an arm and a leg, works directly on Linux, modern and fast (CLI interface). Similarly, QGIS rather than ArcGIS, OpenStreetMap rather than Google Maps and so on. There are some good alternatives to commercial offerings out there folks. Be part of a community rather than just another customer. – stweb Jul 06 '23 at 04:18

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  1. I installed PDAL (Point Data Abstraction Library). PDAL is free, open source and includes lots of modern tools for point cloud data. PDAL is run from a terminal, which makes it fast (large datasets are difficult in QGIS).
  2. I followed the instructions here for creating a DEM and, with reference to the PDAL website, I quickly learned how to write the JSON 'pipelines' (scripts). PDAL also has filters for Delaunay triangulation and interpolation of that output (in more recent versions).

I recommend PDAL for processing point cloud data.

stweb
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