July 27, 2017

Recent versions of SAGA GIS no longer support importing files in the .las format. However, a .las file can be converted using PDAL’s writers.text module into a text file format, which in turn can be imported in SAGA. For this example, we will begin with a .las file projected in a state plane CRS that is the output of my post Reprojecting LIDAR .las files to Latitude/Longitude to State Plane Example.

  1. Open a new text file named las2xyz.json in the same directory as your .las file and paste the following into it:
    {
      "pipeline": [
        {
          "type": "readers.las",
          "filename": "20131013_usgs_olympic_wa_10TDT310990.las"
        },
        {
          "type": "writers.text",
          "order": "X,Y,Z",
          "keep_unspecified": "false",
          "quote_header": "false",
          "delimiter": ",",
          "filename": "20131013_usgs_olympic_wa_10TDT310990.txt"
        }
      ]
    }
  2. Now run the pipeline. This may take a while. Once it completes, you should now see the converted .txt file in the working directory.
    pdal pipeline las2xyz.json
    ls -hs -1 
    total 1.1G
    227M 20131013_usgs_olympic_wa_10TDT310990.las
    148M 20131013_usgs_olympic_wa_10TDT310990.laz
    745M 20131013_usgs_olympic_wa_10TDT310990.txt
    4.0K las2xyz.json
    4.0K lat_lng_WA_S_FIPS_ft_reprojection.pipeline.json
    
  3. Let’s perform a quick sanity check on this new file:
    less 20131013_usgs_olympic_wa_10TDT310990.txt
    X,Y,Z
    803169.892,932562.842,2093.730
    803170.060,932566.158,2093.070
    803178.839,932573.593,2054.360
    803170.851,932564.554,2093.700
    803225.508,932562.372,2043.070
    803232.723,932560.928,2040.090
    803232.361,932562.222,2041.790
    803232.443,932564.117,2041.470
    803234.863,932568.358,2030.210
    803235.004,932568.206,2034.440
    803236.294,932567.895,2028.310
    
    
  4. Open SAGA GIS. From the Geoprocessing menu, select File -> Tables -> Import -> Import Text Table with Numbers only
    Import Text Table from SAGA GIS Geooprocessing menu
  5. Select the .txt point cloud file that was created by PDAL, with the appropriate options as shown in the screenshot. Click Okay. Since the example text file used is nearly 1.0 GB in size, importing may take some time.
    SAGA GIS - Import text table with numbers only
  6. Once the text file has been imported as a table into SAGA, select Geoprocessing -> Shapes -> Point Clouds -> Conversion -> Point Cloud from Table.
    SAGA GIS - Point Cloud from Table Menu
  7. Select the table that was created in the previous step, and then set the values for X/Y/Z to these columns from the table.
    SAGA GIS - Point Cloud From Table
  8. Afterwards, you will get the point cloud generated in your data sources.
    SAGA GIS - Point Cloud in Data sources
  9. From the Geoprocessing menu, select Visualization -> 3D Viewer -> Point Cloud Viewer. Select Z as the colored attribute.
    SAGA GIS - Geoprocessing 3d visualization
    SAGA GIS - Point Cloud Viewer Dialog
  10. Click Okay. The point cloud will be displayed in SAGA’s Point Cloud Viewer tool:
    SAGA - Point Cloud in Point Cloud Viewer