<div dir="ltr"><div><div>Hello,<br><br></div>I have written a PDAL pipeline to perform the following steps:<br><br>1.) Ferry the existing Classification to the UserData field for storage (this is more efficient than creating a new field)<br></div><div>2.) Use the ferry filter to create a new DTM field<br></div><div>3.) Use the colorize filter to extract the elevation value from a single-band TIF (a DTM made from the original ground points)<br></div><div>4.) Run SMRF to reclassify the ground points<br></div><div><br>I cannot get the ferry filter to work at all. It won't transfer values between existing columns or create new columns, despite using the same syntax described on PDAL.io.
I have tried various ways to get around this issue. Changing the order
of filters.ferry in the pipeline didn't make a difference. I saw that
the online examples worked on uncompressed LAS files, so I converted the
input files from LAZ to LAS but there was no change. The pipeline completes without errors, but info --stats and info --schema show that the ferried fields were not created or updated.<br>
<br>The colorize filter works fine, as long as I use an existing field. For example,
"dimensions":"Red:1:1000.0" works by mapping the elevation values to the Red field and multiplying by 1000 to preserve millimeter precision in an integer field. However,
"dimensions":"DTM:1:1000.0"
does not, because the ferry filter doesn't create the DTM field. The SMRF filter also works well, but without the ability to ferry values I lose the original classifications.<br></div><div><br></div><div>I am using PDAL 1.6.0 on Windows within OSGeo4W. It was installed this month. My pipeline is copied below.<br><br></div><div>Any help would be greatly appreciated.<br><br></div><div>Thanks,<br></div><div>Eric<br><span style="font-family:monospace,monospace"><br><br>{<br> "pipeline":<br> [<br> "C:/data/forest_park/filtered/forest_park_orig.laz",<br> {<br> "type":"filters.ferry",<br> "dimensions":"Classification=>UserData, =>DTM"<br> },<br> {<br> "type":"filters.colorization",<br> "dimensions":"DTM:1:1000.0",<br> "raster":"C:/data/forest_park/dtm/w001001.adf"<br> },<br> {<br> "type":"filters.smrf",<br> "cell":1.00,<br> "cut":0,<br> "scalar":1.25,<br> "slope":0.00,<br> "threshold":0.50,<br> "window":10<br> },<br> {<br> "type":"writers.las",<br> "tag":"writerslas",<br> "compression":"true",<br> "scale_x":"0.01",<br> "scale_y":"0.01",<br> "scale_z":"0.01",<br> "offset_x":"auto",<br> "offset_y":"auto",<br> "offset_z":"auto",<br> "filename":"C:/data/forest_park/forest_park_orig_dtm.laz"<br> }<br> ]<br>}</span><br></div></div>