<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Apr 12, 2018, at 11:05 PM, Eric Robeck <<a href="mailto:erobeck@gmail.com" class="">erobeck@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><div class=""><div class="">Hello,<br class=""><br class=""></div>I have written a PDAL pipeline to perform the following steps:<br class=""><br class="">1.) Ferry the existing Classification to the UserData field for storage (this is more efficient than creating a new field)<br class=""></div></div></div></blockquote><div><br class=""></div><div>Did you find this to be the case? Adding another dimension shouldn't really have an extra cost.</div><br class=""><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><div class="">2.) Use the ferry filter to create a new DTM field<br class=""></div></div></div></blockquote><br class=""><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><div class="">3.) Use the colorize filter to extract the elevation value from a single-band TIF (a DTM made from the original ground points)<br class=""></div></div></div></blockquote><div><br class=""></div><div>Pete Gadomski made a post about this contorted scenario that's currently required. See <a href="http://www.gadom.ski/2018/02/28/pdal-hs.html" class="">http://www.gadom.ski/2018/02/28/pdal-hs.html</a> for some details.</div><br class=""><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><div class="">4.) Run SMRF to reclassify the ground points<br class=""></div><div class=""><br class="">I cannot get the ferry filter to work at all. </div></div></div></blockquote><div><br class=""></div><div>The syntax in your pipeline is 1.7's syntax, but you stated you're using 1.6.0. This might be the discrepancy. We want to make this scenario better. filters.colorization is a bad name for what it does (it's really raster overlay). 1.7 fixed the precision issue [1] when doing the task.</div><br class=""><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><div class="">It won't transfer values between existing columns or create new columns, despite using the same syntax described on <a href="http://PDAL.io" class="">PDAL.io</a>.
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 class="">
<br class="">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 class=""></div><div class=""><br class=""></div><div class="">I am using PDAL 1.6.0 on Windows within OSGeo4W. It was installed this month. My pipeline is copied below.<br class=""></div></div></div></blockquote><div><br class=""></div><div>PDAL 1.7.1 is now available via OSGeo4W64. I don't know that this will solve any issues for you, but we will be talking about the same codebase as far as functionality goes. I know that the filters.ferry syntax was amended to be more explicit about where data from dimensions should be going.</div><div><br class=""></div><div>Hope this helps. Pete's write-up is a good one of how to achieve what you're after.</div><div><br class=""></div><div>[1] <a href="https://github.com/PDAL/PDAL/pull/1841" class="">https://github.com/PDAL/PDAL/pull/1841</a></div></div><br class=""></body></html>