Global Mapper v25.0

Exporting Lidar LAS after EDIT_VECTOR

Qiao
Qiao Global Mapper UserTrusted User
edited January 2013 in Vector Data
Hi Mike,

I am trying to modify the CLASS attribute values for a loaded Lidar LAS layer and then export the layer to a new Lidar LAS file. The resulting Lidar LAS file however has the attributes unchanged. I tried both editing the attributes in Global Mapper or using scripting command EDIT_VECTOR. Both the same. In Global Mapper it showed me that the attributes have been changed (for the loaded original layer). But each time exporting to a new file, it used the original unedited values. Do you have any insights? It seems to me that the editing is done in RAM while the exporting is done by re-reading the file from disk (not from the edited version in RAM).

Thanks,

Qiao

Comments

  • global_mapper
    global_mapper Administrator
    edited March 2012
    Qiao,

    You hit the nail on the head, it was indeed going back to the source file and ignoring the customized attributes. I have fixed this so now editing the CLASS or INTENSITY attributes will keep those edits on export rather than using what is in the original file. I have placed a new build at http://www.globalmapper.com/global_mapper13.zip with the latest changes for you to try. Simply download that file and extract the contents into your existing v13.xx installation folder to give it a try. If you are using the 64-bit v13 version there is a new build at http://www.globalmapper.com/global_mapper13_64bit.zip .

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • Qiao
    Qiao Global Mapper User Trusted User
    edited March 2012
    Thanks Mike. I tried your new build. It worked fine.
  • laughlin
    laughlin Global Mapper User Trusted User
    edited January 2013
    Hi Mike,

    I have a similar challenge here, using GM12_64 -- losing my Class value edits on export to new LAS file. Short of upgrading which sounds like the obvious fix, is there a temporary workaround? I need to reset Class values to 0 so i can run data thru MCC-LiDAR and work with terrain models of results in GM. There is just too much built-in classification of ground that is really veg response in the data set i have. Only other solution i can find seems to be in LasTools.

    appreciate any leads,
    Laughlin

    Qiao,

    You hit the nail on the head, it was indeed going back to the source file and ignoring the customized attributes. I have fixed this so now editing the CLASS or INTENSITY attributes will keep those edits on export rather than using what is in the original file. I have placed a new build at http://www.globalmapper.com/global_mapper13.zip with the latest changes for you to try. Simply download that file and extract the contents into your existing v13.xx installation folder to give it a try. If you are using the 64-bit v13 version there is a new build at http://www.globalmapper.com/global_mapper13_64bit.zip .

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com
  • global_mapper
    global_mapper Administrator
    edited January 2013
    Laughlin,

    You can export to a Simple ASCII Text (XYZ) file first, then load that back in and export that to a LAS file. The issue with the class files being lost is only when exporting from a LAS to a new LAS.

    Of course upgrading is the best course. We are about to release v14.1 that has a massively upgraded Lidar engine, supports upwards of a billion points! It is also much faster and has more display options.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.bluemarblegeo.com/