The Point Cloud .LAS file - What is it good for?

Data Processing - Discussion and Q&A
1

At the moment…absolutely nothing for me. I’m using QGIS as my primary means of interacting with the DD data and I was hoping I would be able to convert the point cloud .LAS file into a DEM so that I could then use that to create slope models, hillshaded surface models and relief models etc. Using LAStools in QGIS or Fusion or any other point cloud software like Fugro Viewer gets me absolutely nowhere with these .LAS files from DD. Is there something peculiar to the data in them that I am missing ? Does anyone have a foolproof walkthrough of how to convert a DD .LAS file into a usable DEM ?

2

@markwalters
I am not a QGIS user so I can not speak to that; however I do use the LAS files. I utilize the files in Civil 3d and make surfaces/TIN files from the data. The LAS is preferred due to the additional properties that it has compared to the XYZ files. The issue I ran into initially with the LAS files is that they are in Latitude, Longitude, Elevation format, which was not usable for me. I have converted it to State Plan within Civil 3D or Safe FME and I can then work with it.

Also I have spoken to DD multiple times about being able to change the projection of the LAS files, like we can with the XYZ files, and they have indicated that this is in the works. I obviously hope that it is in the “soon to be released” works, but that’s just me :slight_smile:

1 Like
3

Thanks @dragonflyAS - yes the ability to change the projection would be useful. I can view the point cloud in LAStools lasviewer, but trying to get the las2dem tool to convert the file to a DEM achieves nothing so far. I suspect the file needs re-projecting and possibly classifying, but I am not sure.

@neema it would be really useful if DD could do a LAS to DEM conversion guide for QGIS

4

@markwalters
Ever issue I have run into was because of the default coordinate system of the DD LAS files. Most things do not like lat/long. Does the QGIS let you work with the XYZ point files? I do not like them; however you can have the file reprojected by DD and delivered.

@neema
Feel free to remind Henery, Chris and the rest of the engineering/implementation team that it would be AWESOME to have the LAS reproejction tool available from the dashboard :slight_smile:

Have a Happy Thanksgiving!

1 Like
5

@dragonflyAS I haven’t messed around much with the .xyz files, but will give it another go. I think QGIS can handle them after conversion in LAS tools