Lidar point cloud creating unwanted anomalies in surface

[cblakeman]

Hello all,

My company has recently acquired a drone with LiDAR capabilities. I am working on the processes to use LiDAR and I have run into issues. 

After processing the lidar within a third party software and converting into a Recap project, I am left with ground points only. Once brought into a Civil3D drawing and creating a surface, there seems to be mounts over empty spaces where buildings were.

I have ensured that there are no points that could cause anomalies within these areas, and I do not use a filter when creating the surface within Civil3D.

The point cloud is in the correct spot, and all of the other elevations seem to be correct. I have included an example below. Has anyone else had this issue, or does anyone know what could be going on?

I am working in ft and INSUNITS are set to 2.

I can include the recap file if necessary. 

[ChicagoLooper]

Would it be possible to upload the las or laz file? Include points for bare earth and points above ground. What is the native coordinate system of the las/laz file?

[Pointdump]

Hi Chase,
Welcome to the Autodesk Forums.
Yes, posting your ReCap files would be good. Please zip them together and post.
Which third party software are you using to filter ground points?
Dave

[AllenJessup]

Without examining the files. I'd guess that there is still a small portion of building face left. The software tries to extend the surface along that face and meet the extension from the opposite side of the building. I'd suggest adding a Data Clip Boundary or at least a Hide Boundary for the buildings.

Another option may be to limit the length of triangles in the Surface to cut out those within the buildings.

[cblakeman]

The coordinate system is IN83-EF horiz. and NAVD88 (usft) vert.. I cannot attach the .las because of autodesk file limits, and the .zip is still too large. 

[cblakeman]

Dave, attached is the unifed recap file. We are testing out many softwares, this point cloud was classified with LiDAR360 from Greenvalley International.

[Pointdump]

Chase,
For files larger than the Forum's 71MB limit, use WeTransfer, DropBox, or MEGA.
Dave