topic Re: Surface Constraints in LASD in 3D Questions

Surface Constraints in LASD

LauraHanson1 — Sun, 17 Mar 2013 15:38:35 GMT

I am trying to clip down and las dataset using the surface constraints, within LASD properties. I have a 2D polygon shapefile for this at the moment which doesn't seem to do anything. Does this need to be 3D and and what kind of surface feature should it be? Or is this a bug I have come across as there seems to be little information regarding surface constraints in the help.

Thanks

Laura

Re: Surface Constraints in LASD

CarrieDavis — Mon, 18 Mar 2013 15:18:22 GMT

Hi Laura,

A 2D polygon can be used as a surface constraint to clip a Las dataset. I think what you are experiencing is that the surface constraints are only taken into consideration when triangulation is occurring. This is a known limit. The surface constraint "Hard Clip" will clip the Las Dataset only when it is displayed as a TIN surface. I hope this helps.

Best wishes.

Re: Surface Constraints in LASD

DavidGuerra1 — Fri, 17 May 2013 14:34:25 GMT

Hi,

We are having a very similar problem.
I have a LASD with many .las files.

I want to filter my LASD by a shape file so that all the .las files that fall within this shape file are preserved, and all of the .las files that fall outside of this shape are discarded.

I am attempting to do this by using the shape file as a surface constraint (in the create LAS Dataset properties) and selecting hard or soft clip, but this process is not working. All my .las files are kept, and no filtering occurs.

Any idea how to fix this?