Hello,
I am dealing with large LAS file that is output of AgiSoft Photoscan. I need to generate break lines and isohypses.
In this question I have seen the potential solution but I think this can't solve both of my needs. I hope I can get some hint.
Thank you all in advance,
With respect,
Dejan
What do you mean by break lines?
What do you mean by break lines?
There are many software that do that but I am trying to do it with FME. I have done the part of isohypses but I don't know how to generate break lines.
Any hint would be useful.
Thank You in advance!
Wild idea: generate a tin and look for triangles that are very steep, then dissolve them and generate centerlines.
In theory it should work as long as your LAS is detailed enough. But... that'll increase processing time.
Another suggestion for extracting the breaklines:
- Use the TinGenerator to generate triangles and TINedges
- Send the triangles to a PlanarityFilter with expose surface normal set to yes
- Send the edges to a CoordinateExtractor to store the 3D coordinates
- Send both streams to a TopologyBuilder, with propagate All Attributes set to yes. This will produce edges that have the surface normal for each adjoining triangle.
The TopologyBuilder will force the edges to 2D, but you can use the stored coordinates to restore the original geometry. By comparing the normals of the adjoining triangles, you can determine if the edge should be a break line or not.
Were you able to find a solution to this? I found this question looking for answers to the same problem. I'm just starting and am trying the suggestions offered in the replies.
Thanks,
Justin