I have a multibeam bathymetric survey and LiDAR around a caving stream bank, and the reality for most of it is that the bank probably has formed temporary shallow "caves" for much of it, though some probably did collapse between the two different survey dates. When triangulating the points, ORD seems to be picking the shortest trianulation path for the XY direction, and ignoring the Z direction, creating these "spikes" instead of a nice smooth terrain.
Is there a way to adjust how the TM triangulates to adjust most of these, and perhaps identify which points need to be removed to account for subsequent micro-failures in the stream bank?
Otherwise I suppose I'll have to manually clip down the earlier data set POD file before extracting both to create the Terrain Model.
Delauney triangulation algorithm is used to create the terrain, and this does not allow 'overhang' features. There is settings to be able to adjust this, so you will have to manually amend the data.
https://en.wikipedia.org/wiki/Delaunay_triangulation
I am not understanding your second sentence; there are, or are not settings to adjust the method or otherwise account for overhang features in a terrain? I have clipped the pointcloud to remove the overhanging points, and will have to add contingency to my quantities to account for this; is there a better way to resolve this issue in the future?
Sorry - missed a word. 'There are NO settings . .. '
Hi Joseph,
To complement Mark's answer, DTM - Terrains are 2,5 surfaces and are not appropriate to model more complex surfaces with caves or overhangs.To effectively model such surfaces, I had tested successfully 2 worflows depending on available data/Software:
In both cases you will get a mesh you will be able to assign a Feature definition to, then target or compute quantities from.
HTH
Vincent RAULT [Bentley]
Hi Vincent, I'm running into an issue where I believe I need to assign a feature definition to a 3D mesh as you describe above; I'm trying to take the subsurface data integrated from gINT to update my quantities by the material type being excavated. We've constructed 3D meshes, but I'm not finding any options to apply a Feature Definition to them... I'm also not finding much info on this workflow, beyond sales pitches saying it can be done. Let me know if you have any advice on this.
Thanks,
Joseph
To assign a feature you need to use the "Set Feature Definition" tool
Then choose "Mesh".I'm sure there is a SIG that covers similar workflow, will try to find something.