Results 1 to 2 of 2

Thread: Updating part of an existing 2D mesh with new topographical survey

  1. #1

    Join Date
    Mar 2018
    Posts
    1

    Updating part of an existing 2D mesh with new topographical survey

    I'm a new user of ICM and I'm having difficulty trying to update the 2D zone of an existing model with some new topographical survey data. I'm hoping this is very simple to achieve, I'm just not very familiar with the software yet.

    I have an existing model with detailed Lidar data for the ground model. This Lidar covers the entire extent of the 2D zone. I also have a recent topo survey for a small site within the model extent which has been raised since the Lidar was flown. Is it possible to update the mesh in ICM so that the levels of the raised site are based on this new survey data?

    I have created a ground model TIN of the new survey data and I tried adding a mesh level zone at the raised site but this hasn't worked as I hoped. I only seem to be able to set the elevations of the mesh level zone boundary vertices with an interpolated surface in between therefore I can't represent the full detail of the survey.

    I also tried to create a second 2D zone (one for the raised site based on the new survey and another 2D zone based on Lidar everywhere else) but this also didn't work.

    I've though about trying to merge the Lidar and the new survey into a single ground model dataset, however the Lidar is very large so I'm reluctant to go down that route.

    Any help would be greatly appreciated.

    David

  2. #2

    Updating part of an existing 2D mesh with new topographical survey

    You could try defining two 2D areas, one for the area covered by the LiDAR and one for the area covered by the topo survey, but this might create issues along the edge (also, I dont think you can define 2D areas with holes in them)

    The way I've done this is to delete part of the LiDAR data and substitute the topo survey levels into this area. This does admittedly take some time if the LiDAR area is big.

    To represent the full detail of the topo survey you'll probably need break lines to represent retaining walls/kerbs where levels change instantaneously, and a smaller mesh element size than in the wider mesh may also help. There is a balance here between fidelity and model speed.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •