Combining two mesh consisting of topography


#1

I have two mesh of topography with center point over the same area. One is covering the center area and has higher resolution, one is covering a larger area and has lower resolution. I need to keep the high resoultion in the center so I do not want to merge them, I just want the one with lower resolution to be the borders of the finer one. For further calculations in other programs I can not have two z-values on top of eachother. How do I do that?


(Pascal Golay) #2

Hi Gabriella - try

  • DupBorder on the middle mesh.
  • Pull the resulting curve to the larger mesh
  • SplitMeshWithCurve and delete the inner part if that is successful.
  • Join the high res and the low res mesh with the hole in it.
  • MatchMeshEdge to try to make the edges between the two cleaner - you’ll probably need to try increasing ‘Distance’ settings in that command.

All kinds of stuff can go wrong here but the above is worth a try - you might run Check on the meshes first and make sure they are good meshes from Rhino’s point of view before starting surgery.

-Pascal


#3

Well, you might be able to trim the lower resolution mesh with the border of the higher resolution one. And then again, it might not succeed… Rhino’s mesh trim is not all that reliable.

To try, use DupBorder to duplicate the border of the hi-res mesh, then hide it temporarily. With the border (a polyline) in Top view, run MeshTrim, and pick the low-res mesh on the part to remove.

If the above works, the two meshes will not necessarily match in their vertical dimension along the border. Show the center mesh, save the file, then try MatchMeshEdge to match the two - you may need to increase the maximum tolerance value to get them to match.

–Mitch