Terrain Mesh Manipulation - Trimming, simplifying, and changing form


I’m trying to find a way to manipulate a terrain in Rhino. I have a mesh that’s been imported as a DWG from Minesight. The first thing I’m trying to do is to clip the terrain mesh. I’ve tried to split/trim/booleandifference the mesh with an extruded curve as the cutting surface and nothing has worked. Say I want to trim the terrain model into a circle, any suggestions on how to go about that?

The second thing I’d like to do is simplify the mesh so that I can work on it in Sketchup. The ultimate goal of this exercise is to be able to manipulate the landform into a different shape. Is there a way to do this? I know how to alter terrains using sandbox in Sketchup but Sketchup crashes with complex files so I haven’t been able to find a way to do this in Rhino OR Sketchup for this file.

So the final question is whether there’s a way to manipulate the terrain in Rhino, similar to the ‘Sandbox’ tools in Sketchup (ie. Smoove, Stamp, Add Detail etc.)

Please let me know if you require more information, I would really appreciate any help with this.

Hello - what does the Check command say about the mesh?


Hello - try moving the mesh close to the World origin and then MeshSplit.