How do you split a mesh with a projected curve?

I’ve project multiple enclosed curves onto a topo mesh and would like to split them with the mesh so I can apply different materials to my topography (i.e., roads, sidewalks, etc.)

When I try to split rhino triangulates more on the outside of my enclosed curves and then splits it from the mesh but not the part I would like split. Is there a way to get a clean split without using a NURB surface? I have a rigid topo with walls and can’t get a NURB surface to accurately represent my topo.

If Rhino isn’t able to split the mesh correctly is there a tool like Google Sketch-up’s drape command in Rhino?


have you tried to use _SplitMeshWithCurve ? If this does not split, you might try to extrude your curves vertically, create a mesh from the resulting surfaces and split by using _MeshSplit. Btw. the creation of triangles near the split location is expected.


Yes, I have tried that as well. The mesh split worked for clipping the boundary of my site (trimming the outer edge of my mesh) but not for splitting meshes that intersect the middle of the mesh.

You might post or send these failing cases to McNeel so it can be fixed. The mesh splitting still needs improvement…