Cannot join MeshtoNurbs surfaces

CADmapper-Topo-sample.3dm (3.6 MB)

Hi Rhino community,
I had this mesh surface from Cadmapper that I want to transform into a polysurface. No matter how I try to clean the mesh, it all becomes kind of a group of smaller polysurfaces that if I explode, they’ll become tiny pieces.
My goal is when I cut a section, I won’t see those tiny squares.

Thanks for your help.

Hi @nxduyquang9
There’s a couple of ways (at least) to ge there:

  1. Convert the mesh to Sub-D using the ToSubD command
  2. Convert the resulting Sub-D to NURBS using the ToNURBS command


  1. Use the Patch command, making sure that you use sufficient spans to get the result as precise as you need it to be. You’ll probably need to re-trim the resulting pach surface to fit the exact size.

HTH, Jakob