Body part design problems

Rear hood.3dm (948.1 KB) Good day all. I’m new to 3D modeling and having problems converting the attached design from polygon mesh to a solid. What is wrong with this mesh and how can I transform the part to a solid surface. I need to mill the part to make a “plug” for molding. Can anyone please assist me

It’s not that simple, you can’t just automatically convert mesh to NURBS solid in Rhino (or any other NURBS modeler for that matter):

Hi Ricardo. Thanx for the info and rapid response. Ok, now this is going to sound dumb, but I have no experience with any 3D modeling. I do not have the basic shape than the attached model. Can I keep the edge, delete the inner polygons and then create a NURBS solid, or how can I design the shape?

With t-splines you can. Within certain limitations.

Cheers, Norbrt

(Plug-in for Rhino) T-Splines’ Retopology tool comes to mind for a task like this. Here’s the workflow:

The Retopo process allowed a surface to be created from a rough OBJ mesh.

From there, the T-Splines surface was easily tweaked and massaged. One-click converts a copy into a Rhino Nurbs polysurface thus allowing me to go back and make variations on the T-Splines model.

Without the plug-in, I’d suppose one possible way to do this in Rhino is project curves onto certain key areas of the mesh and use lofting or surface-from-edge commands.