Mesh to surface


I have a mesh which I am trying to convert to a surface. Does anybody know how I can convert it in Grasshopper or Rhino? I am able to convert it to a polysurface, but I need a surface. The polysurface also consists of a lot of surfaces, so I am unable to easily convert the polysurface to a surface.

Use quad remesh and enable convert to subD.
After that you can convert subD to nurbs surfaces with packed faces.