Cad file here

Sorry I forgot to upload the file…
Mesh leaf.3dm (2.1 MB)
Continuing the discussion from Having trouble to efficiently getting a nurbs/ polysurface from this mesh:

Something like the attached - with something this simple, (btw, looks like it was originally a surface object, maybe?) you can

ExtractWireFrame
SelChain > Tangency > Angle at 12-15 to select chains of lines in the web of the wireframe lines.
Rebuild these
Loft

A patch through the internal mesh ‘caps’ will get that surface.
Mesh leaf_PG.3dm (2.3 MB)

Is that enough to go on?

-Pascal

Hi Pascal,

Your Loft surface looks perfect! But mine doesn’t work out as nice as yours… my surface has a lot edge and corner on it…
I did the ExtractWireframe and SelChain out the lines for Loft as you can see in the Lines layer… I used Normal setting when doing the Loft

Mesh leaf.3dm (2.5 MB)

Hi wenJ - I used Rebuild on the curves - they are smooth, not the polylines that come from the wireframe of the mesh.

-Pascal

Ah, that is right. I forgot Rebuild! It works now! Thanks!