Editing solids and planes

Hi

I am converting a meshed model to surfaces and polisurfaces. To do so I used the mesh to nurb command and then the merge surfaces command.

I still have some irregular surfaces (diagonal) that I am exploding , deleting and creating the surface again. is there a way to join them and delete the diagonal line that joins the surface? Also hoy can I ad points and surfaces to an existing surface?

Thanks

Without a specific example, it’s hard to know.
My guess is since you are starting with planar facets, there need to be a flat ridge so Rhino is making a surface edge.
There is no such thing as a smooth mesh.

MergeSrf will combine untrimmed surfaces. InsertControlPoint, InsertKnot, Rebuild and ChangeDegree are a few options for adding ctrl pt info to an existing srf. Mesh to NURBS is not a great way to reverse engineer a mesh though as you’ll end up with lots of tiny surfaces. It’s better to draw curves snapping to the verts on the mesh and then make surfaces from those. There are plugins to help speed this process listed here if you do it often.
http://www.rhino3d.com/resources/