NURBS > Refit Surfaces (not for an object with contour patches) regenerates a NURBS surface in selected patches.
When refitting patches, it is important to ensure the selected patches form an ordered array structure. This means the patches must create a logical grid formation with the same number of patches both across and down. This also means the patches must not cross degree-3 corners.
Patches can be refit only once.
Use standard selection tools to select one or more patches, then click NURBS > Refit Surfaces.