Split
Split an edge, split a face, or add an edge loop.
Split Edge
Insert a new vertex along an edge, splitting the edge into two new edges.
This tool is useful when you need to refine the geometry of a PolyNURBS object. Note that this tool permanently modifies the selected object rather than creating a new one, so it does not have construction history.
Split Faces
Split a PolyNURBS face by inserting edges between two points. You can do this to a chain of faces at a time.
Edge Loop
Create an edge loop around the surface of a PolyNURBS.
This tool can only be applied to quad (four-sided) faces. The edge loop is created perpendicular to the selected edge and continues through all quad polygons until it reaches either an open edge or a non–quad polygon.