Spline Editing Icons

 

Attach Curves; select two curves

Insert Knot; select curve parameter point(s)

Detach Curves

Nurbs surafce; create nurbs square on grid

Attach Surfaces; select isoparms

Detach Surfaces; select isoparms

Open/Close Surfaces

Insert Isoparms; select isoparms

Extend Surfaces

Rebuild Surfaces

Sculpt Geomtery Tool

Surface Editing Tool