Curving and decurving polylines  

You can convert a multisegment polyline into a smooth curve using either the Fit or Spline option. The Fit option creates a smooth curve connecting all the vertices. The Spline option computes a smooth curve that is pulled toward the vertices but passes through only the first and last vertices. The Decurve option removes Fit or Spline curves and arcs, leaving straight segments between the vertices.    

To fit a curve to a polyline

   1   Do one of the following to choose Edit Polyline ():    

    On the ribbon, choose Edit > Edit Polyline (in Modify).

    On the menu, choose Modify > Edit Polyline.

    On the Modify toolbar, click the Edit Polyline tool.

    Type editpline and then press Enter.

   2   Select the polyline.

   3   In the prompt box, choose Fit.

    4    In the prompt box, choose another option, or choose Done to complete the command.