Constructing Splines

A Spline is a smooth curve that is fit to a set of points. You can create a non-uniform rational B-spline or NURBS curve for any number of fit points. You can also fit the Spline to the specified points within a specified tolerance value.

To construct Splines:

1. Click Draw > Spline (or type Spline).
2. In the graphics area, specify the:
   1. Start point of the Spline.
   2. Next fit point of the Spline.
3. Do one:
   • In the graphics area, specify successive points to continue the Spline.
   • Specify the Fit tolerance option to define a fit tolerance and specify other spline points.
4. To conclude the Spline, do one:
   • Press Enter and click in the graphics area to define the tangents at the start and end points of the curve.
   • Specify the Close option to close the Spline curve and click in the graphics area to define the tangent to the curve at the closing point.

  After you specify a fit tolerance, the fit tolerance applies to all fit points until you change it. Setting the fit tolerance to zero forces the Spline to pass through the fit points.

Note: You can use EditPolyLine to convert a PolyLine to a Spline.

Access

Command: Spline

Menu: Draw > Spline