The Extend option can be used to trim or extend splines or any curve entity to a point, curve, plane, surface, or by a scalar distance or percent. The parameters by which this is done are controlled through a dialog box that appears when the function is selected. Note that it will be important to follow prompts in the Conversation Bar carefully.

NOTE: If the spline and curve do not intersect when trimming or extending a spline to another curve, the minimum distance routine is used to calculate the nearest point on the target curve to trim or extend to.

Dialog Options:

The following settings are available from the dialog that appears when the function is selected from the Modify Menu.

Extend Curve

Specify whether to extend a curve by a specified distance or by a percentage.

Trim or Extend Curve

Specify whether to trim/extend a curve to a face, plane, curve, or position.

Extension Method

Select an extension method from the available options: Linear or Natural. Linear extensions follow the last tangent vector off the spline in a straight line. Natural extensions use the cubic rate of curvature along the spline to produce a continuous curving extension.

Using the Function

1. Select Extend from the Modify>Spline submenu.

2. The Trim and Extend Curves dialog appears, from which you can specify the trim/extend parameters. Configure the dialog settings where necessary, and select OK to accept any changes.

3. Follow the prompts that appear in the Conversation Bar to complete the editing procedure.

Example Modify Spline Extend: