Extending Curves

You can lengthen a curve by extending one or both of its end points.

Two extension modes are available: Adding segments to the curve and extending in a straight line from the end point.

This task shows you how to:

Before you begin: Open an existing 3D shape containing curves.

Extending Curves Using Handles

You can extend a curve by dragging a handle.

  1. Select the curve(s) to be extended.
  2. From the Edition section of the action bar click Extend .
  3. Use the handles to extend the curve on both sides.
    • Keep segmentation selected: Use the handle to define the curve extension. If the value is positive, the last segment (defined by the arc limits) is lengthened. The distance tag displays the absolute curve distance from the extremity of the original curve.

    • Keep segmentation cleared: The curve is extended taking the curvature continuity of the last segment into account. This means that only this last segment can be extended.

  4. Click OK.

Extending Curves Using Absolute and Relative Distance Modes

You can extend a curve by specifying a distance.

  1. Right-click the distance tag at the curve to open the context menu.

    You can also access the contextual commands by clicking the distance tag and switching sequentially from one option to the other.

  2. Select Edit to enter an extension value.

    This value is always positive.

  3. Select Coupling to apply the delta curve extension to the source handle and the coupling handle.

    A symbol appears next to the coupling handle and its distance tag is displayed in yellow.

  4. Use the handles to extend the second curve.
    Both curves are extended with the same delta. The coupling handle ''follows'' the source handle.

  5. Use Free to free the coupling handle.

If you extend a 3D or 2D curve, the parameterization of the original curve is used, then the extension is calculated. When extending a 2D curve, a 3D cell is added. Therefore the extended curve is made of two or more cells.