Tips and notes

• The two types of extension can produce very different results.

• The Merge option creates a multi-knot at the connection point for Linear extensions. Curves with multi-knots may not be usable as construction curves, and CAD packages cannot import them.
  

Extend Object Options

Extend Type

Linear – Extend the curve or surface in a straight line.

Because this extension is linear and has no curvature, there is usually a curvature discontinuity at the point or edge where the geometry was extended.

Extrapolate – Extend the curve or surface with the same rate of change in curvature as at the endpoint or edge.

This option produces the smoothest and most seamless extension without adding any edit points to the original surface.

Tip

To fix rough rendering that may result, increase the subdivisions in Render > Editors > Render Stats.

Merge

Merge the extended part with the original surface to form one object. It is turned on by default.

Chain Select

If this option is checked, you can select a series of tangent continuous surface edges by clicking any one of them.

Distance

Default length of the extension when it is first created.

Distance is expressed in the current linear units, and is originally set to 0.0.