Dependent curves are curve sub-objects whose geometry depends on other curvesor pointsin the NURBS object. When you change the geometry of the original, parent sub-objects, the dependent curve changes as well.
You create dependent curves using the Create Curves rollout in the Modify command panel for a NURBS curve. (The Point Curve and CV Curve buttons create independent curve sub-objects. Use these as previously described in "Creating NURBS Curves.") The remaining buttons create dependent curves, as described in the sections below.
Tip: Lathe and extrude surface sub-objects can be based on only a single curve (see "Creating Dependent Surfaces," below). If you create dependent curves and then want to use the set of curves (for example, two parents and a fillet between them) as the basis of an extrude or lath surface, first go to the Curve sub-object level and use Join to connect the curves.
These are the toolbox buttons for creating curve sub-objects:
Create an independent CV curve.
Create an independent point curve.
Create a dependent fit curve (as with the Curve Fit button).
Create a dependent transform curve.
Create a dependent blend curve.
Create a dependent offset curve.
Create a dependent mirror curve.
Create a dependent fillet curve.
Create a dependent chamfer curve.
Create a dependent U iso curve.
Create a dependent V iso curve.