Creating Curve Sub-Objects

Curve sub-objects are either independent point and CV curves (similar to the top-level point and CV curves described in Point Curve and CV Curve), or they are dependent curves. Dependent curves are curve sub-objects whose geometry depends on other curves, points, or surfaces in the NURBS object. When you change the geometry of the original, parent sub-objects, the dependent curve changes as well.

• Select a NURBS object. > Modify panel > Create Curves rollout
• Select a NURBS object. > Modify panel > (NURBS Creation Toolbox)
• Keyboard > +T to toggle NURBS toolbox display (Keyboard Shortcut Override Toggle must be on)

You create curve sub-objects using the Create Curves rollout on the Modify command panel for a NURBS curve.

Tip: Lathe and extrude surface sub-objects can be based on only a single curve; see Creating Dependent Surfaces. 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 loft surface, first go to the Curve sub-object level and use Join to connect the curves.

Creation operations for dependent sub-objects require you to select one or more parent objects. In general, you can click and drag, or click and then click again. You can also use the H keyboard shortcut to display the Select Sub-Objects dialog. This is a subset of the Selection Floater for choosing the parent. (The Keyboard Shortcut Override Toggle must be on for H to work this way.)

Toolbox Buttons for Creating Curves

These are the toolbox buttons for creating curve sub-objects:

Create an independent CV curve sub-object.

Create an independent point curve sub-object.

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 chamfer curve.

Create a dependent fillet curve.

Create a dependent surface-surface intersection curve.

Create a dependent U iso curve.

Create a dependent V iso curve.

Create a dependent normal projected curve.

Create a dependent vector projected curve.

Create a dependent CV curve on surface.

Create a dependent point curve on surface.

Create a dependent surface offset curve.

Create a dependent surface edge curve.