Default UI Menu: Draw/3D Objects/3D Profile Based/Covering

Ribbon UI Menu:

Covering is the process of fitting a NURB surface to a set of outer curve boundaries. Covering compliments existing skinning and lofting tools with a technique often used to fill or close openings in surface models. For controlling the interior surface shape, covering also includes the option to specify guide curves.

To create TurboCAD Cover object:

1. Define the circuit profile. A circuit is a collection of curves, polylines, and arcs (2D or 3D), that form a closed loop. The loop of the profile must not be self-intersecting
2. Define guidelines. These can be points, curves, polylines, or arcs. Guidelines are an optional parameter in the Cover creation process.
3. Select the closed-profile circuit
4. Enable ‘Use Compound Profile’ option (if required) from the Local Menu or Inspector Bar
   
5. Select Finish from the Local Menu or from the Inspector Bar.

In addition, when you select and then display the information about the Covering Object in the Selection Info Palette, there is a "MaxSpans" option which when modified, changes the cover stretch according to the value inserted by the user.