Graphics Programs Reference
The dialog box for the tool has one unique feature that you haven't encountered
yet: you can select either a face (or several faces) or a quilt. A quilt is a number of
surfaces that are tangent to one another and that form a continuous surface.
Defining the Clearance Envelope
For your design, you'll create an offset surface that defi nes the clearance for the
hole in the sheet metal:
1. Start the Thicken/Offset tool found in the Surface panel of the
2. Set the Output option to Surface, and set Distance to .35 .
3. Select the surfaces you copied into the duct, as shown in Figure 7.47.
FIGURE 7.47 Offsetting surface to create a clearance model