Surfacing > Using Technical Surfacing > Creating a Surface Feature > Creating a Feature with an Open or Closed Volume
  
Creating a Feature with an Open or Closed Volume
When creating a surface feature with Extrude, Revolve, Sweep, Helical Sweep, Swept Blend, or Shapes > Blend, you can create a quilt that encloses a closed volume by capping the ends of the feature, or you can leave the ends open.
• To create a surface feature without closing the ends, click the Options tab and clear the Capped ends check box. For example, an extruded circular section creates an open-ended tube with the open ends displayed with yellow edges.
• To create a surface feature with a closed volume, click the Options tab and select the Capped ends check box. For example, an extruded circular section would result in a closed cylinder so all edges of the quilt are two-sided, shown in magenta. Note that the section must be closed for this option.