Check Manifold

The Check Manifold command (from Tools Modeling) enables you to determine whether a selected object encloses a single full space, or has appended surfaces.

On starting the command, you are prompted to select a solid. Click to select the solid you want to check.

As soon as you select the solid, the program displays an alert dialog box containing one of the following messages:

The solid is manifold
   (The solid encloses a single full space and has no appended surfaces)

This solid is open
   (The solid has one or more faces missing)

This solid is multishell
   (The solid consists of one or more separate parts, such as those resulting from a Boolean union operation)

This solid is not manifold
   (The solid has appended surfaces)