Creates a special object called a shell from a group of surfaces, in preparation for Boolean operations or export to a CAD package.
Turn on this option to use the Maximum Gap Distance from the Preferences > Construction Options as the stitching tolerance. Turn it off to set the tolerance using the Tolerance slider.
Detach the seam of periodic surfaces (that is, closed surfaces such as cylinders and surfaces created with the Revolve tool) before stitching them into a shell.
This option is sometimes necessary when the stitch function does not notice that a surface edge is attached to another edge on the same surface. This is a common problem in CAD systems.
Keep the original surfaces after the shell is created.
Depending on how you set the options, a shell may not match the original surfaces exactly. In this case, unstitching does not produce surfaces that match the originals exactly either; it is a good idea to keep originals. The default is to keep the original surfaces.