Increases the level of smoothness for mesh objects by one level.

Button
Ribbon: Home tab
Mesh
panel
Smooth
MoreNot available on the ribbon
in the current workspace
Menu: Modify
Mesh
Editing
Smooth
MoreNot available in menus
in the current workspace
Toolbar: Smooth
Mesh
Smoothing increases the number of facets in the mesh, resulting in a rounder object.

Facets are the underlying components of each mesh face. You can increase the smoothness level up to the value of SMOOTHMESHMAXLEV as long as the number of faces does not exceed the value in the SMOOTHMESHMAXFACE system variable. If you select multiple objects with differing levels of smoothness, their respective levels are increased by one.
You can only smooth mesh objects. However, you have the option of converting some types of objects to mesh during the smoothing operation. You can also filter out ineligible objects that you do not want to convert. For a list of objects that can be converted, see MESHSMOOTH.