Offset Volume
Insert
Shell/Offset
Use this command to create a feature by offsetting
the volume of one or more shapes. The required inputs include the shapes
to offset, the offset distance and the ability to define openings if desired.
Optional inputs include the ability to keep the original shape, attaching
and deleting offset attributes to individual faces and removing self intersecting
faces.
Shapes - Select the shapes to offset.
Offset - Specify the offset value. A negative value indicates an internal offset. A positive value indicates an external offset.
Openings - Select which faces if any should be deleted from offset consideration or middle-click to skip this option. These faces will reside in the new feature but will not be offset.
Keep original shapes
Use this option to keep the original shape(s). The original will remain separate features.
Intersections
Use this option to remove self intersecting faces. This option
will also detect disappearing face fillet, fillet corners, and chamfers.
These options require some time to complete depending on part complexity.
Do not remove - Ignore self intersecting faces.
Remove fast - Limited to removing self intersections on or near faces that become completely inverted, such as a fillet that is offset more than its radius. Anything beyond this is not handled.
Remove all - Remove self intersections and inverted regions (including inverted inner loop cases) as well as can be done. Faces that intersect other faces in the shape will be split.
Add Offset
Use this option to attach an offset attribute to a face.
The attribute will govern that face despite the Offset value specified
above. It allows you to control the wall thickness at selected faces independent
of the part's typical wall thickness. 
Select a face.
Specify the offset value. A
negative value indicates an internal offset and positive value indicates
an exterior offset.
Delete Offset
Use this option to delete an offset attribute created with
the Add Offset option above. Select the attribute(s)
to delete.
If you select a shell face to offset and it already has an offset attribute attached to it (i.e., you used the Add Offset option above) and it has not been applied yet, the offset attribute will be applied instead. The offset from this command will be logged into the part's history but will not go into effect unless the offset attribute is deleted and the part is regenerated.
This command could fail if the offset thickness is larger than the radius of the smallest concave fillet on the shape.
