You can add pop-up menus to shelf items to perform custom tasks. Pop-up menus appear when you right-click each shelf item.

To create a new pop-up menu

1. Open the Shelf Editor (Window > Settings/Preferences > Shelf Editor).
2. In the Shelves tab, select the shelf you want to add a pop-up menu to.
3. Select the Popup Menu Items tab.
4. Click the New Menu Item button .

   An entry called User menuItem appears in the Menu Items list.

5. Enter a name for the menu in the Rename field.
6. Select MEL or Python in the Menu Item Command panel and enter a script to define the functionality of your new menu.

   Now if you -click the corresponding shelf item, your new menu item appears in the pop-up menu. If you select it, Maya performs the actions defined by the script.

You can modify a script at any time to adjust the functionality of your menu items. You can also adjust the order in which the items appear by reordering them with the Move Up () and Move Down () buttons. You can delete a menu item by highlighting it and clicking the Delete Menu Item ( button.