The Duplicate Name dialog is displayed if, after you click OK in the Merge dialog, one or more materials to merge have the same name as materials in the open scene.
You can see the updated material name in the “Scene Name” column, while the original name in the source scene appears in the “Source Name” column.
At the right, the dialog displays a duplicate material name. You can edit the name to make it unique before you merge it with the open (current) library by clicking the Merge button.
If you turn this on before you use the buttons, all subsequent incoming materials with duplicate names are treated the same way as the current one, and no further alert messages are displayed.
Use this option when you know that you've got several duplicate materials, and don't need constant reminders.
This checkbox is unavailable if you edit the material name.
Merges the material with the open, current library. This button is unavailable unless you edit the duplicate name to be a different, unique name.
Skips this material and doesn't merge it with the open, current library.
Deletes the "old" material in the open, current library and replaces it with the material to merge.
Click to have 3ds Max automatically rename the material by appending a sequence number to the duplicate material name.
Cancels further merging of materials with duplicate names. If you have already merged some materials, they appear in the open, current library.