Mirroring in three dimensions

You can create a mirror image of selected entities in three-dimensional space. You mirror the entities about a mirror plane that you define by either specifying three points; selecting an existing two-dimensional planar entity; aligning the plane parallel with the xy, yz, or xz plane of the current UCS; or aligning the plane with the current view. You can delete or retain the original entities.

To mirror an entity about a three-dimensional plane     

   1   Do one of the following to choose 3D Mirror ():

    On the ribbon, choose Edit > 3D Mirror (in Modify).

    On the menu, choose Modify > 3D Mirror.

    On the Modify toolbar, click the 3D Mirror tool.

    Type mirror3D and then press Enter.

   2   Select the entities, and then press Enter.

   3   In the prompt box, choose 3 Points, or press Enter to select the default.

   4   Specify the first point on the mirror plane.

   5   Specify the second and third points on the plane.

   6   In the prompt box, choose one of the following:

    Yes-Delete Entities to delete the original entities.

    No-Keep Entities to retain the original entities.