Use this option to create a symmetrical reflection of the section contour or certain parts of it about the selected axis (vertical or horizontal). Before you generate a contour symmetry drawing, select the direction of the symmetry axis (vertical or horizontal).
Access the option by:
Define the axis location graphically or by entering the vector coordinates in the Mirror dialog.
If Copy is selected, a new object is generated on the other side of the symmetry axis (the original object remains in its place). If this option is cleared, the original object is mirrored to a new place.