Duplicates the current parent’s joint chain across the specified plane. See Mirroring joint chains and Mirror joint chains.
Lets you specify the plane to mirror the joints across, as well as the orientation of the resulting duplicate joints.
Mirror Function
Select one of the following options.
When this option is on, the mirrored joints have the opposite orientation as the original, and the local rotation axis of each joint points in the opposite direction of their counterparts.
This setting is handy for animating opposing movements in a pair of counterpart limbs. For example, if you select a pair of ankles and use the Rotate tool on both at the same time, you can rotate the feet to point symmetrically inward or outward with a single manipulation.
When this option is on, the mirrored joints have the same orientation as the original joints.
With this setting, you can copy animation from one limb to another and get identical behavior. For example, if you want to animate a skier racing down a slope with legs turning in the same direction, use this setting.