Mirrors vertex positions dependant on a source geo.

Set Mirror Source: The source geometry needs to be set first, which has to be perfectly symmetrical in object X and the topology needs to be identical to the geometry you want to mirror.

Tolerance defines the threshold for the vertex symmetry match.

Mirror: Performs the mirror on any geometry which has the same topology as the source.

Direction -X is left to right / +X is right to left.

Swop Sides swops the sides.