float The y coordinate of the bottom edge, measured from the lower-left corner of the parent RectTransform's rect. If there is no parent RectTransform, returns the value relative to the element's own rect origin.
Returns the y coordinate of the bottom edge of this RectTransform in its parent's coordinate space.
All four edge-position methods — GetLocalBottom, GetLocalTop, GetLocalLeft, and GetLocalRight — share the same coordinate system, whose origin is at the lower-left corner of the parent rect. Use SetLocalBottom to move the bottom edge to a specific position without changing the element's size.
Additional resources: GetLocalTop, GetLocalLeft, GetLocalRight, SetLocalBottom.