The two newly created Navlinks that are replacing the original Navlink.
The index of the coordinate in which the split takes place and the new navlinks are connected to one another.
The Navlink that will be split.
The relative position on the Navlink's geometry where the split happened. The range of values is from 0.0 to 1.0, where 0 represents the position on the first and 1 on the last coordinate.
The NavlinkSplitHook is called whenever a Navlink is devided into two new Navlinks. ('Navlink.split' operation).