Available since LÖVE 0.9.0  
 This function is not supported in earlier versions. 
Gets the child indices of the shapes of the two colliding fixtures. For ChainShapes, an index of 1 is the first edge in the chain.
Used together with Fixture:rayCast or ChainShape:getChildEdge.
indexA, indexB = Contact:getChildren( )
None.
number indexAnumber indexB
    © 2006–2016 LÖVE Development Team
Licensed under the GNU Free Documentation License, Version 1.3.
    https://love2d.org/wiki/Contact:getChildren