Function GridGraph.NearestNodeDistanceSqrLowerBound

float NearestNodeDistanceSqrLowerBound (

Vector3	position	The position to check from
NNConstraint	constraint	A constraint on which nodes are valid. This may or may not be used by the function. You may pass null if you consider all nodes valid.

)

Lower bound on the squared distance from the given point to the closest node in this graph.

This is used to speed up searching for the closest node when there is more than one graph in the scene, by checking the graphs in order of increasing estimated distance to the point.

Implementors may return 0 at all times if it is hard to come up with a good lower bound. It is more important that this function is fast than that it is accurate.