Prevents the specified nodes from being disconnected due to the addition of obstacles.
- iOS 9.0+
- macOS 10.11+
- Mac Catalyst 13.0+
- tvOS 9.0+
A node in the graph.
Another node in the graph to which the node
startis directly connected.
By default, adding obstacles with the
add method disconnects pairs of nodes if the direct path between them intersects an obstacle. This behavior ensures that using the findPathBetweenNodes:toNode: method does not result in a path through the graph that crosses obstacles.
With certain nodes, such as those you add with the
connect method to represent the position of a game character or objective, this behavior might not be desirable. For example, if you add an obstacle that overlaps a character’s current position, the character should be able to find a path that exits the obstacle. In this case, use the
unlock method to protect the connection between the character’s node and a neighboring node from being automatically destroyed. If you later rearrange nodes so that such protection is no longer necessary, use the
unlock method to remove it.