Services attach to Composite or Task nodes and will execute at their defined frequency as long as their branch is being executed. These are often used to make checks and to update the Blackboard. These take the place of traditional Parallel nodes in other Behavior Tree systems.
The ComputeDistance service computes the distance between the enemy and the actor contained in the TargetActor Blackboard Key***,*** writing the result in the EnemyDistance Blackboard Key. The service gets called every (interval ± randomDeviation) seconds (both interval and randomDeviation can be set in the node’s details panel)