Explanation on Behavior Tree's Decorator of Blackboard Condition : Notify Observer's "On Result Change" vs "On Value Change"?


Would there be any clear explanation on Behavior Tree’s Decorator of Blackboard Condition : Notify Observer’s “On Result Change” vs “On Value Change”?


Let’s say you have a key in blackbord that stores an Actor instance. You may want the Blackboard observing decorator to react (abort active task) when your condition changes (in this case “is or is not NULL”) or you might want it to react when the observed value changes, like it was set to ActorA and not it stores ActorB. The first one is “On result change” the second one “On value change”.



What if, for example, I have a decorator set to “On value change” and I have my key query set to “Is Equal to” and my key value is enum “0”. Does this mean it will abort whenever it’s NOT “0” or will it abort when ever it changes from equal to “0” to not equal to “0” and vice versa.