Unreal Engine 4 AI Programming Essentials

BT Composites, Task, Decorator, and Service

Tasks are executed by composites. Composites are important because they directly affect the flow control within your Behavior Tree.

Composites come in three forms at the time of writing this: Sequence, Selector, and Simple Parallel. Here's a description of each:

• Sequence: This executes each node, returning success on the last node; however, if any node fails, it will immediately return failure and abort the rest of the leaves.
• Selectors: This executes each node, returning success immediately and aborting the rest of the leaves. If a node returns failure, it continues to only return failure if the last child returns failure.
• Simple Parallel: This executes one task and a subtree at the same time, which allows ...