Features

Behavior Trees (BT)

• Easily create, edit, and save BehaviorTree resources in the editor.
• Execute BehaviorTree resources using the BTPlayer node.
• Create complex behaviors by combining and nesting tasks in a hierarchy.
• Control execution flow using composite, decorator, and condition tasks.
• Create custom tasks by extending core classes: BTAction, BTCondition, BTDecorator, and BTComposite.
• Built-in class documentation. Check out the BehaviorTree class documentation to get started.
• Share data seamlessly between tasks using the Blackboard.
• Blackboard scopes isolate variable namespaces and enable advanced techniques like sharing data between agents in a group.
• Use the BTSubtree task to execute a tree from a different resource file, promoting organization and reusability.
• Visual Debugger: Inspect the execution of any BT in a running scene to identify and troubleshoot issues.
• Monitor tree performance with custom performance monitors.

Hierarchical State Machines (HSM)

• Extend the LimboState class to implement state logic.
• The LimboHSM node serves as a state machine that manages LimboState instances and transitions.
• LimboHSM is a state itself and can be nested within other LimboHSM instances.
• Event-based: Transitions are associated with events and are triggered by the state machine when the relevant event is dispatched, allowing for better decoupling of transitions from state logic.
• Combine state machines with behavior trees using BTState for advanced reactive AI.
• Delegation Option: Using the vanilla LimboState, delegate the implementation to your callback functions, making it perfect for rapid prototyping and game jams.
• 🛈 Note: State machine setup and initialization require code; there is no GUI editor.

Tested

• Behavior tree tasks and HSM are covered by unit tests.

GDExtension

• LimboAI can be used as extension. Custom engine builds are not necessary.