64 lines
3.8 KiB
Markdown
64 lines
3.8 KiB
Markdown
LimboAI - Behavior Trees and Hierarchical State Machines for Godot Engine 4
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---
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LimboAI is a C++ module for Godot 4 that provides an implementation of Behavior Trees and State Machines, which can be used together to create complex AI behaviors.
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>**🛈 Supported Godot Engine: 4.1**
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>**🛈 License**: Use of this source code is governed by an MIT-style license that can be found in the LICENSE file or at https://opensource.org/licenses/MIT.
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## Features
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- Behavior Trees (BT):
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- Use the `BTPlayer` node to execute `BehaviorTree` resources.
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- Easily create, edit, and save `BehaviorTree` resources within the editor.
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- Combine and nest tasks in a hierarchy to create complex behaviors.
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- Control the flow of execution using composite, decorator, and condition tasks.
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- Write your own tasks by extending core classes: `BTAction`, `BTCondition`, `BTDecorator` and `BTComposite`.
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- Built-in class documentation. Check out the `BehaviorTree` and `BTTask` class documentation to get started.
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- Utilize the `Blackboard` for seamless data sharing between tasks.
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- Use the `BTSubtree` task to execute a tree from a different resource file, promoting organization and reusability.
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- Blackboard scopes separate namespaces of variables from subtrees, and enable advanced techniques like sharing data among agents in a group.
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- Visual Debugger: Inspect the execution of any BT in a running scene to identify and troubleshoot issues.
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- Evaluate the performance of your trees with custom performance monitors.
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- Hierarchical State Machine (HSM)
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- Extend `LimboState` class to implement state logic.
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- `LimboHSM` node serves as a state machine that manages `LimboState` instances and transitions.
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- `LimboHSM` is a state itself and can be nested within other `LimboHSM` instances.
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- 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.
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- Combine state machines with behavior trees using `BTState` for advanced reactive AI.
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- Delegation: Instead of extending `LimboState`, utilize vanilla `LimboState` and delegate implementation to provided callback functions. Perfect for game jams and quick prototyping.
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- 🛈 Note: Currently, state machine transition setup and initialization must be done through code as there is no GUI editor for state machines at the moment.
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## Compiling
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> 🛈 Precompiled builds are a WIP
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To incorporate this module, you'll need to build Godot Engine from source with LimboAI module included.
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Building From Source:
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- Download the Godot Engine source code and put this module source into the `modules/limboai` directory.
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- Consult the Godot Engine documentation for instructions on [how to build from source code](https://docs.godotengine.org/en/stable/contributing/development/compiling/index.html).
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- If you plan to export a game utilizing the LimboAI module, you'll need to build export templates as well.
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## Contributing
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All contributions are welcome! Feel free to open issues with bug reports and feature requests, and submit PRs.
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## Roadmap
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Features and improvements that may be implemented in the future:
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- Providing precompiled builds for download.
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- Creating a non-trivial demo project to showcase the capabilities of LimboAI.
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- Exploring the execution history of Behavior Trees in the Visual Debugger.
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- Tests and CI.
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- Expanding the library of tasks that can be optionally included in the build.
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- Implementing an ignore list for tasks that users may want to hide in the task panel.
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- GUI editor for state machines.
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- Supporting GDExtension in the future, once it matures.
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