BT Graph is a lightweight Behavior Tree system for Unity that combines a visual graph editor with a robust runtime engine.BT Graph is a lightweight Behavior Tree system for Unity that combines a visual graph editor with a robust runtime engine. It allows you to design, debug, and reuse AI logic as data-driven assets instead of hard-coded scripts.With BT Graph, you can quickly prototype behaviors, scale them to complex agents, and keep your gameplay logic readable and maintainable. The built-in Blackboard system enables clean data sharing and runtime binding, while the editor focuses on speed, clarity, and minimal friction.Whether you’re building simple NPC movement or more advanced decision-making systems, BT Graph helps you iterate faster, stay organized, and keep control over how your AI behaves—without heavyweight frameworks or boilerplate code.BT Graph provides a complete, data-driven Behavior Tree solution for Unity, including:Visual Behavior Tree editor based on a node graphTree assets stored as ScriptableObjects (safe to reuse and version)Runtime tree instancing per agent (no shared state bugs)Tick-based execution model (Success / Failure / Running)Manual (code-driven)Multiple tick modes:Update FixedUpdate IntervalLeaf nodes (Actions & Conditions)Built-in node types:Composites (Sequence, Selector/Fallback)Decorators (e.g. Inverter, Repeaters)Expose parameters directly in the InspectorExtensible leaf system:Create custom Action and Condition scripts in C#Runtime bindings per agent via BTRunnerBlackboard system with:Strongly-typed keys (bool, int, float, Vector2/3, GameObject, Transform, etc.)Default values stored in the assetRuntime execution (per-agent instance)Clean separation between:Editor data (tree structure)Blackboard configurationInspector integration for:Node parametersScript assignmentRoot node validation and execution safety checksDesigned for both 2D and 3D projectsNo third-party dependenciesCompatible with Unity 2021 LTS+ (tested with Unity 2022 LTS / Unity 6)
