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ESEngine

Behavior Tree System

Behavior Tree is a powerful tool for game AI and automation control. This framework provides a behavior tree system based on Runtime Executor Architecture, featuring high performance, type safety, and easy extensibility.

What is a Behavior Tree?

Section titled “What is a Behavior Tree?”

A behavior tree is a hierarchical task execution structure composed of multiple nodes, each responsible for specific tasks. Behavior trees are especially suitable for:

  • Game AI (enemies, NPC behavior)
  • Alternative to state machines
  • Complex decision logic
  • Visual behavior design

Core Features

Section titled “Core Features”

Runtime Executor Architecture

Section titled “Runtime Executor Architecture”
  • Data and logic separation
  • Stateless executor design
  • High-performance execution
  • Type safety

Visual Editor

Section titled “Visual Editor”
  • Graphical node editing
  • Real-time preview and debugging
  • Drag-and-drop node creation
  • Property connections and bindings

Flexible Blackboard System

Section titled “Flexible Blackboard System”
  • Local blackboard (single behavior tree)
  • Global blackboard (shared across all trees)
  • Type-safe variable access
  • Property binding support

Quick Example

Section titled “Quick Example”
import { Core, Scene } from '@esengine/ecs-framework';
import {
    BehaviorTreeBuilder,
    BehaviorTreeStarter,
    BehaviorTreePlugin
} from '@esengine/behavior-tree';


// Initialize
Core.create();
const plugin = new BehaviorTreePlugin();
await Core.installPlugin(plugin);


const scene = new Scene();
plugin.setupScene(scene);
Core.setScene(scene);


// Create behavior tree
const enemyAI = BehaviorTreeBuilder.create('EnemyAI')
    .defineBlackboardVariable('health', 100)
    .defineBlackboardVariable('target', null)
    .selector('MainBehavior')
        // If health is high, attack
        .sequence('AttackBranch')
            .blackboardCompare('health', 50, 'greater')
            .log('Attack player', 'Attack')
        .end()
        // Otherwise flee
        .log('Flee from combat', 'Flee')
    .end()
    .build();


// Start AI
const entity = scene.createEntity('Enemy');
BehaviorTreeStarter.start(entity, enemyAI);

Documentation

Section titled “Documentation”

Getting Started

Section titled “Getting Started”

Editor

Section titled “Editor”

Advanced

Section titled “Advanced”

Engine Integration

Section titled “Engine Integration”