Fuzzy Logic User Guide

🇬🇧 English | 🇺🇦 Українська

Fuzzy Logic is a Mamdani fuzzy inference plugin for Unreal Engine. It lets you describe behavior with readable IF / THEN rules, smoothly blend several conditions, and get one or more numeric decisions without cascades of hard thresholds.

Systems are stored as reusable UFuzzySystemAssets, can run directly inside a UFuzzyLogicComponent, are imported and exported as JSON, are checked by the editor, and are visualized in Slate and UMG.

Fuzzy Logic 1.0, for Unreal Engine 5.8. What's new in this release — Release Notes.

Quick Start

1. Create a Fuzzy System via Content Browser → Add → Miscellaneous → Data Asset.
2. Add an input variable Distance with range 0…2000 and sets Near, Mid, Far.
3. Add an output Aggression with range 0…1 and sets Cautious, Bold.
4. Write the rules:

IF Distance IS Near THEN Aggression IS Cautious
IF Distance IS Far THEN Aggression IS Bold

1. Double-click the Data Asset to open it. On the Inference tab, change Distance on the left and immediately see the Aggression number and graph on the right.
2. Add a Fuzzy Logic component to an actor, assign the created System Asset, call Set Input, then Evaluate Output.

Contents

• Release Notes — what's new, what's fixed, and what to watch for when upgrading.
• Introduction — why fuzzy logic is needed and how to read its results.
• Quick Start — a minimal working system from Data Asset to Blueprint.
• Core Concepts — variables, sets, rules, results, and surfaces.
• Membership Functions — nine built-in shapes and parameter choices.
• Authoring A System — building a robust rule base in a Data Asset.
• Rule Language — the full IF / THEN syntax.
• Inference And Settings — norms, implication, aggregation, and defuzzification.
• Data Asset Editor — Details, Variables, Inference, Compile Log, and JSON commands.
• Blueprint Integration — the component, the library, and the result structure.
• C++ Integration — modules, the inference engine, and extension.
• JSON Presets — two-way exchange, schema, and API.
• Diagnostics And Validation — finding errors in the system and its rules.
• UMG Visualization — plotting graphs in-game.
• Architecture And Performance — caching, threading, and compute cost.
• FAQ — short answers to common problems.
• Demo Content — maps, a separate module, and excluding Demo from the build.
• Fuzzy Drone Arena Demo — a ready-made example with nine agents.
• Fuzzy Turret Defense Demo — a turret defending against drone waves with three chained Mamdani systems.