MP_CombatSystem (Meme_Fight)

MP_CombatSystem is a highly scalable, Arkham/Spider-Man style freeflow combat architecture developed for the Meme_Fight project in Unreal Engine 5. Built heavily on C++, the Gameplay Ability System (GAS), and the Environment Query System (EQS), it features a dual-layer AI decision pipeline. The "Macro" brain utilizes an event-driven Behavior Tree with a dynamic Threat Matrix to seamlessly swap targets between Players and NPCs, while the "Micro" brain relies on a Component-based Combat Director to manage attack pacing via a mathematically optimized Token System. The system boasts zero race conditions during multi-faction brawls and extreme CPU efficiency achieved through Debounce/Dirty-Flag patterns.

Technologies Used

Unreal Engine 5C++Gameplay Ability System (GAS)Behavior TreesEQSAI Perception

Game Info

In Development

Genre: Action RPG, Brawler, Development Framework

March 2024

Team Size: 1

Role: Lead Combat Systems Engineer

Engine: Unreal Engine 5.3

Platforms

PCConsole

Gallery

youtube

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Demonstration of the Combat Director pacing and smart dodging mechanics

Gameplay

Core Mechanics

Freeflow Melee

Smart Directional Dodging

Dynamic Threat Swapping

Token-based AI Pacing

I-Frame Management

Game Modes

Single Player

Player + NPC Team Fights

AI vs AI Free-for-all

Difficulty

Dynamic

Key Features

Freeflow combat pacing managed by a decentralized Combat Director component

Dual-layer AI architecture separating Target Choice (Macro) from Attack Permission (Micro)

Smart directional dodging with real-time vector math and wall-collision raycasting

Highly optimized, event-driven Behavior Trees utilizing stacked Decorators to eliminate CPU polling

Dynamic Threat Matrix allowing AI to seamlessly swap targets (Player vs. NPC) mid-fight

Debounce-optimized token distribution algorithm that scales elegantly to 50+ simultaneous enemies

Universal HitReact system triggered dynamically via GAS Gameplay Events

Exclusive Registration (Handshake Protocol) eliminating ghost tokens and AI race conditions

Technical Challenges

Technical Challenge 1

Problem:

Preventing AI token race conditions in massive multi-target (Player + NPC) brawls

Solution:

Designed an Exclusive Registration "Handshake" where AI pushes to a specific Director, isolating arrays

Result:

Flawless multi-target engagement with zero ghost tokens or conflicting AI commands

Technical Challenge 2

Problem:

Optimizing CPU load when 50+ enemies simultaneously request attack permissions

Solution:

Implemented a Debounced "Dirty Flag" event system to replace constant Tick checking

Result:

Eliminated O(N^2) combinatorial explosion, maintaining buttery smooth frame rates

Design Challenges

Design Challenge 1

Problem:

AI getting stuck running to outdated coordinates when the player lunges or dodges away

Solution:

Created custom stacked BT Decorators to instantly abort and recalculate movement upon target displacement

Result:

Highly aggressive, responsive AI that dynamically tracks movement without whiffing

Design Challenge 2

Problem:

Avoiding "shameless" attack token granting that ruins cinematic combat pacing

Solution:

Separated the EQS positioning (Donut) from the Attack phase using a strict Wait-For-Token Decorator

Result:

Polite, cinematic "Kung Fu movie" enemy spacing and attack rhythm

Results Achieved

Architected a highly scalable, AAA-ready C++ combat foundation

Successfully decoupled AI logic from static level triggers to an organic Perception/Threat model

Integrated GAS seamlessly for damage, hit reactions, and invincibility frames

Achieved dynamic, logic-driven target swapping mirroring industry-leading action titles

What I Learned

Mastery of Event-Driven Behavior Tree architecture (Decorators over Services)

Advanced Gameplay Ability System (GAS) integration for modular combat mechanics

Managing highly optimized data synchronization between C++ micro-managers and AI macro-brains

Utilizing mathematical dot products and cross products for spatial awareness and dodging

Development Journey

Foundation: GAS base abilities, Melee Traces, and universal Hit Reacts

AI Pacing: Engineering the Combat Director Component and EQS Donut math

Defensive Mechanics: Smart directional dodging with vector math and I-frames

Architecture Shift: Upgrading to dynamic Threat Evaluation and multi-Director support

Optimization: Implementing Debounce patterns and Decorator-driven BT logic to finalize the AAA loop