Combat & Traversal Prototype

Gameplay Systems Overview

This project focuses on building a responsive third-person traversal and combat experience inspired by parkour-based action games. The systems were implemented in Unreal Engine using Blueprints and designed to interact with one another to create fluid movement and coordinated enemy encounters.

The following gameplay systems were designed and implemented for this project.

AI Combat Coordinator System

System Summary

Implemented a centralized AI combat coordination system that manages multiple enemies engaging the player simultaneously. Instead of all enemies attacking at once, the system evaluates nearby AI, grants attack permission to one attacker at a time, and organizes other enemies into surrounding positions while they wait for their turn.

This creates controlled combat encounters that maintain pressure on the player while avoiding chaotic crowd attacks.

  • Enemy Detects Player

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    Suspicion Meter Fills

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    AI Registers With Combat Coordinator

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    Coordinator Adds AI To Attack Queue

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    Coordinator Selects Current Attacker

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    Selected AI Executes Attack Behavior

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    Attack Finishes

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    Coordinator Selects Next AI

    • Designed and implemented a centralized AI Combat Coordinator

    • Created an attack permission system that selects which AI can attack

    • Implemented an AI queue system for managing waiting enemies

    • Built a suspicion meter that determines when enemies join combat

    • Integrated the coordinator with Unreal Behavior Trees and Blackboards

    • Developed circling behavior for waiting enemies

    • Implemented logic for attack completion and next attacker selection

  • The AI Combat Coordinator acts as a central decision manager for enemies in combat.

    When an enemy detects the player and reaches a suspicion threshold, it registers itself with the coordinator. The coordinator evaluates the list of active enemies and grants attack permission to one AI at a time.

    Other enemies remain active but are placed in a waiting state, where they circle the player and maintain pressure until the coordinator grants them permission to attack.

    This approach prevents enemy overlap while maintaining the illusion of coordinated group combat.

  • Enemy Registration

    When an AI's suspicion meter exceeds a threshold:

    1. AI sends a RequestAttackPermission call to the Combat Coordinator.

    2. The coordinator stores the AI reference in an Active Enemy Array.

    3. If no attacker is currently active, the coordinator selects one.

    Attack Selection

    The Coordinator:

    • Checks if CurrentAttacker is empty

    • Selects an AI from the registered enemies

    • Sets that AI as CurrentAttacker

    • Updates its CanAttack flag

    This flag is read by the AI’s Behavior Tree to enter the attack state.

    Behavior Tree Integration

    AI behavior trees reference the coordinator through blackboard variables.

    Typical flow:

    Selector
    ├── Attack Player (if HasAttackPermission)
    ├── Circle Player (if WaitingForTurn)
    └── Investigate / Chase Player

    The HasAttackPermission value is controlled by the coordinator.

    Circling System

    Enemies waiting for their attack turn move around the player instead of standing still.

    The circling position is calculated by:

    • Getting the player location

    • Generating an offset position around the player

    • Using vector rotation to distribute enemies around the player

    This ensures enemies maintain spacing while remaining threatening.

  • Multiple AI Attacking at Once

    Initially, enemies would attack simultaneously when they detected the player.

    Solution

    Implemented a centralized attack permission system that ensures only one AI can enter the attack state at a time.

    Idle AI Standing Still

    Enemies waiting for their turn felt unnatural when standing still.

    Solution

    Added a circling behavior that generates dynamic positions around the player, allowing enemies to reposition while waiting.

    Combat Flow

    Without coordination, combat encounters felt chaotic and overwhelming.

    Solution

    The coordinator system regulates attack timing and enemy positioning, creating combat that feels intentional and readable for the player.

Directional Melee Combat System

System Summary

Implemented a directional melee attack system that selects different attack animations based on the player's movement input at the moment the attack is triggered. This allows the player to perform forward, backward, and side attacks, creating a more responsive and varied combat system similar to directional melee combat found in modern action games.

The system reads the player's movement input relative to the character's facing direction and determines the correct attack animation to play.

  • Attack Input Pressed

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    Get Player Movement Input

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    Convert Input To Direction

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    Determine Attack Direction

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    Select Corresponding Attack Animation

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    Play Attack Montage

    • Designed and implemented a centralized AI Combat Coordinator

    • Created an attack permission system that selects which AI can attack

    • Implemented an AI queue system for managing waiting enemies

    • Built a suspicion meter that determines when enemies join combat

    • Integrated the coordinator with Unreal Behavior Trees and Blackboards

    • Developed circling behavior for waiting enemies

    • Implemented logic for attack completion and next attacker selection

  • The directional attack system determines which attack animation should play by evaluating the player's movement input relative to the character's forward direction.

    When the player presses the attack input, the system analyzes the current movement input and determines the direction the player intends to attack. This direction is then used to select the corresponding animation.

    Directional inputs are interpreted relative to the character's orientation rather than world direction, ensuring the attacks always match the player's movement relative to their character.

  • Detecting Player Input Direction

    When the player presses the attack button, the system reads the current movement input values.

    1. Retrieve the player's movement input vector

    2. Normalize the vector to determine direction

    3. Compare the direction relative to the character's forward vector

    This allows the system to determine whether the player is attacking:

    • Forward

    • Backward

    • Left

    • Right

    Determining Attack Direction

    The system compares the movement direction against the character’s orientation.

    Example logic:

    • Forward input → Forward attack

    • Backward input → Back attack

    • Left input → Left attack

    • Right input → Right attack

    This allows the attack system to dynamically select different animations based on player intent.

    Animation Selection

    Once the direction is determined, the system selects the correct attack animation.

    Each attack direction corresponds to a specific animation montage section. The system plays the appropriate animation based on the detected direction.

    This allows attacks to feel more responsive and varied during combat.

    Behavior During Combat

    The directional system integrates with the overall combat logic.

    • If the player attacks while moving forward → forward strike

    • If the player attacks while strafing → side strike

    • If the player attacks while retreating → backward strike

    This allows the player to control the type of attack they perform through movement input.

  • Determining Direction Relative to Character Orientation

    Early versions of the system used world direction, which caused attacks to trigger incorrectly when the player rotated.

    Solution

    The system evaluates movement input relative to the character’s forward direction, ensuring attacks always align with the character’s orientation.

    Maintaining Smooth Combat Flow

    Directional attacks initially caused abrupt animation transitions.

    Solution

    Directional attack animations were integrated into the combat animation system to ensure transitions remained smooth and responsive.

🛠Support Gameplay Systems🛠

AI Perception & Suspicion System

System Summary

Implemented an AI awareness system that allows enemies to detect, track, and react to the player based on visibility, distance, and suspicion buildup. The system supports gradual detection instead of instantly alerting enemies, creating a more readable stealth-to-combat flow.

Technical Highlights

  • Line-of-sight detection using trace checks

  • Suspicion meter that increases while the player is visible

  • Blackboard-driven AI state updates

  • Detection threshold that transitions AI from investigation to combat

  • Behavior Tree integration for patrol, chase, and attack states

  • Debug visualization for detection state and suspicion values

Wall Climbing & Mantling Mechanic

System Summary

Implemented a traversal system that allows the player to climb vertical surfaces, align to climbable walls, move along surfaces, and transition into mantle animations when reaching valid ledges. The system was designed to support smooth parkour-style movement while keeping player control readable and responsive.

Technical Highlights

  • Forward trace detection for climbable wall surfaces

  • Wall alignment using impact normals

  • Climb state handling to control movement and input

  • Ledge detection for mantle opportunities

  • Smooth transition from climbing into mantle animations

  • Animation integration for traversal state changes

  • State gating to prevent climbing, vaulting, and mantling from overlapping

Vaulting Mechanic

System Summary

Implemented a vaulting system that allows the player to smoothly move over low obstacles while maintaining forward momentum and responsive traversal flow. The system was designed to make movement feel more fluid while preventing traversal actions from overlapping with other player states.

Technical Highlights

  • Forward trace detection for vaultable obstacles

  • Height checks to validate whether an obstacle can be vaulted

  • Distance checks to ensure the player is close enough to vault

  • Animation montage integration for vault movement

  • State gating to prevent vaulting during attacks, climbing, or other traversal actions

  • Smooth transition back into normal movement after the vault completes

Grapple Hook Mechanic

System Summary

Implemented a grapple hook system that allows the player to target valid surfaces and quickly pull or launch toward them, creating faster traversal options and more vertical movement opportunities. The system was designed to work alongside the existing climbing, mantling, and vaulting mechanics without overlapping player states.

Technical Highlights

  • Trace-based targeting for valid grapple points

  • Surface validation before allowing grapple activation

  • Player launch movement toward the selected target location

  • Rotation alignment toward the grapple direction

  • State gating to prevent grappling during attacks or conflicting traversal actions

  • Smooth transition back into normal movement after reaching the target

  • Integration with other traversal systems such as climbing and mantling

Data-Driven Objective & Scenario System

System Summary

Implemented a quest and objective system that allows the player to receive, track, and complete multiple objectives throughout the prototype. The system was designed to support nonlinear quest progression, allowing objectives to be completed in flexible order while keeping the player updated through the HUD.

Technical Highlights

  • Quest objective tracking through structured quest data

  • Support for multiple active objectives at once

  • Nonlinear objective completion logic

  • HUD updates for active quest progress

  • Objective completion checks triggered by player actions

  • Quest state handling for active, completed, and incomplete objectives

  • Designed to support expandable quest types and future mission content