Melee Combat System

Melee Combat System

Collision Detection Challenges

Before implementing melee combat, understand the collision detection problem: animations and projectiles moving at high speeds can “jump” large distances in a single frame, potentially missing targets. While advanced solutions exist, this implementation uses basic collision systems with awareness of potential limitations.

Basic Melee Setup

Weapon Hitbox Creation

Add collision detection to character for melee attacks:

Right Hand Weapon Hitbox

• Component: Box Collision attached to right hand item socket
• Dimensions: Box extent 10x10x64 (sword-like dimensions)
• Position: Z location 60 to extend from hand
• Collision Settings: Custom collision, ignore all, overlap pawn only
• Default State: Collision disabled (enabled only during attacks)

Hit Detection Implementation

// Weapon Hitbox Overlap Event
OnWeaponHitboxOverlap(OtherActor) {
if (OtherActor != Self) {
Interface_Health_Modify(OtherActor, Subtract, 25);
}
}

Kick Hitbox Setup

Some attacks use kicks rather than weapon strikes:

Foot-Based Collision

• Component: Box Collision attached to right toe base socket
• Dimensions: Box extent 16x16x32 for foot coverage
• Position: Z location -24 to align with foot
• Same Collision Settings: Custom collision, overlap pawn only

Timing Control System

Montage Notify Events

Control exactly when damage occurs during animations:

Montage Notify Setup

1. Timeline Positioning: Place timeline where attack should deal damage
2. Add Notify: Right-click timeline > Add Notify > Montage Notify
3. Notify Names: “melee_on” to enable damage, “melee_off” to disable damage

Notify Implementation

// Montage Notify Handler
OnNotifyBegin(NotifyName) {
if (NotifyName == 'melee_on') {
set_damage_variable;
enable_weapon_collision;
} else if (NotifyName == 'melee_off') {
disable_weapon_collision;
clear_hit_actors_array;
}
}

Hit Prevention System

Ignore List Implementation

Prevent multiple hits on same target during single attack:

Hit Actors Array

• Variable: Hit_Actors array to track damaged targets
• Add Unique: Only add each actor once per attack
• Pre-Check: Verify actor not already in array before dealing damage

// Hit Prevention Logic
OnWeaponHitboxOverlap(OtherActor) {
if (OtherActor != Self) {
if (!Hit_Actors.Contains(OtherActor)) {
Interface_Health_Modify(OtherActor, Subtract, Damage_Variable);
Hit_Actors.AddUnique(OtherActor);
}
}
}

Array Management

• Clear Array: Reset hit actors array when collision disables
• Attack Reset: Clear array for each new attack cycle

Damage System Integration

Variable Damage System

Allow different attacks to deal different damage:

• Damage Variable: Float variable set before each attack
• Flexible Values: Different attacks can set different damage amounts
• Interface Integration: Use existing health modification system

Melee Functions

Consolidated Melee Function

Create reusable function for all melee attacks:

F_Melee_Damage Function

• Input: Other Actor (target of attack)
• Self Check: Verify not attacking own character
• Damage Application: Use damage variable for flexible damage amounts
• Hit Tracking: Manage hit actors array

F_Melee_Collision Function

• Input: Notify Name, Weapon Boolean, Damage Amount
• Collision Management: Enable/disable appropriate hitbox
• Timing Control: Respond to montage notify events
• Hitbox Selection: Choose weapon hitbox or kick hitbox based on weapon boolean

Multiple Hitbox Support

Support different attack types:

• Weapon Attacks: Use weapon hitbox attached to hand
• Kick Attacks: Use kick hitbox attached to foot
• Function Parameter: Boolean to select appropriate hitbox

Polish and Integration

Animation Integration

Add melee notify events to all attack animations:

• Precise Timing: Place notify events at exact moment of impact
• Multiple Hits: Some animations may have multiple melee_on/melee_off pairs
• Copy/Paste: Use copy/paste to ensure consistent notify naming

Testing and Refinement

• Hit Registration: Verify all attacks register hits properly
• Double Hit Prevention: Confirm no double-hits occur
• Range Testing: Ensure hitboxes feel appropriate for visual attacks
• Performance: Monitor for any performance issues with collision

The melee combat system provides responsive, timing-based combat with proper hit detection and prevention of exploitation while maintaining visual consistency with attack animations.