UE5-Modular-Game-Framework/docs/blueprints/08-weapons/77_BPC_RecoilSystem.md

BPC_RecoilSystem — Actor Component

File: Content/Framework/Weapons/BPC_RecoilSystem Parent Class: UActorComponent Dependencies: DA_WeaponData, BPC_FirearmSystem, BPC_CameraStateLayer

Purpose: Handles procedural recoil: camera kick, recovery curve, and ADS recoil reduction. Works with BPC_FirearmSystem to apply per-weapon recoil patterns.

---

Variables

Name	Type	Description
RecoilPattern	CurveVector	Per-weapon kick pattern (X=pitch, Y=yaw)
RecoverySpeed	Float	How fast camera returns to rest
ADSRecoilMultiplier	Float	Recoil reduction while aiming (0.3-0.7)
CurrentRecoilOffset	Vector2D	Accumulated recoil offset
bIsRecovering	Bool	Recovery in progress

Functions / Events

Name	Inputs	Outputs	What it does
ApplyRecoil	ShotCount: Integer, bADS: Bool	—	Applies recoil kick based on weapon pattern
ResetRecoil	—	—	Clears accumulated offset
TickRecovery	DeltaTime: Float	—	Lerps CurrentRecoilOffset back toward zero
SetRecoilPattern	Pattern: CurveVector	—	Loads per-weapon recoil data from DA_WeaponData

Blueprint Flow

[FirearmSystem fires] -> ApplyRecoil(shotCount, bADS)
  -> Look up RecoilPattern value at shotCount index
  -> Apply ADSRecoilMultiplier if bADS
  -> Add to CurrentRecoilOffset
  -> Push offset to BPC_CameraStateLayer
  -> Start recovery timer on tick

Communications With

Target System	Method	Why
BPC_FirearmSystem	Direct call from ApplyRecoilRequest	Receives fire events
BPC_CameraStateLayer	Direct ApplyFOVModifier	Camera kick application

Reuse Notes

• RecoilPattern is a CurveVector from DA_WeaponData — swap per weapon
• For hitscan weapons, call ApplyRecoil on every shot. For projectile, call on fire release
• Recovery runs on tick when bIsRecovering; disable tick at rest for performance

---

Manual Implementation Guide

Class Setup

1. Create Blueprint Class: Parent = ActorComponent, Name = BPC_RecoilSystem
2. Attach to BP_RangedWeapon or Player Character
3. ⚠️ Local only — recoil is cosmetic, not replicated

Variable Init (BeginPlay)

Event BeginPlay
  ├─ Set CurrentRecoilOffset = (0, 0)
  ├─ Set bIsRecovering = false
  ├─ Read RecoilPattern from DA_WeaponData
  └─ Cache: BPC_CameraStateLayer (from Player)

Function Node-by-Node

ApplyRecoil(ShotCount: Integer, bADS: Boolean) → void

Step 1: Sample RecoilPattern curve at ShotCount (or accumulated counter)
Step 2: Get curve output: Pitch = X channel, Yaw = Y channel
Step 3: If bADS: Pitch *= ADSRecoilMultiplier, Yaw *= ADSRecoilMultiplier
Step 4: CurrentRecoilOffset.X += Pitch, CurrentRecoilOffset.Y += Yaw
Step 5: Push to camera:
  BPC_CameraStateLayer.AddControllerPitch(Pitch)  ← or PlayCameraShake
  BPC_CameraStateLayer.AddControllerYaw(Yaw)
Step 6: Set bIsRecovering = true
Step 7: Set Timer (0.05s loop) → TickRecovery  ← timer runs while recovering

TickRecovery(DeltaTime: Float) → void

Step 1: CurrentRecoilOffset = Lerp(CurrentRecoilOffset, Vector2D(0,0), RecoverySpeed * DeltaTime)
Step 2: If CurrentRecoilOffset nearly zero (< 0.01):
  ResetRecoil()
  Clear Recovery timer

Build Checklist

• Create BPC_RecoilSystem, attach to Player
• Create RecoilPattern CurveVector per weapon (X=pitch, Y=yaw)
• Implement ApplyRecoil with curve sampling + ADS multiplier
• Implement TickRecovery with lerp toward zero
• Wire to BPC_FirearmSystem.OnFire
• Test: fire weapon → camera kicks up → recovers to center