🎬 Demo Video: https://youtu.be/mgm3DgOgP7k
📄 Documentation: https://drive.google.com/file/d/1zQq7I9GMW1FbqhWOxZ_lcH9wKEyET-DF/view?usp=sharing

Interaction System is a lightweight, pure C++ interaction framework for Unreal Engine. Attach a single component to your character, implement one interface on your actors, and your interaction system is ready in minutes.
Built on a Zero Tick architecture — no per-frame polling. Detection runs on Sphere Overlap events combined with a Line-of-Sight trace to ignore objects behind walls. Target selection updates on a timer (default 0.1s), keeping runtime overhead minimal.

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⚡ QUICK SETUP
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1. Add UInteractionComponent to your character

2. Bind TryPressInteract / TryBeginHoldInteract / TryEndHoldInteract to your input actions

3. Implement IInteractable on any actor (or inherit from AInteractableActorBase)

4. Done — no Tick, no boilerplate, no engine modification required

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🔧 FEATURES
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✅ Press & Hold interactions with hold progress callbacks
✅ Sphere Overlap detection + Line-of-Sight trace (ignores occluded objects)
✅ Priority-based target selection with distance tiebreaker
✅ Per-object cooldown support
✅ Zero Tick architecture (timer-based, event-driven — no per-frame polling)
✅ Blueprint-exposed delegates (Target Changed, Started, Completed, Hold Progress, Cancelled)
✅ Fully playable demo level included (Door, Chest, Lever, NPC)
✅ Enhanced Input ready — bind any key, no hard-coded controls
✅ Works with any existing Character or Pawn class

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📦 WHAT'S INCLUDED
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• IInteractable interface — implement on any actor

• UInteractionComponent — attach to your character (Sphere Overlap + LOS)

• AInteractableActorBase — convenience base class with cooldown, priority, hold settings exposed in Class Defaults

• 4 demo actors (C++ + Blueprint): Door, Chest, Lever, NPC

• Demo character (third-person, Enhanced Input)

• UI widgets: Interaction Prompt, Hold Progress Bar, NPC Dialogue Popup

• English & Korean setup guide (PDF)

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📡 DELEGATES
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• OnInteractionTargetChanged — drive your prompt UI

• OnInteractionStarted — trigger animations or sounds

• OnInteractionCompleted(bSucceeded) — handle results

• OnHoldProgressUpdated(ElapsedTime, Duration) — drive progress bar

• OnHoldCancelled — reset UI on interrupt

• OnOpened (Chest), OnLeverToggled, OnNPCTalked — connect your own logic

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🛠 TECHNICAL
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• Pure C++ (no Blueprint-only logic)

• Unreal Engine 5.4 – 5.7

• Platform: Win64

• No third-party dependencies (Enhanced Input plugin required, built into UE 5.4–5.7 and enabled automatically)

• No engine modification required

• Tested on UE 5.4, 5.5, 5.6, 5.7