Game Code Mastery

Targeting System Usage Guide

3 min read

This guide explains how to use the Advanced Targeting System once it is set up. It is divided into sections for key operational and customization tasks, ensuring developers can quickly understand how to interact with and extend the system.

Toggling Lock-On

  1. Ensure the IA_ToggleLockOn Input Action is bound to a key (e.g., “T”) in the Input Mapping Context.
  2. Press the bound key to trigger ToggleLockOn on BP_TargetingComponent. If a valid target is found (based on distance, camera proximity, and line-of-sight), the system locks onto it, and the pawn’s controller rotates to face the target.
  3. Press the key again to disable lock-on.

Switching Targets

  1. While locked on, press the key bound to IA_SwitchTargetRight (e.g., “E”) to trigger Switch To Right, selecting the closest target to the right.
  2. Press the key bound to IA_SwitchTargetLeft (e.g., “Q”) to trigger Switch To Left, selecting the closest target to the left.
  3. The system evaluates nearby targets, updates the lock-on, and triggers the On Target Selected event on the new target.

Creating a Custom Targetable Actor

  1. Create a new actor Blueprint or open an existing one (e.g., an enemy or NPC).
  2. In the Class Settings, add the BP_TargetingInterface to the Interfaces list.

  1. Add a Widget Component to the actor:
    • Set the Widget Class to WBP_LockOn (or a custom widget if desired).
    • Set the default visibility to False.

Note

You can also adjust the position of the targeting dot by clicking on the widget component and moving it in the Character View Port.

  1. Implement the following interface functions:
    • On Target Selected: Use the provided bTargeted bool to set the Widget Component’s visibility (e.g., Visible if bTargeted is true, Hidden otherwise). Add custom logic, such as playing a sound or highlighting the actor.
    • Get Targeting Location: Return the world location of the Widget Component (e.g., using GetComponentLocation) to position the lock-on widget.
    • Can Be Targeted: Return true if the actor is targetable (e.g., check if the actor is alive or meets other conditions). For example, implement logic to return false if the actor’s health is zero.
  2. Ensure the actor’s collision settings respond to the object types specified in BP_TargetingComponent’s Targeting Object Types (e.g., Pawn).
  3. Place the custom actor in the level and test targeting, ensuring the lock-on widget appears and target switching works.

Adding Custom Targeting Widgets

  1. Create a new Widget Blueprint (e.g., WBP_CustomLockOn) in the Content Browser.
  2. Design the widget (e.g., add a custom image or text for the lock-on indicator).
  3. In the targetable actor’s Blueprint, set the Widget Component’s Widget Class to WBP_CustomLockOn.
  4. Ensure the On Target Selected function updates the Widget Component’s visibility.

Customizing Targeting Behavior

  1. Open the pawn’s Blueprint and select BP_TargetingComponent.
  2. Adjust properties in the Details panel:
    • Targeting Distance: Set the maximum distance for valid targets.
    • Rotation Interp Speed: Control how quickly the pawn rotates to face the target.
    • Targeting Object Types: Add or remove object types to filter valid targets.
    • bAutoSelectNextTarget: Enable to automatically select a new target if the current one becomes invalid.
  3. Save and test the changes in-game.

Best Practices

  • Use default targetable actors for quick testing during setup to verify system functionality.
  • Always implement Can Be Targeted to prevent targeting invalid actors (e.g., dead enemies), improving performance and reliability.
  • Test targeting in crowded scenes to ensure the system prioritizes the correct target (closest to camera center).
  • If extending the system, consider adding events in BP_TargetingComponent to notify other systems (e.g., animation or AI) when a target is selected.

Graph View