Collision Manager Setup

This guide provides step-by-step instructions for integrating the Collision Manager into an Unreal Engine 5 project, enabling trace hit detection and target selection for weapons and abilities in Action RPGs. Users will learn how to set up the system, add default collision target types to actors, and test core functionality using preconfigured assets. The guide focuses on enabling the system as it functions in the demo content, ensuring developers and designers can quickly implement collision and targeting mechanics.

Prerequisites

• Unreal Engine 5.3 or later.
• Enhanced Input System enabled (default in UE5 templates).
• A pawn Blueprint (e.g., BP_PlayerCharacter) and a weapon Blueprint (e.g., BP_Sword) for testing collisions.
• No additional plugins required.

Integration Steps

1. Migrate the CollisionSystem Folder:

   • In the Unreal Editor, open the demo project containing the Collision Manager.
   • In the Content Browser, locate the CollisionSystem folder.
   • Right-click and select Migrate, then choose your project’s Content directory.
   • Ensure all dependencies (e.g., Blueprints, Animation Notifies) are copied correctly.

2. Add BP_CollisionComponent to Actor:

   • Open your pawn Blueprint (e.g., BP_PlayerCharacter).
   • In the Components panel, click Add Component and select BP_CollisionComponent.
   • In the Details panel of BP_CollisionComponent, add default target types to the DefaultTargetTypes array (e.g., BP_TraceTarget with tag Collision.DefaultTrace) or DefaultTargetTypeMap (e.g., map Collision.SwordTrace to BP_SweepingSocketTraceTarget).

NOTE:

If using with Advanced ARPG Combat System, default collision component target types are configured through the Enemy Info Data Asset and Player Info Data Asset by default for enemies and players

3. Configure Weapon with Default Collision:
   • Open your weapon Blueprint (e.g., BP_Sword).
   • Ensure it has a SkeletalMeshComponent with sockets defined (e.g., StartSocket, EndSocket) for BP_SweepingSocketTraceTarget.
   • In the weapon’s Class Defaults, search for Collision Trace Class and set the default target type for the weapon:

// Class Defaults | Initialization
- CollisionTraceTarget = BP_MyCollisionTraceTarget

• Optionally, in the weapon’s Event Graph, on Event BeginPlay, get the owner’s BP_CollisionComponent and add a default target type:

Event BeginPlay -> Get Owner -> Get Component By Class (Class: BP_CollisionComponent) -> AddCollisionTargetType (TargetTypeTag: Collision.SwordTrace, TargetTypeClass: BP_SweepingSocketTraceTarget, PerformingActor: Self)

• Call SetCollisionProperties to set the weapon mesh and sockets:

 AddCollisionTargetType -> SetCollisionProperties (Mesh: SkeletalMeshComponent, Sockets: StartSocket, EndSocket)

4. Set Up Animation Notify for Melee Collision:

   • Open an attack animation (e.g., Anim_SwordSwing) included in the demo content.
   • Add an ANS_CollisionTrace Anim Notify State to the desired frames where the attack should detect hits.
   • In the Notify’s Details panel, set:
     • Collision Target Tag: Collision.SwordTrace
     • Attack Data: Optional; leave as null to use default trace settings.
     • Trace Radius Modifier: 0 (or adjust for wider/narrower traces).
   • Verify the animation is assigned to an Animation Blueprint used by BP_PlayerCharacter.

5. Configure Enhanced Input for Ability Targeting:

   • In Project Settings > Input, create an Input Action (e.g., IA_TargetAbility).
   • Create an Input Mapping Context (e.g., IMC_Combat) and map IA_TargetAbility to a key (e.g., Left Mouse Button).
   • In BP_PlayerCharacter’s Event Graph, on Event BeginPlay, add the IMC_Combat mapping context:

Event BeginPlay -> Get Player Controller -> Add Mapping Context (IMC_Combat)

• Bind IA_TargetAbility to query targets using FindTargetsByClass:

Enhanced Input Action (IA_TargetAbility) -> Get Component By Class (Class: BP_CollisionComponent) -> FindTargetsByClass (Class: BP_TargetType) -> Store Targets for Ability

6. Test with Default Assets:
   • Place BP_PlayerCharacter in a level with a weapon (e.g., BP_Sword) equipped.
   • Ensure BP_CollisionComponent on BP_PlayerCharacter has a default target type (e.g., BP_SweepingSocketTraceTarget for Collision.SwordTrace).
   • Add an enemy actor (e.g., BP_Enemy) from the demo content to the level.
   • Play the level and trigger the attack animation (via input or ability) to test melee collision; verify hits register (e.g., enemy takes damage).
   • Press the IA_TargetAbility key to test target selection; confirm a target is returned for ability use.

Troubleshooting

• Collisions Don’t Register:
  • Verify BP_CollisionComponent is added to the owning actor (e.g., BP_PlayerCharacter) and initialized with DefaultTargetTypes or AddCollisionTargetType.
  • Ensure BP_SweepingSocketTraceTarget has valid sockets set via SetCollisionProperties.
  • Check that ANS_CollisionTrace uses the correct Collision Target Tag matching the target type.
• Target Selection Fails:
  • Confirm FindTargetsByClass uses the correct BP_TargetType class and the actor has a BP_CollisionComponent.
  • Ensure Collision Object Types and Gameplay Tags to Ignore in the target type are set to include desired targets.
• Animation Notify Not Triggering:
  • Verify the animation is played via the Animation Blueprint and ANS_CollisionTrace is placed on the correct frames.
  • Check that the Collision Target Tag in ANS_CollisionTrace matches the target type tag in BP_CollisionComponent.

Best Practices

• Workflows:
  • Use DefaultTargetTypeMap or DefaultTargetTypes in BP_CollisionComponent to preconfigure common target types for quick setup.
  • Test collision with demo assets (e.g., BP_Sword, Anim_SwordSwing) before integrating with custom animations or weapons.
• Pitfalls to Avoid:
  • Always call DeactivateCollisionByTag for BP_TraceTarget or BP_SweepingSocketTraceTarget to stop tracing and prevent performance issues.
  • Don’t skip setting Performing Actor in AddCollisionTargetType for weapons, as it’s required for correct collision context.
  • Avoid adding BP_CollisionComponent to weapons unless necessary (e.g., projectiles); use the owner’s component instead.
• Performance Considerations:
  • Limit the number of active BP_TraceTarget or BP_SweepingSocketTraceTarget instances by deactivating unused traces.
  • Use Collision Profile Names to Ignore and Actor Classes to Ignore to reduce unnecessary collision checks.
  • Set Draw Debug Type to None in production to disable debug visuals for BP_TraceTarget.