Create a Projectile Blueprint

Projectiles are Actors spawned by Passives. They travel, collide, deal damage, and optionally apply Buffs.
All projectiles derive from ABaseProjectile.

1. Create the Blueprint

1. In the Content Browser, right-click → Blueprint Class.
2. Search for BaseProjectile and select it.
3. Name it BP_Proj_<YourName> (e.g. BP_Proj_FireBall).
4. Save it in Content/Blueprints/Projectiles/.

2. Components setup

The projectile has three built-in components. Configure them in the Blueprint viewport.

Component	Purpose	What to set
ProjectileMesh	Visual mesh — no collision	Set your mesh and material here. Disable collision on this component.
CollisionComponent	Sphere — handles actual hit detection	Enable collision, set Overlap with relevant channels (characters, walls…).
ProjectileMovementComponent	Handles movement automatically	Adjust InitialSpeed, homing settings here.

3. Movement

Property	Category	Description
InitialSpeed	Stats › Movement	Starting speed of the projectile (units/s). Set to 0 if the projectile should stay attached to the owner (bIsParentedToOwner = true on the Passive).

ProjectileMovementComponent also has MaxSpeed, HomingAcceleration, and bIsHomingProjectile — configure directly on the component.

4. Level-based arrays

These arrays follow the same indexing as passives (one entry per level, 5 entries total).

Property	Category	Description
OnHitDamage	Stats › Damage	Damage per hit. e.g. [10, 15, 20, 25, 30]
Range	Stats › Destruction	Max travel distance before auto-destroy. Leave empty for infinite range.
DurationBeforeDestroy	Stats › Destruction	Max lifetime in seconds. Leave empty for no time limit.

5. Hit behavior

Property	Category	Description
DestroyOnHit	Stats › Destruction	true = destroyed on first hit. false = passes through.
SpawnedActorsOnHit	Stats › Destruction	Array of actor classes to spawn at the hit location (per level).

6. Apply buffs on hit

1. Set ApplyBuffsOnHit = true.
2. Fill the OnHitBuffs array. Each entry is a FBuffArray (array of buff classes) — one per level.

OnHitBuffs[0].Buffs = [BP_Buff_Slow]          (level 1)
OnHitBuffs[1].Buffs = [BP_Buff_Slow]          (level 2)
OnHitBuffs[2].Buffs = [BP_Buff_Slow, BP_Buff_Poison]  (level 3+)
...

7. Visual hit effect (Blueprint event)

Override OnHitEffect(OtherActor) in your Blueprint for visual/sound feedback on impact.
Do not handle destruction here — it is managed by C++.

Example Blueprint graph:

Event OnHitEffect(OtherActor)
  → Spawn Emitter at Location (hit location)
  → Play Sound at Location

8. Link to a Passive

Once your projectile Blueprint is ready, reference it in the Passive's ProjectileBP array.
See Create a Passive.

Complete example — fire ball

BP_Proj_FireBall
  ProjectileMesh              = SM_Sphere  (no collision)
  CollisionComponent radius   = 30
  InitialSpeed                = 1200
  OnHitDamage                 = [15, 20, 25, 30, 40]
  Range                       = [1500, 1500, 2000, 2000, 2500]
  DestroyOnHit                = true
  ApplyBuffsOnHit             = true
  OnHitBuffs[0..4].Buffs      = [BP_Buff_Burn]
  OnHitEffect                 → spawn fire particle