Projectile Types

A projectile type is everything about one kind of ammunition: how it flies, what it damages, how it looks and sounds. Each type is a Mass Entity Config asset built from projectile traits.

All three live in /MassProjectileSubsystem/Types/.

#Create a new type

#Option A — duplicate a shipped type (recommended)

1. In the Content Browser, right-click EC_Projectile_Rifle → Duplicate.
2. Move it into your own folder (for example /Game/Projectiles/EC_Projectile_Sniper) so plugin updates never overwrite it.
3. Open it and change the traits (below).

#Option B — create from scratch

1. Right-click in the Content Browser → Miscellaneous → Data Asset.
2. Pick Mass Entity Config Asset as the class and name it EC_Projectile_<Name>.
3. Open it and, under Config → Traits, press + four times. Set the elements to Projectile Ballistics, Projectile Visual, Projectile Audio and Projectile Surface FX.

Only Projectile Ballistics is required. A type without it cannot be fired, and Register Type Config returns -1.

#Use it

• Pass it as Type Config to Spawn Projectiles / Fire Projectiles, or assign it as Projectile Type on a Mass Projectile Fire component.
• For multiplayer, also add it to Project Settings → Mass Projectile Subsystem → Networking → Replicated Types.

Edits to a type apply the next time the world starts (PIE restart). Types are registered once per world.

#Projectile Ballistics

Flight

Impact

Damage

#Projectile Visual

The type does not own a Niagara asset. It sets the parameters of the shared systems chosen in Project Settings → Mass Projectile Niagara, so a new type costs no new Niagara asset.

Tracer

Smoke

#Projectile Audio

Global rate limits (sounds per frame, minimum interval) are in Project Settings → Audio.

#Projectile Surface FX

A list of Responses, one row per physical surface. This controls what this round looks and sounds like on each material. The physics (does it ricochet?) comes from World Surfaces.

How fallback works: a surface row inherits any empty decal or sound slot from the Default row. If Impact/Exit are empty everywhere, the global Impact Decal Material is used, tinted by the surface's Decal Color. Ricochet decals never fall back to a hole material.

The shipped types use the same two decals on every surface: M_ImpactHoleDecal for Impact/Exit and M_ProjectileBoreDecal for Breach, with Ricochet left empty (bounces leave no mark). For a custom look, create material instances of those two (or your own deferred-decal materials) in your own folder, retint them, and point your rows at the copies.

#Recipe: a sniper round

1. Duplicate EC_Projectile_Rifle → /Game/Projectiles/EC_Projectile_Sniper.
2. Ballistics: Default Speed 95000, Mass Grams 13, Caliber Mm 8.6, Penetration Power 2.0, Max Penetrations 3, Base Damage 90.
3. Visual: Size 8, Trail Segments 4, Trail Time Span 0.12, Smoke Lifetime 4.
4. Audio: a sharper crack, Flyby Radius Cm 900.
5. Add it to Replicated Types (append at the end).
6. Assign it to your weapon.