Unreal Engine project demoing a Performant Projectile System, from my Optimization for Game Programmers (What every Game Programmer should know about Performance) talk.

This project has two kinds of projectiles, one using the built in ProjectileMovementComponent with an Actor, and another one written from scratch in a ProjectileSubsystem, called Actorless. The projectiles simply move through the world at a constant velocity and destroy themselves when they impact something. A spawner will keep spawning projectiles if they were destroyed to keep a consistent amount of projectiles alive.

The Actorless projectiles are designed to utilize the CPU cache, prefetcher and branch predictor in order to achieve a good baseline performance. The projectile states are just stored in a struct, inside an array (SoA), compared to Actor/Components that are all heap allocated.

It's important to note, I did NOT optimize the Actorless projectiles. This is literally just the first thing I typed into the code editor. By just understanding how the hardware works, and designing our code around that we get a 10x speedup. The Actorless projectiles can be easily optimized with Multithreading or SIMD.

There should be a BP_ProjectileConfig in the Content Explorer. This is how you configure the projectiles to spawn. You can add more of these configs by adding another AProjectileSpawner into the world.

Then you can run Unreal Insights. Make sure to disable Debug Drawing inside of the Config files to get more accurate performance results.