Optimizations of bullets, houses and belts :-)

[Rumbleball]

@Gonzi

Thank you very much. So if I were to spawn thousands of bullets (say artillery barrage), the best way would be to ignore actors altogether, create some dedicated structs(FVector3D location, FVector3D velocity), create some optimized lists of them (say linked list), calculate their next position (ideally with threads, maybe things like SIMD, etc) and just give to the Unreal the outcome (say create an instanced mesh and use this for instance transformations)?

Is there some glaring mistake that I would make? Isn’t a singleton-like bullet manager a bad code practice? I am imagining it now as a gun, that asks for some singleton bullet handler to create bullet for it and maybe tell the gun if a bullet hits something.

I sometimes hear people say that singletons are ■■■■ and you should not make stuff like that. I don’t realy know whats their problem, I love them and it clearly states their shall only be this one instance. There might be some problems, e.g. if you want to subclass the manager and exchange the singleton with that subclass can be a bit tricky/impossible.

What you definitly need to take care of is creating new objects. That is pretty expensive cause of all the registration stuff that is going on. Spawning every bullet anew, also means lots of garbage to be collected, which also consumes lots of ressources. What you definitely need is a Object Pool if you still want to use components/actors. You can create that on you own, or use this: Object Pool Plugin in Code Plugins - UE Marketplace (I gues that is what you ment by using a manager)

But yeah, you can also just keep an array or something with bullet information and use a InstancedStaticMeshComponent where you update the instances based on your array or use some custom render code similar to InstancedStaticMeshComponent. You definitely want to do that in C++. Looping over thousands of instance data in Blueprint will crush your performance.