Hey, adding ECS or something ECS-esque wouldn’t require any rewrite of the engine. It certainly didn’t require on Unity: all the old baggage is still there, for better or worse. Like I said, Niagara is 2/3rds of the way into doing what an ECS is supposed to do IMO: updating the state of a large collection of entities in a cache-friendly[FONT=Helvetica,Arial,Verdana,sans-serif] and multithreading-friendly way. If Epic adds some debugging capabilities, the ability to nativize Niagara scripts for CPU and proper ways to get data out from it some crazy stuff could be done.