You're not ignorant, it's an excellent question. The Unreal Engine has a long history, and its origins did not start from a fixed or semi-fixed timestep. The U

You're not ignorant, it's an excellent question. The Unreal Engine has a long history, and its origins did not start from a fixed or semi-fixed timestep. The Unreal Engine doesn't benefit from a variable timestep, it's hampered by it, and the engineers have deemed it too difficult to fix, because the decision permeates the entire engine. There is a "fixed timestep" mode, but it's for cinematics, and specifically for synchronizing the engine with external hardware, IIRC. But it's not a true fixed timestep, it's actually a fixed framerate, instead.