raytracingfan
Newcomer
The ultimate takeaway is that making seamless open world games is technically challenging no matter what engine a studio chooses. Dragon's Dogma 2 is a great example of how an engine that had excellent performance on titles with constrained maps struggled with an open-world RPG. You need highly-efficient asset streaming and occlusion culling, mechanisms to imperceptibly spawn and de-spawn entities in the game world, NPC AI that can navigate the open-world, simulation logic that gracefully works alongside those mechanisms, etc. It gets even harder if you want a genuine "living, breathing, world", in which case the simulation still needs to handle the behavior of de-spawned entities.
And that's on top of the fact that your QA team and playtesters now spread thin trying to find bugs and performance issues across every single inch of the open world under a variety of different game states and conditions.
