Ah, OK, now I see what you mean, and I definitely agree. The current generation of hardware and rendering tech can certainly produce still images that qualify as almost 100% convincing, but as soon as it starts to move… yeah, it tends to fall apart to a certain degree.
So, back to the future game engine! I’m not an expert in realtime systems by any stretch of the imagination, but I don’t think it will be drastically different from what we have now, just that it would have to run on systems that are way, waaaay more powerful than what we’ve got at the moment.
In terms of “things in motion” generally speaking, we’d have to reach a point where physics simulations can be run at a much higher resolution and precision. Imagine an explosion where every single piece of matter involved can be broken apart into millions of bits, and every one of those bits can be fully simulated, individually, per frame. Imagine a character animation where almost every single fiber in the clothes can be fully evaluated in terms of flexion, elasticity, friction. Every fiber, every frame.
High resolution soft-body simulation of every cubic centimeter of tissue in the character. Every frame.
Then there’s the content creation on top of that. Making a fully convincing human model, for example, is just so seriously time consuming as it is, although there’s a lot of interesting research going on, mostly driven by VFX people working on films, but the same technology applies to games too of course. Still, perfection is expensive.
So, IMHO, this future game engine of yours would have to be ridiculously parallel, and it runs on a machine that has 10 - 100 times the texture memory of today’s cards. It can run billions of physics threads at 60 FPS without breaking a sweat. It can do at least 2-3 bounces of realtime GI on arbitrarily complex surfaces. Nothing would ever be prebaked, everything would be perfectly simulated at run-time.
It shall be named Unreal Engine 12 (at which point the guys at Epic finally drop the “un” prefix in the name) and it will be ready for beta testing in 2031. Early adopters will invest in liquid nitrogen cooling systems for their graphene-based 16384-core Intel processors.