If anyone's missed it, here's the official announcement for X4: http://www.egosoft.com/games/x4/info_en.php

If we're to believe the hype, it's going to be a direct continuation of the unique blend of elements that made the X3 games the flawed yet shining jewels of the series, "borrowing" some of the newer elements from X - Rebirth as well, including, of course, the new graphics engine which is going to be tweaked/improved even more for the game.

As a bonus to this announcement I'll just leave this note here: if anyone's interested in a copy of X3: Terran War Pack to play until X4 comes out just send me a chat message or reply to this post and I'll see what I can do*.

*this is a limited stock offer.

Looking forward to see what they will do with it.

Now I have not played Rebirth but what did you not like about its engine? Not talking about gameplay here but how the engine that drives the game works. It is a lot more modern than the X3 engine that is from like 2004 and still used for Albion Prelude from 2011.

Technologically obsolete. It was made for consoles and now have terrible - requirements/quality ratio. IMHO, OFC.

So I looked up the system requirements and they are low. Quite natural it wants a lot of RAM being the type of game it is (recommended RAM is quite high, I admit). It suggests a Radeon HD 4870 with 512MB VRAM as minimum. I have that card as a backup reserve in a closet and it is TEN years old.

It won't use the same engine, they clearly said that much. Maybe they'll reuse bits of the old Rebirth engine here and there, but the new engine is going to use Vulkan for rendering, so they might end up rewriting/developing more than just overhauling. New minimum requirements: Riva TNT2
New recommended requirements: GTX 1080 Ti :P

Hehe!
If they are making a new engine it will indeed probably have much, much higher recommended graphics card.

Don't get me wrong guys, but even the old engine is still looking fabulous. Now just imagine what it could/would be with a even better engine.

But than again on the other hand, what about the megacomplexes? What kind of CPU and GPU would you need to have for those babies? :D

I did have some games/saves with certain sectors were I was not allowed to look even remotely towards my complexes to NOT get a framedrop :D

Compare with another engines in terms of quality and tech features, like CryEngine and Unreal.

Those are not for space economy sims but yes, might be a good thing they are remaking their engine, hopefully better. CryEngine and UnReal have been used and worked on for many years by many games and so they are pretty good now, I guess.

Economy part relies heavily on CPU and RAM (i don't think devs here is able to develop CUDA-compatible mechanisms).
Well, all we can now is wait, will look on what they roll out. Will see.

Wasn't Everspace built in Unreal Engine? (Edit: I just noticed you said space economy sims... which Everspace certainly is not.)

I haven't worked with CryEngine, but I've played around with Unreal Engine a bit. Working in C++ is a nice change from previous Unity work, and as long as you keep the core economy functionality in C++ instead of using Blueprints for it, I don't see any reason why it wouldn't be performant.

Anyway, I have to agree with Goodaltgamer that the older engine still looks great. Actually, I still prefer the appearance of X3AP to Rebirth. The stations in Rebirth always felt a little cartoony to me somehow.

It's a matter of preference, I suppose.

What they're doing with ship and station walking for X4 looks kinda neat (and not as grindy as Rebirth), but I felt (in Rebirth) like the walking around kinda detracted from the rest of what I was trying to do out in space. X3 was far too menu-heavy for some, but I guess I prefer that style of play—then again, I typically play as a manufacturer and trader these days, and menus make up the core mechanics for that style of play.

If they could really make the walking around meaningful, though—something along the lines of Mass Effect 1+2—that would be fantastic (I know, shooting for the moon with that request). They just really need to flesh out the NPC AI and make them feel like real people before I'll see a lot of value in that part of the gameplay.

Not being a programmer I just let my mouth run and maybe I was spewing out BS. I just thought that, while probably possible, it would be too tricky to tweak an existing licensed engine.

I did not understand why they added that station walking part. Pressure from some who wanted the game more alive?

Actually IIRC cytek(?) tried to supply a kind of universal engine for others to use, but funny enough most developers refused to use it. I read long time ago (kind of interview) that they were really disappointed that hardly anyone did pick up on it and instead went for their own engines.

And I must say, I do agree with them. Most other stuff is standardized and you just use the according libraries, but for any reason, instead of putting the resources together, everyone is re-inventing the wheel the whole time.

And tweaking an existing engine: Depends what you want. Most of the time the problem is documentation. Most developers do not want to share everything.....