CDPR announced that their new The Witcher game will be replaced by its own RED engine to Epic Games' Unreal Engine 5. Why did CDPR make the decision to change engines? According to a former employee of CDPR, CDPR wanted to use an engine with a deep foundation, and they didn't want to get entangled in the tools and features of the RED engine for every new game.
Former CDPR employee Bart Wronski explained that every time CDPR develops a new game, they rewrite the RED engine from scratch in the hope of using it better than the last time, but then due to overtime they have to modify it, making it unsustainable or even useless. Considering that this could happen again, CDPR chose an engine with a deep foundation to avoid making the same mistakes again.
"In every game they threw away the entire engine and rewrote it from scratch, hoping that this time it would be better and work, but because of the intensive overtime, it was completely upside down, and now it is impossible to maintain, or even use."
Now they'll do it again, because CDPR doesn't have the Witcher 3 system, so it's better to simply drop it and use an engine with a solid foundation without having to chase its tools and features.
Either way, things like gameplay/open world need to be rewritten. ”
In another tweet, Bart further explained the "rewriting engine from scratch," confirming that many core-level systems from The Witcher 2 to The Witcher 3 were rewritten, and that from The Witcher 3 to Cyberpunk 2077, this happened again, "even the stream, the scripting system, even if everything (well, part of the shader is actually retained) is rewritten." ”