Unreal Fest 2025 kicked off with an impressive demonstration of how The Witcher 4 developers CD Projekt Red are getting to grips with Unreal Engine 5. The 14-minute tech demo features lush forest landscapes, detailed character rendering and impressive hardware RT features, all running at 60fps on a base PlayStation 5. It’s one of the most visually ambitious projects we’ve seen for current-gen consoles even at this early stage, and we wanted to learn more about how the demo was created.
To find out, Digital Foundry’s Alex Battaglia took a trip to CDPR’s offices in Warsaw and spoke to key figures at CD Projekt Red – including Charles Tremblay, VP of technology; Jakub Knapik, VP of art and global art director; Kajetan Kapuscinski, cinematic director; Jan Hermanowicz, engineering production manager – as well as Kevin Örtegren, lead rendering programmer at Epic Games.
A selection of questions and answers from the interview follows below. As usual, the text has been slightly edited for clarity and brevity. You can see the full interview via the video embedded below. Enjoy!
When did the cooperation between CDPR and Epic begin for The Witcher 4 tech demo, given the announcement of The Witcher going to Unreal in 2022?
Jan Hermanowicz: That will be about three years by now. When it comes to this particular demo, it’s sometimes hard to draw a line, but this is a relatively fresh thing that we started working on somewhere last year.
Why did CDPR switch from RedEngine to Unreal Engine in 2022?
Charles Tremblay: I get this question often, and I always preface it by saying that I don’t want people to think the tech we had was problematic – we’re super proud of what we achieved with Cyberpunk. That being said, when we started the new Witcher project, we wanted to be more of a multi-production company, and our technology was not well made for that. It was one project at a time, put the gameplay down, then move on. Second, we wanted to extend to a multiplayer experience, and our tech was for a single-player game. So we decided to partner with Epic to follow the company strategy.