AI fixed Unreal Engine bugs that went unsolved for ten years. Epic Games is thrilled

Epic Games is actively integrating AI into Unreal Engine development: neural networks have already helped fix bugs that had been piling up for ten years and accelerate engine optimization.

Two weeks ago, Epic Games CEO Tim Sweeney announced a massive shift toward artificial intelligence tools. Now, Unreal Engine 5 Technical Director Marcus Wassmer revealed in an interview that company employees are actively using Claude Code and Codex.

According to him, AI has already helped eliminate bugs that engineers had been wrestling with for a decade, sped up shader compression, and reduced the size of updates. In addition, neural networks helped rewrite a significant part of the D3D12 rendering layer. Work that would have taken a single engineer six weeks took only one week, while simultaneously improving CPU load and reducing the number of errors.

Wassmer also stated that Epic Games programmers have almost entirely switched to “vibe coding”: instead of writing code on their own, they primarily supervise and refine the results generated by AI.

The potential of this new approach remains to be seen in Unreal Engine 5.9 and especially Unreal Engine 6. Currently, UE5 faces regular criticism for poor performance and visual instability.