Epic Games has provided more specific details regarding its adoption of generative artificial intelligence in the development of Unreal Engine and Fortnite. According to Marcus Wassmer, Executive Vice President of Development at Epic, the company is employing tools such as Claude Code and Codex to assist across a wide range of development tasks.
Wassmer highlighted significant recent achievements attributed to AI, including the near-complete elimination of non-deterministic cooking bugs, a persistent issue that has challenged developers for a decade. Additionally, AI has accelerated work on shader compression, leading to substantial reductions in patch sizes. Other notable benefits include the AI-assisted rewrite of a major portion of the D3D12 rendering layer, a task that was estimated to take an engineer three to six weeks but was completed in approximately one week with improved CPU time and fewer bugs. AI has also played a role in maintaining and expanding internal test suites for greater coverage.
In Fortnite, AI has been implemented for automatic monitoring of PC stability, automatic root cause analysis, and automatic fix generation, which has reportedly sped up the resolution of ongoing issues. The engine development has also benefited, allowing for larger architectural refactors than previously feasible due to the extensive file changes required.
Wassmer confirmed that the practice, which he referred to as "vibe-coding," extends beyond the Epic Store launcher preview. He explained that engineers are guiding AI tools to achieve desired architectural outcomes rather than writing the majority of the code themselves. "We’re not ‘one-shotting’ the engine; we’re iterating with AI to ship features developers want and keep the engine within the memory, performance, and scalability envelopes," Wassmer stated.
Epic's proactive approach to AI integration stems from a strategic concern about falling behind. "We are more concerned about the risks of moving too slowly than we are about AI skepticism," Wassmer commented, reflecting a broader industry sentiment about the rapid evolution and adoption of AI technologies. This transparent embrace of AI, despite potential skepticism, positions Epic to leverage the technology for accelerated development and problem-solving.