id has revealed that, if it hadn't updated its idtech engine to use ray tracing instead of pre-baked global illumination, Doom: The Dark Ages could have taken far longer to develop and been a much larger install size. The company has claimed that just the pre-baked lighting data for all the game's maps/environments could have needed as much as 110GB of storage and taken as much as two months to render fully each time. However, by making this change, the company effectively traded storage and its development time for backwards compatibility and your PC's performance. Doom: The Dark Ages was famously one of the first games to require a GPU with ray tracing processors, with it landing around the same time as other ray-tracing-required titles such as Indiana Jones and the Great Circle (which also uses idtech8) and Black Myth: Wukong. This requirement left many gamers unable to play the game at all, or only able to play with relatively poor performance. Now, in a presentation at the graphics conference, SIGGRAPH, id has revealed its motivation for this decision.