: Avoiding slow floating-point calculations, which was critical for the CPUs of that era.
: Using BSP trees to split a 2D map into sub-sectors, allowing the engine to determine which walls to draw first without sorting every frame. DOOM.part08.rar
The most famous "interesting paper" related to this topic is: If you are looking for a deep dive
: Optimizing how floors and ceilings were rendered to save processing power. : Avoiding slow floating-point calculations
If you are looking for a deep dive into the code and architecture, the provides a comprehensive breakdown of the engine's internal logic, while Fabien Sanglard's Game Engine Black Book: DOOM is widely considered the ultimate "paper" or book on how the technical magic of DOOM was achieved.
However, given the context of DOOM and "interesting papers," you are likely looking for the landmark research on the and its revolutionary use of Binary Space Partitioning (BSP) .