Lets make it clear, its a GZDoom mod reusing some Doom2 assets. Features used https://zdoom.org/wiki/Teleport_Line are impossible in original Doom 1/2 engine. Later Doom source mods received Non Euclidean Geometry support inspired by other engines like Portal System based Build engine (duke3d etc). https://www.dfdoom.com/gzdoom-portal-tutorial/ https://www.youtube.com/watch?v=oUCji83Xt50
Lets make it clear, its a GZDoom mod reusing some Doom2 assets. Features used https://zdoom.org/wiki/Teleport_Line are impossible in original Doom 1/2 engine. Later Doom source mods received Non Euclidean Geometry support inspired by other engines like Portal System based Build engine (duke3d etc). https://www.dfdoom.com/gzdoom-portal-tutorial/ https://www.youtube.com/watch?v=oUCji83Xt50