I've been tasked with writing an assignment on how current games engines have designed their Rendering and Collision systems. Where when I say Rendering system, I mean their rendering pipeline in general. -How is stuff passed to the renderer? -What sort of shader system is used? -What sort of material system is used? And when I say collision system, I mean such ideas as - What space partitioning system is being used to speed up tests? - What is being used for indoor enviroment collisions, BSP ? Whilst I have a good idea of they do it, i have nothing concrete and thus nothing to reference in my writing. There are plently of articles out there for how to implement these sort of things, but Im looking for references that specifically state, "this is how this engine does it, and this is how that engine does it, and this is how our engine does it" etc etc. As I need to source what I talk about. Any help would be appreciated.

This is a highly unusual subject. It is similar to documenting torque values of engine screws by manufacturer.

Articles that discuss such systems may mention trivialities, but those articles get written about *why* the choices were made - the result merely follows from there. Some might also touch on why alternatives were not chosen.

Wiki on Frostbite engine has a link that explains how the engine is designed. There's plenty of similar level material for others as well, just don't have sources handy.

Getting any information beyond that almost certainly simply isn't possible due to NDAs and other legal issues.