I'll write a series of "n00b tries to pathtracer" blog posts. Mostly for laughs, and also to have something embarrassing in the future :) http://aras-p.info/blog/2018/03/28/Daily-Pathtracer-Part-0-Intro/
Great initiative - you mention C++ and C# - but have you considered doing it in C11 ?
@aras @jakob C99 support in VStudio is okay-ish (no dynamic arrays, but designated init and 'static inline' is in), e.g. stuff like this compiles in VS (but only in C-mode, not as C++): https://github.com/floooh/sokol-samples/blob/master/d3d11/offscreen-d3d11.c#L177