The first ones use a nearest-pixel filter and the second ones use a linear filter.
Now I have tested and stable ray tracing on the C++ side. Time to port to GLSL.
Still using my hacky shadow tracing method at the moment, but notice that I added in a Lambert calculation for lighting and determining if rays need to be cast in the first place (removes roughly half of the required rays.)
I’m going to have to write an article on this, but here are some screenshots to show what I’ve been working on.