Huzzah! Turns out it was just an issue with the transformations for the background not applying. Using straight screen-space mapping for this, and spherical mapping for the secondary rays env sampling

With UV debugging: rgbu, v, 0.0f

lost warping in the background, but its still not right.

Checkerboard was incorrectly evaluating the UV coordinates. Fixed that

Fixed spherical projection issue, but the background is totally cooked lol

Got the checkerboards working, but there is still some warping in both the spherical checkerboard and the environment/background

Gotta figure out what the heck is going on there, but background/env is working. Checkerboard isnt

Got fed up with the code rewrite and decided to do it my way. Isolated the teapot and got the UV projection and whatnot done.

Checkerboard isnt loading, fixed some texture mapping I think, and got the env to actually load, but it seems to have the wrong mapping.

well I dont think thats quite right... Texture doesnt seem to be loading in the no intersection rays and the teapot has no texture. Checkerboard isnt loading either