Wii graphics architecture info

[pyromuffin]

Hi there,
I'm currently in the process of hacking the new nvx raytracing extensions into the vulkan backend, and I'm looking for info on the wii hardware, specifically the graphics architecture.
Googling for this info doesn't get me very far, so I am wondering where I can find details on how the hardware works, and how you guys emulate it. I mean, I can look at the code all day, but it would be better to know the rationale.

Thanks!