this is mostly copied from ray tracing gems 2 chapter 7 (Texture Coordinate Gradients Estimation for Ray Cones, by Wessam Bahnassi).
There's a weird bit about radians vs degrees. We'll figure it out later when the book becomes available.
We used to dispatch rays anyway even if there was no models to render and tlas wasn't built (which is the case for the first few frames).
This ended up crashing AMD gpu when using some (but not all) variants of rgen shaders.
With this change we'll check for whether there are any models to render, and if there are none, then we'll just clear frame to black.
This change also refactors ray tracing a bit.
track brush models movement and update lights grid clusters with model transform and stuff
also implement animated textures for rtx
and also increase per-cluster lights limits
This is a massive hack, because we hardcoded some valve/lights.rad file
right into vk_rtx.c, and this is most certainly is not correct data. We
expect maps to have more custom rad file entries.
TODO: consult https://github.com/MaestroFenix/Half-Life-Resized-Maps
Also, emissive surfaces are no importance sampled, so it's noise fest.
this basically checks that acceleration structurs are building without
any vulkan errors (we still don't know whether they are bulding with
correct geometry though).
we also have compute shader pipeline ready for ray tracing (yay)
but it doesn't do any raytracing yet
Ivan 'provod' Avdeev