RTX Remix support

[Xottab-DUTY]

We have few folks working on RTX support on official RTX Remix Showcase Discord: https://discord.gg/VgG6SZFtaX

This issue is created to track progress and discuss any details, plans, what to do, remaining issues, etc.

The way 1:

1. Main issue and a task is to reimplement/restore fixed-function pipeline in the renderer (#1313).
2. We need to reduce culling, e.g. make objects behind the player still render, so that RTX runtime can properly light the game.

The way 2:

1. Just use Remix API instead of any DX9 FFP code.

[CasualDev242]

I'd like to help if you don't mind. Where to start?

[Xottab-DUTY]

@CasualDev242, hi! It's better to join official RTX Remix server from the link above. In the #general channel you'll find a S.T.A.L.K.E.R Trilogy thread, we'll help you with the setup there 😊

[CasualDev242]

Will do!

[EliteCombineSoldier]

We have 2 important issues to focus on:

1st issue:

The sky still uses a shader..in rtx remix surfaces that uses shaders appear as simple colors.. and thats an issue because now rtx remix thinks the skybox is a solid object surrounding the player which blocks sun light.. making the game unplayable

2nd issue:

Some objects are black or non existent (like stalkers and mutants for example) and the terrain is tiled.. this obviously makes the game ugly and/or unplayable

Minor issues:

• Each gun has a different FOV which makes stuff look weird with rtx remix

• The map is big and going to some places causes vertex warping (potentially an rtx remix issue)

• The distortion effect caused by anomalies and gun fire doesn't work and appears as flying bump maps (i think?)

There is more issues but this is what i was able to gather from the top of my head

[yohjimane]

Added some resources below :) The rtx-support branch is now linked, that branch contains WIP ffp changes required for remix to function better, as well as default rtx.conf for remix and a helper bat script to launch the game with correct options. There is also a wiki page for RTX remix setup.

Main branch for rtx support

RTX Remix setup instructions for debugging

[Xottab-DUTY]

Useful: https://github.com/NVIDIAGameWorks/dxvk-remix/blob/main/tests%2Frtx%2Fapps%2FREADME.md