To get a better performance with the Rift with constant 90 FPS, I've played AC with disabled PP effects until now. But with PP effects disabled, you almost can't see the brake lights and rear lights of many cars and have no sun effects. So I've enabled the PP effects, but with the original PP-filters of AC the game is much too bright and I don't like the auto exposure.
My aim was, that the game graphics should look like before with disabled PP effects, but with working effects for the car lights and the sun. And so I did my own PP-filter.
The filter is for the AC default weathers. I didn't test it with weather mods.
To install the PP-filter just copy the folder "system" to "steam/steamapps/assettocorsa".
(in the folder "backup" is the original "default.ini", if you don't like my filter)
In Rift mode AC always uses the "default.ini" PP-filter. It has no effect, when you choose another filter in the AC menu.
If you activate the PP effects with the rift, you'll loose a lot of performance, and maybe you can't play the game with constant 90 FPS anymore. But for me 45 FPS with ASW (Asynchronous Spacewarp) does the job very well. On my PC with Intel i7 4790K and Nvidia GTX 1070, I've set "PIXEL_PER_DISPLAY=1.6"
in "oculus.ini" and all graphics and PP effects to maximum (only the reflections are set to low and the mirrors are set to medium) and I can play with grids of 24 cars with no issues.
To check the framerate ingame, you can use the "OculusDebugTool", that is part of the "Oculus SDK for Windows" you can download at
PP-filter for Oculus Rift CV1 1.2
PP-filter for Oculus Rift CV1