Cars Artificially brightening interior

GeekyDeaks · Nov 24, 2021

Hi all,

I'm trying address an issue I have in certain cars in VR which is really, really dark interiors. I actually think this is not a fault, but I'd still like to artificially brighten them anyway. I have played with the general settings e.g. gamma, but this seems to result in washing out the external elements, so I figured I'd see if I could change the values of the internal materials instead. I found that I could increase the ksAmbient in the CM showroom for the desired effect, but unfortunately, whilst this seems to persist in both the CM and AC showrooms, it doesn't appear to affect the materials whilst in-game.

For reference, this is what I am mucking around with:

Am I just being dumb and missing something obvious, or is this simply not the way to go about the task?

GeekyDeaks · Nov 25, 2021

I found a way to do this in the end, but I'm not sure if it's the best approach, so if more knowledgeable folks have a better suggestion I am all ears. Anyway, this is what I did:

open the car in CM Showroom
select an internal material that you want to alter(seems to usually have an INT_ prefix)
open the Textures/txDiffuse settings
reduce the gamma to a crazy low value (2-3%) (EDIT: actually, I found this varies from model to model)
calculate AO and save it into a skin folder (e.g. skins\00_lms_01\INT_Occlusion.dds)

Before:

After:

The screenshots of the mirror don't really do justice to the change in the headset for me. I can see hardly any details in the original as it's far too dark, but I can make everything out nicely now

GeekyDeaks · Nov 26, 2021

After a bit more digging around I found another way to do this that allows a bit more control, but it does require a bit more prep work and doesn't seem to work on all models.

First I loaded the car up into CM Showroom and made a note of all the internal materials and their ksAmbient values. I then created a ext_config.ini in one of the skins directory and put in a bunch of SHADER_REPLACEMENT sections for each group that were of similar values

e.g. for the ks_porsche_919_hybrid_2015 I created the following file:

assettocorsa\content\cars\ks_porsche_919_hybrid_2015\skins\00_lms_19\ext_config.ini

and populated it with this:

[SHADER_REPLACEMENT_...]
MATERIALS = INT_Occ_CARBON
PROP_... = ksAmbient, 1.0

[SHADER_REPLACEMENT_...]
MATERIALS = INT_Occ_RUBBER_Steer, INT_Decals_FLAT, INT_Decals_METAL, INT_Decals_PLASTIC, INT_Occ_PLASTIC_Grey, INT_Decals_Flat_AT
PROP_... = ksAmbient, 0.7

I did also notice some other interesting LIGHTING settings in https://github.com/ac-custom-shaders-patch/acc-extension-config/blob/master/_doc_config_cars.ini, but I could not get them to have any noticeable effect e.g.

[LIGHTING]
INTERIOR_DARKEN_LIGHT=0.1

Anyone know where I can look to see how those settings work?

GeekyDeaks · Nov 27, 2021

More digging... but I think I finally got to the bottom of why my initial changes of ksAmbient did not make any difference in the game. AFAICT, it's down to the experimental PBR shaders not using ksAmbient, but the shaders are not applied to all cars, causing me some confusion as to why it sometimes worked.

Forcing the shader back to the kunos one for the specific material seems to work. e.g.

[SHADER_REPLACEMENT_...]
MATERIALS = INT_Occ_CARBON
SHADER = ksPerPixelMultiMap_NMDetail
PROP_... = ksAmbient, 1.0

I still feel like this a real fudge and there is a better way to do this, but for now this works acceptably for me.