[WiP] Community shader PBR support

[Exist]

Hi, writing about support for the new Community Shaders PBR assets. Hopefully not much would be needed from your side. I will mention some facts I believe are causing issues with LODs. Because the PBR textures are incompatible with vanilla, we use unique paths (textures/pbr/ prefix) to avoid unintended meshes from using one of them and looking wrong. Meshes that use PBR can be distinguished by the Unused01 property in Shader Flags 2. PBR albedo is brighter than vanilla diffuse and is saved in dds with the sRGB flag, which converts it to linear on the gpu. Now the problems:

1. Some object LODs seem to be using regular textures, for example mountains. Because LODs won't use the PBR shader, using unmodified PBR textures makes it look wrong. This is our issue and I think authors can just generate lower res textures in the vanilla paths that will only be used for these LODs. I don't know how many LODs actually use regular textures but hope not many.
2. TexGen seems to ignore PBR textures. I suppose TexGen always uses vanilla paths and ignores Texture Set records, otherwise I don't know why this would happen. In this case it would be nice to take texture set paths into account, or check if a PBR path exists before vanilla one. For landscapes we could also have authors generate low res versions at vanilla paths, but it's not viable to do this for everything.
3. DynDOLOD uses PBR textures, but probably because of the sRGB flag (which converts them to linear) the LODs are too dark. This happens to tree LODs, objects such as farmhouses and nordic ruins seem good, but not sure. This would probably happen in the textures in the previous point too if they weren't ignored. From our experiments vanilla diffuse is roughly halfway between usual PBR albedo brightness in linear and sRGB. So it would be best to do something like apply power of 1/1.5 to make the brightness consistent with vanilla. Ideally it could be multiplied with ambient occlusion and adjusted based on metalness which are in another texture, but that's not needed.

Hopefully I got the reasons for why it doesn't work right, I will include some comparison screenshots and links to PBR assets so you can try it yourself. Thank you for taking the time to read this and I hope this can be supported. Oh and feel free to ping me or others on CS or Cathedral discord, I might forget to check back here for some time.

https://imgsli.com/Mjg5ODQ5
https://imgsli.com/Mjg5ODUy
https://imgsli.com/Mjg5ODU0
https://imgsli.com/Mjg5ODU1

More info about our PBR implementation: https://github.com/doodlum/skyrim-community-shaders/wiki/True-PBR

Some assets to try:

Trees - https://mega.nz/file/dqdzGLwY#jBJFwPIWv7iX314UEKZnHCRvlITLbXI7saLY-4oV6Nw

Farmhouses - https://mega.nz/file/duUxDKiA#mnzDzjBFXEIDq-MFoucOHRJT55wOmbUNHOLZ5JxG3lY

Lots of other stuff - https://onedrive.live.com/?authkey=!AB5oYH6iqIMDkHM&id=C23FB01B59FA671C!2427&cid=C23FB01B59FA671C

[Bottle]

Hi Sheson,

I've been messing with PBR terrain lods using xLodgen and have been having kind of off results. Landscape sometimes seems very saturated/bright and very tiled. Using the latest build of xLODGen 128.

Here are screen shots of what I'm talking about https://imgur.com/a/C3CCY7i

I've tried with multiple PBR landscapes, the one in the screenshots is Cathedral landscapes PBR. All seem to have the tiling/brightness issue that I've never had with regular landscape textures.

Here is my LODgen log, seemed to run without error besides the off colored output. Generated with default brightness/contrast and gamma settings.

Would it make sense for me to try 2.2 gamma since the PBR textures are sRGB? I saw that xlodgen converts them to linear and was wondering if that had something to do with it. Again I'm sorry if I'm lacking on providing enough info for you. If I am missing anything let me know. Thanks for taking the time on this.

 

Dyndolod seems to work fine though from what I can tell. A bit more flickering during transition than normal but I don't have any video of that right now.

SSELODGen_log.txt