Textures having issues with PBR blend modes

[Stupid Doge]

hi, i’m just now getting into PBR on SL. i’m having an issue that my textures only appear correctly if i set the blend mode to blend. if it’s on opaque or mask, the texture looks choppy. 

in blend mode it looks normal

i could settle with blend mode, but unfortunately that means everyone who uses alpha hair will have glitching like this 

 

i don’t want my customers to have to deal with that. i’m not understanding why i can’t have my textures in opaque mode, as there is no opacity. the opacity channel isn’t on in substance painter. 

this is what the layers look like in substance painter for my texture 

i have a smart material, then a solid base color on top. i have a darker color on top to bring out the AO map details and then a lighter curvature layer on top of that to bring out those details. this is how i’ve been baking my legacy textures to bring out the details i want so please feel free to tell me if i’m making a mistake.

 

i would really appreciate any help because i would like to start doing PBR textures without hugely inconveniencing my customers :(

[Frionil Fang]

That is almost certainly a bug if you ask me, though I can't tell which part is bugged: the colorspace is getting converted causing the dark end colors to be crushed up and banded.

I initially thought that was on purpose due to the whole "linear colorspace is used except base color texture is required to be sRGB" in glTF spec, but if it's not happening in alpha blend mode then something is clearly wrong and ideally the opaque mode colors are *not* meant to be crushed; if the blended shader can handle it without banding, I don't see why the opaque one couldn't. Blended PBR behavior also matches classic materials' behavior.

I wrote a bug report about it: https://feedback.secondlife.com/bug-reports/p/base-color-is-interpreted-inconsistently-between-blend-opaque

Edited August 4 by Frionil Fang

[Frionil Fang]

As for how to work around it for now: I'm really not a pro but I believe the base color should have only that, the base color. Details to bring out shading and shape should go on the occlusion and normal maps and left for the scene lighting to handle, those maps don't seem to have banding problems.

[Stupid Doge]

6 minutes ago, Frionil Fang said:

As for how to work around it for now: I'm really not a pro but I believe the base color should have only that, the base color. Details to bring out shading and shape should go on the occlusion and normal maps and left for the scene lighting to handle, those maps don't seem to have banding problems.

thanks a lot for your reply, i’ve searched everywhere for info on this and couldn’t find anything. it’s been driving me crazy all day lol. i understand about the workaround, thank you. i did like the stylized effect i can get when i go in and sort of alter my AO and curvature to my liking so i hope a fix happens soon, but i will look into trying other ways. silly but i actually didn’t check any light colors until i saw your reply and lo and behold…they work perfectly it’s just black 

[Frionil Fang]

5 minutes ago, Stupid Doge said:

silly but i actually didn’t check any light colors until i saw your reply and lo and behold…they work perfectly it’s just black 

Yeah, the color space transformation (which hopefully is not meant to happen in this manner, fingers crossed LL agrees it's a bug and fixes it) loses detail from the dark end and adds it to the light end, the balance of intensity values is different to the usual sRGB.

I ran into the exact same problem trying to make some black marble with lighter veins, it ended up looking very ugly due to collapsing only to 2-3 levels of gray and I compensated by discarding color detail and amping up roughness/occlusion details instead.