I guessed about it. But still hard to achieve real looking.
I think the main problem that in real life we have no surface with 0 thickness, thats why Translucent behave like this in my case.
The best option for me it’s if Translucent shader had some kind of compensation (zero thickness compensation) option for original diffuse.
Because first you setting up Principled/Diffuse shader, and then add Translucent to it, which change your diffuse setup and you need tweak it after.
I don’t think it’s a good solution to add physics-breaking options to shaders. Proper approach is to set up your material with translucency from the start and then adjust light, exposure and textures to get the desired result.
To get this desired result you need every time switching translucency on and off to see real diffuse which is time consuming operation…
All that thin-film does is to match the IOR on both sides of an interface (implying both sides are outside) - It does nothing if you aren’t even using fresnel.
That is a correct workflow. Albedo should be probably just boosted up to compensate the ‘look’ .
Btw @APEC what is going into the Fac of the mix shader node?? That is not my setup. That should just be a (usually low) value, driving how much translucent shader to add (in order to limit the energy conservation breakage, but still feel the effect)
Btw, the original poster’s setup was a tad over-complicated. All you need to do to do this properly is this
Still about four more nodes than ought to be necessary, but it’s not quite so bad.
A full setup would require more though. Ideally you want to use:
So a full node tree might look something like this (I don’t have the necessary maps to make it work, so I’m only showing the node setup. I may have flipped an input here or there, can’t test):
The Mix node going into the Fresnel Normal is there to emulate the effect roughness has on the fresnel gradient. If a material is very rough, effectively you are facing more of it heads on. So instead of the normal direction, in those situations you need the incoming direction.
Finally, I’m not sure if my logic with the albedo map is correct here. I think that’s right, but you might need to actually put the opposite color into the Translucent BSDF. Like, use another Mix node like ALBEDO but invert the inputs and plug that into Translucent instead.
On short notice I found no reasonably quality texture that has both the front and the back side on it for me to try it out.
@APEC can you share your full node setup how you acheived this? Did you manage to solve the borders issue? It seems like an alpha problem
