I cannot active translucency, thin obsorption and volumetrics like in Legacy mat

[Suppybird]

My question is : why do you must make things complicated and difficult and annoying?
Thanks!

[mmarcotic]

Hello,

we do not want users to use the material incorrectly, that's the short answer.

For Translucency, enable Thin Shell (no inside) in General Tab
For Thin Absorption, enable Thin shell + refraction
For Volumetrics, enable either refraction or opacity.

In other cases, these tabs do not make much sense, so that is why they are disabled.

Thanks,
Jan

[Nejc Kilar]

I'd just like to say that Jan summed it up perfectly with this sentence "we do not want users to use the material incorrectly". It's not so much "taking away options from you" as it is "ensuring your materials make sense".

You'll notice similar behavior when you'll try to create a Metal material that has Volumetrics. Metals don't exhibit these kinds of properties so the Physical MTL will grey out that option for you because enabling would be incorrect / not physically realistic.

Edit:
And if we are being even more specific, Translucency itself is basically SSS with the main difference being that Translucency is designed to be used with "thin" meshes. For SSS to work you obviously need thickness and there are so many cases where having actual thickness on the model would be impractical (think high quality tree leafs, if you add thickness you're like 2x-ing the poly count that can already be super high to begin with) so that's where Translucency will take that "thin" mesh and simulate the SSS effect like the mesh has some thickness to it. Obviously, for objects with "noticeable" thickness you'll probably want to use SSS or Volumetric Scattering but for things like leafs or pieces of paper... Translucency!

And so now that we know that I think understanding the behavior where you can't use Translucency if you don't have "Thin shell" enabled makes more sense. Why would you want to enable Translucency for objects that have thickness? That would be incorrect usage of the functionality - Hence, it is greyed out when you aren't dealing with a thin mesh.

Hope that helps!