How to get translucency in parts of skin material?

Question

Alright, Ive watched more complex skin material tutorials for 2.8 but want to know the simplest way to go about this given my skin setup - Ive painted the base material and normals for my skin material in Substance painter and apply them to my model by feeding them into the respective slots in a Principled BDSF.

What I need now is translucency in certain parts of the mesh where human skin is normally translucent, like the ears (here is a successful example):

This requires some sort of painting to delineate where light should shine through and where it shouldn't - so far in my material setup Ive tried a mix shader between the principled BDSF and a Translucent node, as well as checking the 'Subsurface Translucency' box.

I just need to know what kind of map/how I might paint a translucency map and how I can plug it into my material setup to achieve this selective skin translucency?

Answer 1

To achieve the effect you are going for, there are 2 ways to do this, depending on what rendering engine you are using. I will show you both ways to do it.

Using cycles: to get translucency in certain parts of your mesh, all you simply need to do, is turn up your subsurface value in the shader editor. (see picture below) after this, the light will shine through only in parts the mesh that are thin enough. to adjust how much light you want shining through based on how thick/thin your mesh is, you can edit the "subsurface radius" values directly underneath the "subsurface" value on the "principled BSDF" node. (see image below) After that, it's pretty much done. You can adjust the other settings to your liking.

Using Eevee: When using EV to achieve this result. you do pretty much all the same things that you would do as if you were using cycles (read the above text first if you haven't already) except for one thing. Make sure you have the desired object selected, then go to the materials tab, and enable: "subsurface translucency". (see image below) Once this is done, it should work. adjust other settings as needed.

And there you have it. I hope this helped! :)