The past two days I spent experimenting making a skin shader. It seems to me that skin has two kinds of reflections:
Refl 1: On the top surface. Color:white. A bit sharper than
the other reflection. Some areas of the skin are glossier, for example the nose, or there where skin is stretched. Also I think it is shinnier there where there are no grooves; so on top. So here I used a roughness of 0.105, and plugged a map. The map is a desauterated skin picture. It has PRB fresnel from Cynicat pro.
Refl 2: I think there is another glossy layer, but more rough. Maybe it looks a tiny tiny bit metallic. So in the color input I put the skin albedo picture and put the roughness to 0.24. It has PBR fresnel from Cynicat pro.
And I use the Glossyfix node. ( fixes a problem with rough glossy).
I use to subsurfscattering nodes.
1: Scale: 0.15, Radius light pink, texture blur halfway.
2: Scale: 0.3 , Radius Darker pink, full texture blur.
Second one is mix in for 25%.
Using a normal map for the grooves and pories in the skin, Same scale as the top reflection layer.
Problems:
A) When I look straight to the skin,( not from a grazing angle) I don’t see a subsurfscattering. It almost looks like plastic. While, when I look at skin pictures on the internet, then look softer. I cannot bump up the subsurfscattering, as you see in one of the attachments; the whole hand is scattering.
B) When I look at my own hand, I looks as if the skin is translucant. But when we use the translucancy shader, it makes things look thin and hollow; It is for thin objects like leaves and paper.
So I cannot get the effect I am looking for.
I hope to see a few suggestions,
Some background notes i have when i use sss:
Cycles is a kind of PBR out of the box, so my model size matter, my lights and environment are really important for a scene. Everything will affect everything. I usual set everything and according to the shot and i fix what have to be fixed if sss if too strong then a reduce it, or i RBGmix it with some diffuse. Sometimes i RBGmix map (kind of red) on the radius socket to have even more control.
Usually sss will eat your bump better put strong one to have enough bump effect.
Yes you should sss.
Edit: I just noticed that your node setting is a bit different from what i have been working on, I usual add 3 or more SSS together and on top i can mix diffuse.
@Database: I think very rough glossy as you have is a good idea, but since I want to follow the rules of energy conservation I wouldn’t use the add node. So I will experiment with very rough glossy ( and on top of it a sharper glossy).
I see in your node setup a noise texture multiplied with fresnel… I will experiment with that as well.
@ErickBlender;
-My model has a size as in the real world, and I use an HDRI environment map. I learned that without colormanagement blender gives mostly a bit flat colors. I try not to, but often I use colormanagement to bring a bit more contrast and color in the render.
-Indeed, I noticed that in one setup the skin looks ok, and when changing the light or camera, I have to correct SSS and some other nodes. I hope to reduce this, and come up with a shader that suits most setups.
Ah, SSS eats bump. That is a good one.
@general
For three days I am tweaking fulltime now, and still I cannot find what I am looking for, but I think I learned quite some things.
If we really want to render good skin, I think we need more geometrie; the bones, and the deeper skin layer. The SSS is not visible at thicker body parts. Well you can bump up the SSS scale, but we don’t look like that; Light is not scattering through our body.
A skin shader doesn’t magically turn your model into a realistic one. If the diffuse or albedo map is not realistic, the Skin Shader is not going to fix it. A skin shader is just a tiny part of getting skin rendered realistically; realistic albedo map, high resolution model and then make a normal map of it, etc.
-But anyway I am doing my best to get a very good skin shader and have some updates. Some are maybe rediculous; I mixed in a tiny bit of velvet shader ( Grazy?), yes, I thought because the dead skin and the hairs on the skin gives it a velvety effect? And I mixed in a tiny tiny bit of a translucent shader ( also grazy?), this because at thicker parts of the body SSS doesn’t do anything (?) and to get at least a little bit an effect that the skin is not pure diffuse, I used a translucent shader.
