Tip: check this out as a general tutorial for adding effect masks to your skin!
~~~ * ~~~
Short and Short Crest hair are two cool short hair style for Victoria 4, Yly, Michael 4, MyMichelle and Genesis and are available in our store: http://www.runtimedna.com/ShortandShortCrestHair.html
The Short and Short Crest Hair files, do NOT include a cap, we made this choice for a series of reasons (a 2D cap blends bad with 3D hair, a semi-transparent cap would multiply rendering times).
Most of the time you won't even notice the lack of a cap, especially if you're using a skinshader with AO (Ambient Occlusion), however this heavily depends on your skinshader AND the light setup you are using.
If the light "kills" the shadows under the hair or is very "flat", you may notice the skin under the hair keeps the very same color of the rest of the face, and doesn't apparently show any shadowing. This won't appear very realistic as the skin under short hair should be either lighter (because it's not as "tanned" as the rest of the head skin yet) or darker because of the hair shadow.
To make things look more realistic, we have decided to provide some mask you can add to your skin shader. You can download the masks here: AlfaseeD's Short Hair masks (just install as you'd normally do with any Poser / DAZ Studio product)
You can use them on any skin, of any color and you can decide whether you need / want the skin under the hair to be lighter or darker than the rest of the face.
Creating the needed nodes
1- First of all enter the material room and create a Color_Math node (right click -> New Node -> Math -> Color_Math) and set it to Subtract, then create an Image_Map (right click -> New Node -> 2D Texture -> Image_Map) and plug it to the second value
Load the texture for your model
2-Then load the texture map you need for your model: masks for Victoria 4, Yly, Michael 4 and Michelle are provided. So depending on the model you're using you have to load the matching map. Note that you have to apply the additional nodes to both the skinface and the skinhead materials (head and neck parts depending on the model).
As for the maps, they will install in Runtime --> Textures --> Alfaseed --> shorthair --> BodyMasks
Final nodes setup
3- Now, this is the "tricky" part as every skin shader is different.
What we need to do is to plug the diffuse texture node or series of nodes into the Value 1 of the Color_Math node. In our case (this is Alice' P9+ SSS material) we are using the Alternate_diffuse channel (other skin shader setups would use the Diffuse_Color channel).
Tip: You can easily figure out which one your skin shader is using, it's just the one (Diffuse_Color or Alternate_Diffuse) set to 1!
So, the node that plugs into the Diffuse_channel (Color_Math 2 in the example) will have to be plugged into the Value 1 of our newly created Color_Math AND the Color_Math will be plugged, in its stead, in the Alternate_Diffuse channel (easier shown than written).
As you can see in the last image, you can easily see how the masked part is much darker now. You won't need it to be that dark, that value was set to just show it clearly.
4- You can chose any white to black value for your mask, depending on what you need / like. Below, just an example with a fairly dark gray (the lighter you go, the stronger the "shadow" will be.
3- If you want a lighter skin under the hair, all you have to do is set the Color_Math Math_Argument to add instead of Subtract: and you're done! (Just remember to do it on both the face and skin materials!)