An Updated Subsurface, and a Transition!

As I moved further into working on "Kyon", prepping for GDC brought more pressure to raise the bar on every asset. With this in mind I set about trying to figure out a more visually appealing subsurface material that would be somewhat heavier but look amazing for our big boss characters. For this process I used a bust version of our human base model as a basis for this project. One of our bosses is a Basilisk named Biggie. Since he paralyzes people we also needed to include a transition across the surface of the object so while this demo will focus on Subsurface aspects there is also a tied on transition happening as well.

Starting off let's take a look at our states. We have a Petrified stone state, and a human flesh tone state.

Pretty simple setup. The hard part is getting the subsurface to look at this level of quality,

We start by setting up the basic falloff setup for our diffuse texture. This fresnel will allow us to change what would be called a heat map of our character, letting us as the artist change the color hue of our character on a whim without messing with our texture map. This method gives us a nondestructive way of manipulating our colors and object looks without adding new texture samples.

This is mostly simple house keeping and quality of life methods. Generally the more detail in characters the better. It's very hard to ruin a character with well crafted details, especially when they are parameters that can change on the fly. As you can see we have quite a few micro detail textures that flow into roughness, specularity, and the normal map. This allows us to have a really nice shine spot on our character that helps define otherwise hard to pick out pore details.

This is where things start to get complicated. Essential what we are doing here is creating a material function that provides parameters for two fresnels that are blended over each other to create a sense of depth. After that we can add our three colors and since they are parameters we can change them as appropriate.

The next part is less stressful, as here we are mostly just plugging in parameters that we already know the general location for. The only thing to note is that the texture sample is a tileable veins texture that can look something like this.

This adds a subtle change in our characters flesh tone that adds quite a nice touch on closeups.

It's incredibly subtle, However with parameters the strength can be changed. This will be helpful for characters who need to look unhealthy, malnourished, crazed, etc.

This is the full material, the subsurface plugs into the subsurface color, and you have your new character! The next part is the transition.

First we set up our construction script to match our parameters from the material we made. Now that we have called them in the construction script we can edit them in our blueprint which is how we will be setting up our transition.

It's a fairly simple setup, but we take our scalar parameter labeled there, and multiply it with a grayscale map, After that we lerp our two states together, like so:

Now comes the blueprinting. We take our scalar parameter, and we hook it up to a timeline. This allows us to transition between -1 and 1 smoothly giving the dynamic effect that we get in this video!