Fast and Easy SSS Fake in Maya
Software: Autodesk Maya
Author: Dany Bittel
This is an easy and fast SSS fake, that I find quite handy. Even though there are different non fake SSS solutions by now, I still use this technique a lot.
Quick set up tutorial
First, define color / bumpiness / specular shading etc for your shader while leaving incandescence at black. This is how the shader for my beak looks like.
Now we are going to add a second texture that will brighten the dark side of the material. This is where the SSS takes effect.
Create a file texture and connect it to your incandescence slot of your shader. Now this brightens up the shader evenly, this is not what we're going for, we just want to bright up the dark side.
To do that, we need a "surfaceLuminance" node. This nodes outValue gives you the amount of light that hits the surface, normally in a number between 0 (no light) and 1 (full light). We need this value reversed, because we want to brighten those parts that get no light. Create a reverse Node and connect the surfaceLuminance.outValue to reverse.inputX, reverse.inputY and reverse.inputZ.
Now you can connect the reverse.output to the colorGain slot of the texture you created earlier.
A word to the SSS fake texture: Normally where the object is thicker, you'd have less light travelling through the surface, which results in a darker area. You'll have to fake this in the texture file, darken the areas, where you think less light will travel (such as the middle of my beak) and leave those areas brighter where there'll be a bigger SSS effect (such as the borders of my beak).
Imagine holding your object against a bright light. This is the map you'll have to draw, for a good effect. Here you see the color & the SSS fake texture of my beak side by side.
This is the final beak.
(There's only one light in the scene)
- easy and fast to set up and control
- almost no additional rendertimes
- works in standart Maya & Mental Ray
- no plugins / no raytracing
- good for clay / waxy like surfaces
- you can use it on non uniform geometry
- effect is heavely dependent on good textures (or color)
- only good for certain types of effects (not for realistic skin or transparent objects)
- it's a fake, (stylisation)
- needs adjustment for different lighting situations
a good explanation on the Sub-Surface Scattering effect.