Subsurface scattering is a phenomenon where light penetrates an object’s surface, scatters beneath it, and exits at a different point, creating a soft glow. This effect is commonly seen in materials like human skin, leaves, or certain plastics.
In X-Ray you can achieve this effect through Arnold’s Standard Surface and Arnold’s Hair Shader.
Standard Surface Shader
X-Ray won’t bake any SSS map unless you have SSS or Transmission Enabled in your Standard Surface shader, to do all you need to do is to make sure “Weight” is above 0 for either Transmission or Substance.
Now, if you bake, your mesh SSS will also get computed.
Updating Shader:
After you bake your mesh once you can change the weight in real-time and control the amount of SSS or Transmission effect, but if you set the weight to 0 and update the shader (either manually or by baking light or reflections) the baked SSS map will get removed from your real-time shader and increasing the weight won’t give you any SSS effect, in this case you don’t need to re-bake your maps, just increase the weight to be above 0 and update the shader again (you can do that by using update shader hotkey or by using “Update Shader” button in X-Ray window, the same map will get assigned to your real-time shader, and again you will have SSS effect, and you can modify the weight and see its effect in real-time.
SSS Buttons:
Build SSS: Select an object and press this button to build an SSS map for that object
Set as SSS Light: Select a Light and press this button to mark that light as SSS light, SSS lights will only affect the SSS of your mesh and won’t be enabled in light baking.
Assign SSS: if you already have SSS baked, but you removed the SSS maps from your Maya scene, and you want to re-assign the SSS map to your object, you can select your mesh and press this button, and it will re-assign the maps to your real-time shader.
Tips:
SSS won’t work on Metallic Surfaces
if SSS map is noisy, turn on denoiser in Arnold render settings.
