# Adding Subsurface Scattering (SSS)

Subsurface Scattering (SSS) is an effect that allows light to pass through and bounce around inside an object. This effect can be useful to generate a realistic skin material or for making an object feel soft.

![Examples of Subsurface Scattering](https://517145833-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNSnZWGFAkrNOu0viEa54%2Fuploads%2FRH5YYz7SXJhvqjm0AEGH%2F10a.png?alt=media\&token=48dd9325-937f-448e-b4c1-da96e7d14500)

Here's how to set up SSS:

* First, duplicate the Skin material by clicking the `+` icon on the `Material Properties` tab, set it to the main Skin material, make it a single-user copy by clicking the numbered icon on the material data-block menu, and then rename it to something like Skin\_SSS.

![Click on the + icon to add a new material slot](https://517145833-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNSnZWGFAkrNOu0viEa54%2Fuploads%2F2Qcxz4I7r2FxrHk3c5cN%2Fblender_JgTKQYBnU4.png?alt=media\&token=c5c5633d-4c88-4121-a443-8865d02cdabc)

![Set the new material slot with the main Skin material](https://517145833-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNSnZWGFAkrNOu0viEa54%2Fuploads%2Fy5bjpeIgmP2C8D917V0o%2Fblender_m46AuQ8KRd.png?alt=media\&token=8a3ec2c2-8a66-4e78-a8be-f8a70cdf0e25)

![Set it into a single-user copy by clicking the numbered icon on the material data-block menu](https://517145833-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNSnZWGFAkrNOu0viEa54%2Fuploads%2FSmgofutGc2axsmt72C4P%2Fblender_49ZiptfwUl.png?alt=media\&token=04d4577e-bcf1-458d-b53d-742289eccadd)

![Rename the material to something like Skin\_SSS](https://517145833-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNSnZWGFAkrNOu0viEa54%2Fuploads%2FKeDHxeH0yv2XxdtcnyRk%2Fblender_mqEGKPSggC.png?alt=media\&token=30bb4ede-66a4-4a8d-b5dc-aebb546cb2f4)

* Open the `Shader Editor`. In the `Principled BSDF` node under the `Subsurface` section, set the `Subsurface Method` to `Christensen-Burley` if it's not yet set to that. Then set the `Weight` to 1 and adjust the `Scale` depending on how much SSS you want to have (I recommend starting at 0.5).

![Set the Subsurface settings](https://517145833-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNSnZWGFAkrNOu0viEa54%2Fuploads%2Fu8rqgtEaZjKI81PM59T9%2Fblender_3j6c834jqa.png?alt=media\&token=3bd0d41c-5fb3-47bd-a7e2-b65d624c9317)

* Once you do that, select the mesh you want to have SSS, set it to local view with `/`, and go to `Edit Mode`. There, select the faces you want to have SSS and assign it to the new Skin\_SSS material by clicking on the `Assign` button on the `Material Properties` tab.

![Select your mesh, go to edit mode, and select the faces you want to have SSS](https://517145833-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNSnZWGFAkrNOu0viEa54%2Fuploads%2FMoLkMZrmYJaHUXoOqTso%2Fblender_OpXT7GenzI.png?alt=media\&token=e8154443-a985-43a4-b344-d5286e9796a2)

![Assign the SSS material to the selected faces](https://517145833-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNSnZWGFAkrNOu0viEa54%2Fuploads%2FodlahANPPpe47TTqKFAH%2Fblender_t0le5Gx9UM.png?alt=media\&token=fa79fc94-93ee-4a02-8ec9-c154ce1d27ff)
