I’m trying to find a way to incorporate SSS into a PBR material using Eevee. So far, using 2 Principled shaders mixed at 50% seems to do the trick, however, I feel this method could be improved.
I can’t seem to find a good way to “fake” SSS. When I search for this and related terms on Google, I only turn up results for “SSS for Cycles is here!” Not really helpful.
I’d rather have a fake/approximated SSS shader because mixing that in Eevee would be easier in theory. Shader to RGB doesn’t work for SSS shaders in Eevee right now (and probably never will).
(Some of the answers below were to the previous version of this question, I have since improved it so others may understand what I’m trying to accomplish.)
No. For example, if I use a Principled BSDF node, the normal map applied to it will also affect the Subsurface Scattering. I want the Subsurface Scattering to remain unaffected by the normal map. I don’t see a good method of combining, say, a Diffuse node and an SSS node to create the result I’m looking for.
I wouldn’t recommend Principled+SSS if you have a glossy component as the result will be wrong. Also 2xPrincipled would be wrong as you’d get one glossy with normals and one without. Glossy should always be mixed in last via fresnel. I’d suggest go out there and grab a manual PBR material setup. Principled is for 90%+ of regular stuff, but sometimes you just have to set it up manually or go find something.
As for normal/bump maps affecting/distorting shadows, it can’t be done in Cycles. It will affect shading (obviously), but not shadows. This is a shading trick we used to use back in the day, maybe this is a limitation of path tracing, I don’t know. Curious, would this be possible with a new shader type (not currently available)?
As I add the SSS at a low value, it just looks blurry as it’s taking too much away from the darker values, which is to be expected since it is passing light through.
This wouldn’t be such a problem, but the Shader to RGB node doesn’t work with SSS. I assume this is because it’s being calculated afterward. Another issue is that I also can’t apply the effect on metallic shaders using the Principled BSDF.
i am not sure, what look you want.you can however mask the sss amount at the subsurface input,but keep in mind that the sss has a radius effect.
or you can “hard mask” with a mix shader and a second shader.
and or you can use a colormix RGB for the base color input to mask or mix the colormaps.
in theory you can mask almost everything.
I’m not exactly sure how masking might help me, if you wouldn’t mind explaining further.
The look I’m going for was inspired by shaders I saw in the Spyro: Reignited games. I noticed that many of the objects that made up the environment had a color fade effect similar to what an SSS shader can create.
Here I have an example of something similar to what I want, I’ll try and get screenshots from the game once I get home:
with masking,i mean, if you want only the stones with sss for example,the AO shader could maybe work as fac.
if you want to use sss,then lower the radius first to 0 then increase it in small steps until it covers the stones like you want.and use the random walk sss mode ,its working better for edge like sss.
