Jaderail - Thanks for your response. The help file in the UberSurface package goes to the Wiki page. It breaks down Refraction and Scale in the SSS settings but omits what group and rate settings. Maybe a breakdown of the translucency and specular 2 also.
Probably my newbie showing through right now. Maybe these are common knowledge things. But if you are trying to figure these things out there is no way to know this. The shader mixer has different names for those SSS settings. At least I think they correspond to the sliders 1 to 1.
One aspect of this recently came up in another thread; Subsurface Group Slider: what does that do? Basically, the Group function allows you to assign different skin surfaces to different groups so that you can handle the subsurface settings for those groups of surfaces differently. You could put the nails in one group, the mouth in another, the head in another, etc.
No idea what the subsurface shading rate does. I know that Interjection defaults to setting Subsurface Shading Rate to 128, and when I’ve looked at the settings for the various elite skins with HSS baked in, they’ve also got shading rates at about that level. When I tried to find information on subsurface shading rate, almost everything I could find said, almost word for word, “This attribute speciﬁes the shading rate used for the subsurface simulation”. Shading rate in general controls quality—the higher the shading rate, the higher the quality, I believe, up to a point, but it also increases render time somewhat. (I hope someone can correct me if I’ve got that wrong.)
Depending on what you’re trying to do, the other thing you need to look at are the Translucency settings, especially the strength. I’ve noticed that for a few characters, especially the fairer ones, translucency strength can easily be set much too high. (A couple of redheaded characters I’ve seen have had translucency and SSS set so high that they glowed under direct light, and UberEnvironment HDR Dawn turned them glowing purple.). Generally, on normal human skin, you don’t want translucency strength set higher than 10%, unless you’re dealing with infants or extraordinarily fair people.
RawArt has a tutorial on using SSS and 3Delight/Studio at DeviantArt. He doesn’t go into much detail about what’s what, just how to get where you need to go. Pay attention also to the discussion underneath the tutorial, especially between Rawn and jamminwolfie. Note also that if you’re working with characters with dark skin tones, where Rawn talks about using pinks and grays, you’ll need to use browns and yellows, respectively—though a rather grayish yellow, if you can swing it.
Hope this is helpful.