Gamma correction input socket may need for custom translucency group node

[engetudouiti]

I think gamma correction for SSS color may need to convert daz iray mat correctly .

But it actually make things more complex when user adjust SSS color (basically multipled wiith SSS texture or without texture but set color) in blender. with non volume shader option. = user tweak translucency node property with each experience.

I do not care to customize proeprty, but problem is the gamma correction is inside of the group node.

With usuall workflow I do not hope to open the group node, but only change node group propertys.

At current, you hide the gamma correction only about SSS color (at least about this group node), so it difficult to return non convert gamma. As default or any option, Keep the 2.5 is no problem. I just hope to adjust (basically remove) when it need. (it may only useful when we use color which we set up in daz studio iray shader then import and auto convert, described value.

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[engetudouiti]

Then I requested non volume option for SSS, at same time I said ideally if I use add on offer Custom nodes for any transmissive material, by double SSS + translucency shader.

Then if I use SSS, (non volume) for skin, it offer many realistic variation for detail too.

Actually I suppose daz plan to use Transmitted volume with Scatter volume to get 3 layer skin for Chormatic option. I suppose.

Though daz may use absorbed volume as 3rd (most deep skin color) and how circulate RGB different. (it circulate absorbed and reminder color of the distance user pick up)

But with use 2 SSS we can make almost same effect more precisely. (do not think how convert but work in blender with check color and change 2 SSS props correctly , then get ideal skin for user with use imported textures.

This pic show, 2 SSS shader how work. with 2nd SSS fac = 0 means it only use single SSS node.

then it show s like this.

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with 2nd sss factor = 1.00 means, it only use 2nd SSS , I set up SSS global scale as triple of 1st SSS to represent more deep skin but just keep same RGB scale (I may tweak it too, but make things simple I adjust SSS global scale and each SSS color only for this skin then keep RGB scale for 2SSS.

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Finally these 2 SSS layer (shallow 1st SSS and deep 2nd SSS) simply mixing by mix factor.

After confrim the effect, I add already set translucency color (just favor) effect. (0.3 translucency used) of course you can avoid to use translucency shader at all . by set factor as 1.00

then it will mix diffuse color with Custom node mix factor. (usually I keep it as 0.5, but to set up it I set 0.7 to get more strong SSS effect)

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So I almost confirm any skin which made with iray , can be reproduced by mix 2 SSS (and to easy adjust with translucency = which you do not need to think scale or RGB radius)

I can use this custom node for any translusive material. (then as future request, when Thomas try to improve custom node,

The translucency group node should be key shader, which effect character skin much, so I recommend to use 2 SSS.

at same time, we should not remove translucency. because it is still useful for many matetrial and easy tweak. Though I already content with current simgle SSS with translucency shader, it is kind op basic tips. and it show why I recommend 2nd SSS for custom node.

[Thomas Larsson]

It would be easy to expose the gamma value, but I’m not sure that it is needed at all. The SSS node was originally only used for eevee, and was added in analogy with the gamma node in the principled workflow. But the BSDF setup with volume didn’t work well with eevee anyway, so I guess we can just remove the gamma. If needed it could be added outside the node group, since the translucency and SSS colors are now different.

Adding a second and perhaps a third SSS node is an interesting idea, but I’m not sure that I want to add them just for the purpose of tweaking. To be really useful they should be used to mimic the iray shader, at least for cycles. In DS we have three colors (translucency, SSS, transmitted). What would be really great is if we could find a map to three SSS colors in Blender.

[Thomas Larsson]

OTOH, I found that it was harder to make Victoria look good without the gamma, so I kept it and now it is an input socket.

[engetudouiti]

Yes I hesitate to ask you about this so soon. but I understand some user think, 1 SSS and 1 translucency can not represent, daz volume absorb + scatter with different RGB value. (and it is fact) as true meaning.

And for daz, it count translucency shader as real volume color filter. (or refraction color) on the other hand blender SSS actually include translucency in self. (but it auto adjusted by RBG scale = not real diffuse translucency)

Then even though we use SSS and translucency map in blender, it still diffiulct to show perfect same skin.

Daz translucency >> Volume scatter and Volume apsorption (not mix factor)

Blender trasnsucency (shader) simply mix with SSS (1st)

at current as easy to use, just mix translucency (gloval diffusive translucent color) with SSS workflow, but use 2 SSS should offer more flexibility. Then if you will think difficult for some skin to convert or get the effect, plan it anytime you think it may useful to customise easy.

(as private usage, you already offer what I hoped, so I only need to modify and save it as custom version) . I show use 2 sss is effective way for most of skin. (and it is old technic, for any blender SSS skin without volume shader)

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[engetudouiti]

thanks about gamma, as my side, I do not care, it added or not. just hope to keep outside.

And if vicotria 8 is really difficult, to adjust by translucency with SSS, I may recommend, just for your test, try 2 SSS with clear intention. (think deep skin and narrow skin with 2 SSS by different base color)

The gamma can set as in put is main issue, thanks you solve it. (and it is improtant to set SSS color with blender, I actually did not notice it why my custom version show difference, it is because the gamma changed in the group node. (I do not use auto convert color)