Genesis 8.1

[Alessandro Padovani]

This is just a head up. Didn’t dig in myself but I’m curious what others may think or wish for the new upgrade. It seems there’s a new facial rig that’s FACS compatible, and a new pbr skin shader that I’m wishing to support.

https://www.daz3d.com/genesis-8-1

[Marti]

Yes i would love to see this, at the moment im trying to figure out how to mirror Victoria 8.1 setup in Blender but i have trouble with importing morphs. Maybe Genesis 8.1 is not supported if it has different facial rig?

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[Thomas Larsson]

I downloaded DS 4.15 yesterday. Most things seem to work with G8.1F that worked with G8F. I had to add Body to the list of skin materials, and udim support is broken, because the arms and leg textures are named incorrectly. For arms and legs they use the G8F textures whose names end with 1003 and 1004, rather than 1004 and 1005.

[Alessandro Padovani]

Thomas, didn’t download anything yet. But from what I read in the product page, G8.1 gets a different uv layout thus textures set. We should be able to get it with “load uv set”, if for some reason the new uv set is not the default.

[Marti]

Yess it’s because they separated the head part from torso, so there is an extra UV island

[Alessandro Padovani]

Here’s a very first test. To get 8.1 we have to download daz studio 4.15 + the new 4.15 default resources + the updated G8 package.

Now it seems there’s not a G8M 8.1 and we only get a G8F 8.1. When we load her we get a new “base 8.1 female” uv map and the new textures, but the new skin shader is not used. We have to apply the skin shader by hand, shaders preset > iray > daz pbrskin. Unfortunately it also seems that the new skin shader doesn’t convert automatically from uber. So we at least have to enable translucency to get a first reasonable version of the new G8F 8.1 with the skin shader.

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Below the comparison, on the left G8F 8.1 with the skin shader applied to the face material, and on the right G8F.

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[Alessandro Padovani]

Now a first import test.

To me it is incredible that the plugin doesn’t break with the new shader. It means Thomas did a very good job on the code. It is also incredible that the new imported shader is not a total mess. Below we get the bsdf option and the 8.1 face is quite fine without any fix.

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Then if we look at the material the translucency is imported. But also there’s a volume that I have no idea where it may come from, with only absorption and no scatter. So a very first fix can be to delete the volume node for the new skin shader, since it seems not volume based as uber was.

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edit. Indeed there’s a volume section in the skin shader, so there’s where the volume comes from. But in our example it is disabled so the volume node should not be generated.

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[Alessandro Padovani]

Below a backlight test that better shows the improvement. First iray, then the default 8.1, then 8.1 with the fix. Since the new skin shader is not volume based it gets the translucency to be more visible. That is, there’s no volume absorption. Here I fixed the face, head and ear materials. Test scene included.

Of course this doesn’t mean the new skin shader works yet. There are plenty of parameters there. But this is a first improvement for translucency that seems quite useful.

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[Alessandro Padovani]

Here another example where I turned off the hdri, so to show better the backlight effect. First iray then blender with the fix. They match quite fine. To me it is a bit odd that the new skin shader works fine with translucency alone, I’d expect some sort of sss to be involved. But as a first step this is not bad.

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[Alessandro Padovani]

Then below there’s the principled conversion. Again I’m quite surprised that it works fine enough with no fixes. As for principled it is sss based though, so it can’t do translucency and the backlight test fails.

I’d stop here for now. We got a first look at the new skin shader.

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[Marti]

I'm curious as to why the shading has to match with what daz3d do? I think It can be done a lot better and simpler. Maybe it's to support Eevee?

[Alessandro Padovani]

Because this is what material conversion is for. Then “better” is often subjective and everyone could do his own “better” version.

That said, it is possible to have alternatives to material conversion of course. For example the daz bridge provides a easy custom shader that the user has to fix. That is very similar to a principled conversion in my opinion, plus the conversion has the advantage that you start with shading that’s similar to the original.

I do agree that the bsdf conversion is not easy to edit. It requires some deep knowledge of the blender nodes. For people who wants to customize the shaders in a “easy” and “better” way the principled option is much more friendly. That’s actually “principled” for solid + “none” for refractive that provides the easiest setup to start from.

For the record I do not agree on the “none” name since it is misleading for the user. It doesn’t mean there’s no refraction, but that refraction is handled by a single principled node, thus at the cost of conversion accuracy, but easy to edit. The materials popups explain it fairly well though.

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[Marti]

Yess for sure, im sorry if my question came off a bit arrogant, i didn’t meant it that way.

Yes that makes sense and i didn’t knew about the material conversion

Yes to mirror daz3d Iray skin shading in cycles seems like a lot of work. But yes having similar shading setup as in Iray, I can see it benefiting daz3d users for sure.

Maybe Refraction should just be “Principled” if it’s using the build-in refraction?

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[Alessandro Padovani]

it didn't sound arrogant to me, just a bit naive, so I thought some explanation could be useful to others too

[engetudouiti]

Alessandro, so what you test is only show how iray translucency shader work with sue PBR SKIN new shader ?

Though I do not know if newest MDL version offer new SSS shader,

but after all PBR skin shader should be written by MDL only, then at least as my old knowledge

MDL always use Volume shader to get SSS effect. (volume absorption, and volume scattering = mainly for SSS)

then for Skin, iray dev expect use Diffusive translucency shader as filter to which RGB will be circulated for Volume absorption .

if you use translucency shader with iray uber without SSS and Volume setting, I suppose that means you only show diffusicve translucency shader effect.

(blender SSS shader offer diffusive translucency and scatter at same time.. then about scatter we can controll more with RGB scale (how each color component will scatter when they hit 2nd = sub surface with distance (1unit = 1m as default) )

So at current with your setting, as usually blender cycles SSS shader offer more real SSS effect, because in iray you only use diffusive translucency..

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[Alessandro Padovani]

Yep translucency alone is not good for skin, but it is an example of the pbrskin conversion. I’m working on it and I’ll publish a first version soon.

[Alessandro Padovani]

A first implementation of the pbrskin for cycles is now available, see #349. So I'm closing this one.