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These were with attached settings - they seem okay until you realise they are rendering quite translucent, with background showing through...
Let's First Establish this though, so the difference can be mae what is actually scattering and what isn't.
Below i'll show What happens with my character on a few different SSS Angles, and also to establish what SSS Off is.
I tend to have this very slightly as well, but you have to let it render for awhile like in the last example, which is looking very nice.
The phenomenon seems to be a result of high forward scattering. When setting with anisotropy to 0.85+ and rendering with dome or background on (like in attached examples), it looks fine, but when rendering to transparent PNG with no background the way it renders out transparency is a bit concerning.
Edit: Also happens at lower values of Anisotropy (0.5), just less noticeable.
That would be pretty much a Daz Issue then, since it does not happen in any other piece of software.
However, now i can't look past it that your character is looking very photorealistic, the mapping was already good, but now you also have about correct SSS settings that will look Human Skin like.
The subtle fingertops and redness going into the ear combined with the fact skin now looks very organic and human like in tone is what SSS is truly about.
Perhaps it's okay, but i dont think light from the background is supposed to traverse the whole torso or skull. I assume if it's rendering like this when transparent background, then light is behaving the same way when the background is rendered (but it's just more difficult to tell?)
I will try playing with settings more to see if can remove that issue while keeping things looking okay.
I typically ignore it, knowing Daz, it will have issues, but this is the best you can expect.
Under render settings you have Alpha, and i just put that on Primary, you can do custom, but no idea how or what exactly goes there.
My Polyhaven outdoor HDRI's seem to be rendering very dark, so i can't currently use those in the Beta Build. however, the rest seems to be exactly fine.
I've got those issues even with the pbr skin, looks like an alpha problem because it happens only with transparent background.
Yup, i'm only aware you have an "Alpha" option under render settings which may perhaps help with that.
Also, apologies for not answering the previous questions.
My Master skin shader is based on the same principles as Omnisurface, but it's not using it. Same for my Master Hair shader, based on the same principles as the Omnihair shader, but for non-strand based hairs specificly. (My Master Hair shader will apply just fine on strand-based, but the parameters will not work as intended)
However, while the original plan was to sell the Master Shaders, i yesterday just dropped the ball, and decided against that.
Is this a map from global skin? the albedo details on the hand are nice.
Nope.
Here is how i make my Scattering Weights.
In Gimp (will work in photoshop too), i create a Square texture of 4096 by 4096, and then fill it with the Color 200, 200, 200.
Then i grab the diffuse texture, drag it into Gimp so it creates it as a new layer. Then you either desaturate it until it becomes a Grey scaled images, or you make it a Grey-scale image by converting it.
Invert this, and then add transparency to it, don't make white transparent, but aim to extract the grey details until you are about only left with the white details. Then flatten/Combine the maps, and you now have a "Cavity based SSS map".
how mine look like. I do it this was because white on white means you won't see it, and because i also want those maps to actually take the diffuse map into account, so that they are alligned with it.
Curiously, even when i put something behind, it still results in strange alpha problem. (Example was rendered with SSS Weight at 0.91 and Anisotropy at 0.88)
I guess I will operate on assumption it is problem with Daz.
Looks very interesting though. If it's not based on the omnisurface then you were right about the translucency, sorry about that!
Why did you decide to not sell it anymore? New shaders are always welcome, especially for skin!
That is very strange. Did you set the alpha to primary in render settings? I'm pretty sure is something in the render settings, but I don't know what can be. Also that model looks amazing (with or without omnisurface). Is the one you are about to release?
That's not 100 Percent working though, but i tried to look there.
And the reason as to why i'm not selling it anymore, a unneccesary discussion spiraled out into discord about this subject. The Daz Community is not ready for this. It are only a handful of people willing to take the steps required to actually attempt and render skin as photorealistic as Iray actually can render it as.
The Default out-of-the-box vendor Presets all seem to have the common issue where the Anisotropy of scattering is by default set to -.70, with .85 translucency weight. I've messed around for way too long with those shaders, and also trying it out with those exact maps i've shown and both of you use, the results are off, and Both Iray Uber and PBR Skin are struggling to actually render those maps correctly.
Setting it to 'Primary' or the default 'Specular and Tranmission Objects' doesnt really seem to fix the issue.
I mean it looks like trash but yes i will release soon. (Maybe not with this shader, I hasted to add...)
Can't wait to get that trash!!!
I tried your settings but it looks too bright on my model... anyway the anisotropy set to 0.85 seem to gave the best results for skin. I'm still not sure about the weight though, 0.9 seem too much for me.
@dbmelvin1993 Thank you for the explanation. I spent months trying to get realistic skin with uber shader, eventually I gave up. The best I got you can see it in the picture. The problem for me was the translucency, ok for bright skin but with dark skin just disappeared. I never found a way to fix that.
I seem to be getting the transparency issue for any positive value of anisotropy above 0 (regardless of SSS weight or SSS scale), it's just much less noticeable at 0.4 than at 0.85 for example.
Does anyone else reproduce this issue?
i see.
Well i'm busy now with other things, but glad it helped.
Are you saying here that you experience the same issue with the anisotropy forward scattering setting giving weird transparency effect in renders?
Yes, i do have the same issue, so it's not specificly shader related. you seem to get that with any shader.
though it would seem that in certain instances it does not happen, maybe it's HDRI related.
There are some settings and map examples for omnisurfacebase used here but annoyingly they havent used SSS anisotropy: https://docs.omniverse.nvidia.com/workflows/latest/rtx_rt-dh-setup.html
Seems SSS bug has been occurring previously on other shaders: https://www.daz3d.com/forums/discussion/comment/7145751/#Comment_7145751
I'm not sure it is a bug, maybe it's just like alpha volume is supposed to render. I noticed if you replace the volume surface on the material the alpha transparency is gone, but the render result is different unfortunately. Duplicating the layer will fix the problem, but I don't think is the correct way to do it. I think you have to use a custom LPE to create the alpha channel for the volume, but I didn't find a way to do it.
It still is a very interesting documentation, showing a lot of values, and, also that the SSS weight indeed goes into the SSS Weight, but more importantly, it show that the SSS Weight is actually only the green value of a Roughness/Specular combo that are an invert of each other.
For the Scattering Anisotropy i would not worry, as high forward scattering for human skin is pretty much been reported with many other things, like for example, Pixar Studio's (and they also delve into the idea of Multi-subsurface scattering)
The weight map is indeed a nice touch, it create more variations on the skin which is good. If there was a way to use separate channels of one texture I would have use it (it's very common in games). I want to try if it's possible to do it with the Shader Mixer, I would also like to have a specular weight map.
I belive it is possible to unpack a packed map in shader mixer, as I looked into it several years ago, but I may be misremembering. It's not a simple split RGB node like in blender, it's something like a split XYZ where X,Y,Z are interpreted as RBG. I would assume there are discussions on the forum about it.