[bograt]

Hello All,

Maxwell render is by far my favourite rendering engine and I have always loved how versatile and accurate it is, especially considering the stacked layer system. I have always found it is capable of achieving the results I am looking for, until now.. maybe...
Basically I want to make a good skin material, Making a soap like sss material is simple but skin is obviously far more complicated than that, The 3 main layers of sss the skin is made up of seems very difficult to achieve using the material editior (version 2.6)
I have tried many ways to recreate the 3 layers (bloody dermal, sub dermal and epidermal) of skin such as:
3 bdsfs weighted to achieve the 3 varying layers,
3 semi transparent layers each with a bsdf,
1 layer with standard sss and 2 with single side
the list goes on....
The real problem is that epidermal and sub dermal layers are very thin so their effect is very limited and only have an effect for less than half a mm, Unless I want to make a wax model I am going to have to come up with a way around this problem.
mental ray has a 3 layer sss system in it which works very nicely but mental ray sucks.
Maxwell has a very nice hair system so unless it was intended for wig product design, there must be a way to produce hyper real skin?
any suggestions are greatly appreciated, or if anyone knows more about how the stacked layer system works with sss materials than is mentioned in the users manual?
Cheers,

Jules

[Mihai]

The current volumetric SSS although accurate is not suited for skin, like you said because it's not possible to limit the effect to very small scales, and also because it's not possible to map the SSS, only thinSSS is mappable. I can't really offer a solution for now, although it would be interesting as a test, if you modeled a thin surface of 'skin' and right beneath it you put a regular non SSS surface so the SSS has something to stop against...

[bograt]

Thanks for the reply,
That's a shame... Urgh! I dread the thought of ofsetting a complex model like a head (though I have considered it!) It is funny because I almost believed I could do it by using multiple layers each with varying opacity of single side sss and one solid sss (as long as there was at least one was on 100%, wierd stuff happened if not)
You did a very nice render human hair! wouldn't you like to see some nice skin shading to join it?
well I really hope one day this will be possible, I have always considered Maxwell render to be a way of simulating real life, rather than just a rendering engine, and this would really take things to the next level!
I don't know if any material editor developers from the next limit team will read this, but if so... I recommend either a 'multi layered single side SSS' option, or simple allow the 'stacked layer system' to accurately simulate stacked 'single side sss' layers .
When that day comes, I will be a happy man !

[Mihai]

wouldn't you like to see some nice skin shading to join it?

I dream about it every day

[eric nixon]

WIP, not my model or maps of-course.

[Rob_Lucy]

Wow...
The best Maxwell skin solution I've seen so far.
Only the nose has a bit too much transparency.
Is that a SSS or a thin SSS material?
I'm asking because I know the model has to be watertight for the SSS to work, and I would like to use Daz models which are not watertight...

[eric nixon]

Thanks, theres a tweaked one I'm cooking now...will upload soon.

Yes indeed, the nose needs some kind of cartilage geometry inside, I might try a blob of lambert glass in there.

Thin-sss?? but that would only work if you wanted to render an inflatable person.. like a blow up doll perhaps

[Rob_Lucy]

Blow up dolls, exactly.
Thin SSS works with them because they're not watertight, right?

[eric nixon]

update;

[bograt]

This does look good,
Thin sss works well in some cases because the epidermal layer is very thin and fairly consistently even, the red light scatters deep so standard sss would work well for this wave length but yellow and green for example scatter fairly shallow not to mention the blue light which doesn't really scatter at all (or to look at it another way, scatters so much that it barely leaves the skin),
I think you have done a good job here but there is always a trade-off between the translucent scattered look and the diffuse nature of skin,
Simply a combination sss and this sss could yield amazing results but I have discovered this is not currently possible.
keep up the good work though, Have you tried additive diffuse layers in there?

[sandykoufax]

cool! wanna see other view angle like ear view.

[eric nixon]

Thanks for the comments guys.

Bograt, your idea about putting a thin-sss object around another transparent object (not sss though) does work for some things, it works well for thin-skin objects like a grape or tomato, you need to use lambert roughness for the transparent object inside, then it will render quickly. Actually for a tomato I just make the inside material bright red diffuse with an R2 and dark R90 to create darkened edges - pretty much like the diffuse part of a car-paint mxm.

7 min render sl15


Heres a scene; http://minus.com/lyDr8zdbkTeoq
I didnt include the texture map (used on both the skin and the 'lambert glass' inside), but any grape like texture setup for spherical mapping should work, anyway its just an example scene, (in which you'll see that the gap between the objects is tiny) just put any texture for testing.

I did a test with sss (lambert is no longer helpful - I used roughness 50) It renders a bit slower, about the same as a roughness-50 glass material would BUT it doesnt work with a bright sun HDRI, Its also possible this shape is far to simple to test this properly;


Latest head render, these renders are a bit slow and unconvincing for close-ups, I would consider it a useful mxm for background people. Eventually some genius will devise a multilayer sss shader, until then just dont render faces!

[eric nixon]

I've decided this doesnt work well considering the render times, sometimes you just want things to work and become convinced it will.
In theory if there is a need to render skin, I think its better to use a simpler skin material which renders faster, and hope motion blur + dof is enough for a convincing look.

[bograt]

Eric your latest skin looks really good, I think you may be right considering render times. Most people render skin in mental ray and comp it in to Maxwell scenes but this seems like such a shame considering the power of maxwell.
I guess I will have to wait a bit longer for true skin realism in maxwell, Its all because we as humans are so good at recognising human features.
I'm waiting NL Team!