True skin?

[brammelo]

Hi Ikeda,

There's a sharp line between skin and lips. Is this because you didn't cover the lips with the translucent layer?

It has a bit of a velvet shine to it, and if I recall correctly, this can be done with a single shader, isn't it?

Cheers,
BaRa

[AdamT]

Looks okay, but I think you're better off using a single material with Chanlum or Arndt's translucency shader in the luminance channel (for SSS fake).

It does look too shiny and a little metallic. Maybe use Blinn or Oren-Nayar instead of Phong. I'd use a specularity map in the specular color channel to vary the shininess (more on the forehead and nose and less on the cheeks).

Interesting experiment.

[H. Ikeda]

Hi brammelo,
Thanks for quick reply.
Originally posted by brammelo
There's a sharp line between skin and lips. Is this because you didn't cover the lips with the translucent layer?
The lips area has been textured with another restricted shader for polygon selection, so simply I didn't cover the fringe with the texture for lips. I'll correct it.
Originally posted by brammelo
It has a bit of a velvet shine to it, and if I recall correctly, this can be done with a single shader, isn't it?
This includes two heads, and a slightly larger head and an original-size head are overlapped. If you mean each head has a single shader, yes it does except for lips. The inner head has a simple shader, color of which has been uv mapped with an image, and the outer head has a banji. Maybe the velvet-like highlight comes from the banji, its specular, diffusion and roughness.

Cheers,

[H. Ikeda]

Hi AdamT,

Thanks for comments.
Yes, sss shaders may be better. I expected a real thin layer between two heads generates some effects of scattering, but it may not be the case since it's a bit metallic as you pointed out. But this may be adjusted with parameters of the banji...I hope, and need some workaround. :shrug:

[flingster]

heh heh....
H. Ikeda: love reading your posts bud...mainly cos you are always trying something different....keep it up bud.:thumbsup:

btw is there any form of sss shader/plugin about out of interest?

[Caravaggio]

I always wondered if layered skin wouldn't be better, if more processor intensive.

Did you just scale a second model or did you use the makethicker plug-in? I wonder if the same thing couldn't be done with fusion.

Personally I'm still waiting for someone to come up with a way to make the skin "slide" over the bone. You know, like when you move your jaw the skin at your chin just barely moves up as the whole chin is moving down instead of being a complete slave to the way your character is boned.

[Per-Anders]

your underlying layer needs to be a warmer color to my eye. there's no life to the skin, it's got that solid bronze look to it currently. maybe augment the transparency with the tinyest ammount of fresnel and a little noise.

i've found that for a simple skin with procedural only a light brown yellow is needed in the colour channel, actually a fairly cool colour then in luminance a really deep brown red, and the specular very very low and wide, but specular colour to the complimentary ofthe skin, so a blue. anyhow all of that seems to be a good starting point, then it's a case of adding in noises and stuff (if i'm doing it procedural only) also to fake the slight amount of fur and some depth to the skin without using SSS or another layer i often use a subtle glow on the skin, which both softens out any artifacts or problems with the mesh and gives a feeling of warmth to the skin, making it more tactile.

[H. Ikeda]

Thanks for the comments and suggestions.

flingster:
Thanks. I know something different is not always good, but at least we have chance to get better understanding.
As for SSS shaders, do you mean other than Chanlum and Vreel's?

Caravaggio:
Of course this takes more rendering time than without a skin layer, but I think it's within a reasonable range (partly because Shave takes much more time...:)).
I just scaled a second head in the model tool mode, simply writing multiplications like *0.95 in the fields of the Coordinate manager.
Maybe you're right about Fusion currently. If an effect of the skin layer is only the addition of color, specular and diffusion of the banji to an underlying color texture, this is nothing but that of Fusion... I expected more, but it seems little...

As for facial muscles controlled with bones, there is a muscle model as an application of the finite element method (in Siggraph). Someday we may use it in c4d using a much more powerful computer.

mdme_sadie:
Well, that's bronze-like, that is, metallic one and need color. Ok, I'll try doing them. Also about some adjustment of banji.
Blue specular color and a little glow are cool. I'll also experiment about them. Thanks again.

Cheers,

[kiwi]

If I remember rightly each character in FF had a skeleton,then veins and arteries,next musculature,and then clothes,and all layers were separate.



The thing that I have found very important in a skin shader is diffusion,you can have everything set up brilliantly,but if the diffusion is not right it will ruin it.



I am thinking of trying patchs as opposed to a full head,and make the patches luminous to mimick underlying veins and cappilaries and the areas where there are more of them.



Stu.

[H. Ikeda]

Hi kiwi,

Thanks for the comments.
The most important thing in skin textures is said to be scattering process within a skin layer. This means the scattering changes diffusion process on the surface of a skin layer, so diffusion might be important as you pointed out.
Ok, there may be two approaches to a realistic skin, using special shaders (SSS shaders, of course) and using anatomy-based modeling and texturing.
Are you trying the latter case, or some special shader?
Anyway, looking forward to your results.:)

[kiwi]

I am going to try anatomy based :)



I think a realistic skin is a result of good lighting,good texturing,and understading the materials.I went through some of Leighs texturing for dummies threads again last night and picked up quite a few new tips for skin,check them out,especially the new diffusion one :)



I have not finished modelling my head yet to try the experiment,but I have a skin shader already which is one Phasmatis sent me and I added some tweaks to it as well,works quite nicely,we just dont have the ability to zip anymore here or I would attach it and I am sure evryone here could make add something and make it really rock.



Stu.

[AdamT]

Hey Kiwi,
Where can I find Leigh's tutorials?

[kiwi]

I meant the texturing for dummies series,but actually I spotted a UVW mapping ute as well in the texturing forum here at CG Talk.



Stu.

[AdamT]

Originally posted by kiwi
I meant the texturing for dummies series,
Stu.
Okay I'll bite, what's the texturing for dummies series? :rolleyes:

[kiwi]

Ah youre winding me up arnt ya?.......they have been there for 6 months or so.



If not in the texturing forum Leigh has written up really informative chapters on the ways to use your reflection,bump,diffusion etc channels in a material or when painting them.Its really good indepth stuff that goes to the base of how reflections come about,what diffuse is etc etc,you gotta check it out.They are also on Lieghs site in PDFs as well I believe.



Stu.

[H. Ikeda]

Thanks kiwi,

I've copied the workshop sticky threads, from part1 to 5. Great stuff, as if it were a book! Maybe also AdamT has found it.
For skin texture, part4 can be useful as you suggested. Now reading...

Cheers,

[H. Ikeda]

Ok, some updates here. c&c are welcome.

First is for a double head (which has been shown in the first post) with a skin layer.
Speculars and diffusion of banji (applied to an outer head) have been modified.
Also color and specular in underlying texture have been adjusted within each channel. I think it's less metallic and has somewhat better color.

http://www.interq.or.jp/aquarius/ikeda3dr/data/cgtalk/skin_layer.jpg

Next shows a single head case with a SSS shader (Arndt's Translucent in fake mode).
A noise (similar to bump with blur) in diffusion, of course the SSS shader in luminance, and blue specular color. This seems not bad, though something detailed seems missing...

http://www.interq.or.jp/aquarius/ikeda3dr/data/cgtalk/fake_sss.jpg

Last is using kiwi/Phasmatis's skin shader for a single head. The shader has been tweaked and modified for this purpose (in particular, no reflection). It's without SSS shader.

http://www.interq.or.jp/aquarius/ikeda3dr/data/cgtalk/kp_skin.jpg

And kiwi & Phasmatis have allowed me to link the skin file (with tan): Skin.c4d.zip(24K) (http://www.interq.or.jp/aquarius/ikeda3dr/data/cgtalk/Skin.c4d.zip)

Cheers,

p.s. kiwi: another zip file (other than tan) seems to be broken...

[flingster]

having no experience of skin texturing at all...i'll give you me thoughts....by the way thanks once again for keeping us informed and updated...as it gives us all an insight into the whole process.

the top one seems to dark (smooth, uniform, sootty) in areas. but it like the shiney areas of the skin on that one as it seem more in keeping with the greasey areas of a persons face.

the middle one...i quite like the colouring...but is almost doll like in its qualities.

the last image i like the colouring and seems the most life like out of all of them...i would like to see slightly more of the highlighted areas of skin...giving the greasey patchy areas of skin as in the top one....however i think i like the bottom one the most out of all of them.

how about blemishes...moles...scars...wrinkles...how would you go about adding them....hand draw them from reference or what? dunno thoughts anybody...

however i can't help you with any of the settings that need changing...:thumbsdow ....cos i don't know what the hell i'm doing! sorry can't be more useful here....but i'm gonna download your file and take a look....like the way the whole process of experiment has come along....eg hair thread, eyelashes, skin etc very informative.
keep it up bud....youre certainly getting results and seem to be gaining a lot in the long run...as are the rest of us on this forum.....:thumbsup:

[Phasmatis]

Here's another version, I haven't tried it on an actual head yet, I haven't had the time. I think it still needs a bit of work but it's getting there.

http://www.imgmag.com/images/phasmatis/Skin.jpg

Here's the file. (http://www.planetdeusex.com/tnm/phasimages/skin.zip)

[kiwi]

That looks nice Phas :thumbsup: ,a bit to specular for my liking though.


Hiroshi the other file was probably just a folder evrything was in,I find that happens sometimes as I use a Mac,so I dont think anything was corupt except the folder itself and not its contents.



A good friend told me they have skin shaders over on Treff.de as well.




Mdme_sadie also sent me a new base skin shader this morning so I will pass that on as well,and if we combine all our efforts we should be able to get a nice shader.



The veins bump in my example guys was just for an experiment on the sphere and didnt work properly.



Stu.

[ThirdEye]

Phas: it's good but specular should be blueish ;)

[Phasmatis]

I've dulled the specular a bit and made it blue and it looks better. I'll post a picture soon... I think the problem is, there isn't any specular on the bumps and I'm not sure how to do it.

Arrias is also working on a shader so we should really get somewhere with all of us working together. :)

[Phasmatis]

Here's (http://www.planetdeusex.com/tnm/phasimages/phasskin.zip) the latest version.

[Arrias]

I've put some renders up of what I've done so far, they're built off of one of the earlier ones phas sent me, I'll link to them to save us 56kers some bandwidth ;)

Paler one (http://darkt.zapto.org/paler.jpg)

More Tanned one (http://darkt.zapto.org/tanned.jpg)

And I also made some radiosity renders which looks a lot better IMO.

Paler one with radiosity (http://darkt.zapto.org/paler_rad.jpg)

More Tanned one with Radiosity (http://darkt.zapto.org/tanned_rad.jpg)

Any pointers anyone has are very welcome :D

[ThirdEye]

Here's my 2nd head (still a wip), i'm working expecially on skin now but yes, i followed a traditional approach with 100% hand painted maps in color, bump, reflection and specular channel fused with bhodinut hue or fresnel in certain situations. The trick is chanlum in the luminance channel ;)

[H. Ikeda]

It's great, ThirdEye! Nice painted. It seems that a SSS shader is 'must.' In Luminance? I'd also try.

And thanks for the discussions and links.

Hmm...now key word may be 'specular.'
But as for my head here, an early-teen girl that is rather a doll-like character, too much specularity may be strange because it's close to baby's skin. I can't imagine oily-faced baby.:D
Of course, the previous heads need more specularity, though.

Ok, this thread will continue being updated until we have some basic skin shaders (for head)...maybe. Well it seems to need an application to a head to check how it looks like, e.g. shading, shadow, specular... I'll do this in some part, but modifications will be done for the head model (maybe low specularity).

As for Phasmatis's shader (thanks for the links), it's nice and beautiful but I wonder why it's 3 layered instead of 2. And in the settings of specular, 'colored' option seems better than 'plastic' so that the diffusion affects specular color, but this may be a matter of liking.

As for Arrias's rendering (also thanks for the link), it's cool and I'd like rather non-radiosity one. Specular in radiosity looks like over-exposure IMHO.

Cheers,

[Claudio72]

is there anybody of you use fresnel in the transparency channel?

I'm digging some exps with fresnel in transparency and banji in luminance

as soon i get something I will share

[flingster]

cool thread guys....can really see the changes and mods people have experimented with improving everyones works...so full marks to you all!!!:thumbsup:

Arrias: i think the paler with radiosity is fantastic....even spooky...even if it is a bit bright....still think thats the best one of your tests.

ThirdEye_01: very impressive....like the lipstick/lips colouring very nice indead....and overall its very cool bud....when you say handed painting are we talking cloning areas of good photographic images...or are we actually talking painting...cos surely it could be more effective blending different photos of skin from the say the same model? dunno....how did ya do it? any tips would be cool bud...like say veins...or which channel you put them in etc...thanks.

[NWoolridge]

I've struggled with good skin; I'll try to dig up a complicated SLA shader I worked up that had pretty nice looking subtle veins under the skin.

Here's a test of Shave and a Haircut with some attempts at reasonable skin. There is a bit of SLA fresnel with Falloff masks to sweeten the edges...

Nick

http://www.bmc.med.utoronto.ca/c4d/testhair.jpg

[ThirdEye]

Originally posted by flingster
cool thread guys....can really see the changes and mods people have experimented with improving everyones works...so full marks to you all!!!:thumbsup:

Arrias: i think the paler with radiosity is fantastic....even spooky...even if it is a bit bright....still think thats the best one of your tests.

ThirdEye_01: very impressive....like the lipstick/lips colouring very nice indead....and overall its very cool bud....when you say handed painting are we talking cloning areas of good photographic images...or are we actually talking painting...cos surely it could be more effective blending different photos of skin from the say the same model? dunno....how did ya do it? any tips would be cool bud...like say veins...or which channel you put them in etc...thanks.


100% hand painted, no photos at all, it's funnier and you don't have resolution problems. For veins i rendered a floor with bhodinut 2d noise then i ported it in Ps as a .png file and played with opacity and eraser.

[flingster]

cool...thanks bud..appreciated.:thumbsup:

[kiwi]

Phas did you incooperate the shader Mdme_sadie sent to me as a base shader,it was really good :) .I couldnt tweak the shader or play with it much as it was an 8 file :shrug:



Nice skin guys.But to my mind the examples are all way to specular.When I look at skin the light is diffused so accurately across its surface,which is why I used oren nayar and not blinn.Blinn being for shiny surfaces.Also the examples look like they are under very hot lights which does not look natural to me.



Stu.

[kiwi]

I was making a new skin shader yesterday and the frigging power went off before I had saved it :annoyed: ,anyway heres a new one which is mainly based on Per {Mdme_sadie} version.I also added etra layers of bump,would like the bump more blurred and smooth,but here waht I came up with anyway.



Stu.

[Phasmatis]

Oh sorry, I meant to reply to you but I've got a million things to do and I forgot :hmm:... I think you sent my shader back instead of Mdme_sadie's.

I'm not going to have the time to work on it that much for moment, I'm still working on that taxi thing (plus a few other things). Once I get things in order, I'll get back to helping make skin. :)

[Arrias]

Originally posted by H. Ikeda

As for Arrias's rendering (also thanks for the link), it's cool and I'd like rather non-radiosity one. Specular in radiosity looks like over-exposure IMHO.

Yeah I found that when I dropped the radiosity strength down a bit it actualy got rid of a lot of the glare which helped it a lot. If the specular was lower and thinner it probably wouldn't have looked too bad in that respect.


Originally posted by flingster
Arrias: i think the paler with radiosity is fantastic....even spooky...even if it is a bit bright....still think thats the best one of your tests.


Thanks :) I didn't intend it to come out like that but it's still a nice effect it gives.


Originally posted by ThirdEye_01
100% hand painted, no photos at all, it's funnier and you don't have resolution problems. For veins i rendered a floor with bhodinut 2d noise then i ported it in Ps as a .png file and played with opacity and eraser.

Damn I look forawrd to the day I can do that!

It's really good, all the blotches seem to fit, it's got a good specular on it (something I'm having a hard tiem achiving), the blemishes etc. look right and on top of that the colour looks great!
*takes hat off to you* not that I'm wearing a hat but it's the thought that counts ;)


Originally posted by kiwi
Nice skin guys.But to my mind the examples are all way to specular.When I look at skin the light is diffused so accurately across its surface,which is why I used oren nayar and not blinn.Blinn being for shiny surfaces.Also the examples look like they are under very hot lights which does not look natural to me.
[/B]

Yeah I was using blinn because orean-nayar wasn't giving me the effect I wanted but after dipping bakc into the manual and tweakign it a little I got the effect I wanted.

____

Unfortunatly I don't think I can get the one I'm working on any better than it is without ruining it so I'm going to start again.
I've uploaded them here (http://darkt.zapto.org/skin_arrias.zip) for anyone who wants to use them (if it doesn't let you download it then go through here (http://darkt.zapto.org) and click the link on the page :) ) but they aren't exactly brilliant & look far too plasticy IMHO.

And here's a quick render of each of them:

Pale (http://darkt.zapto.org/pale_final.jpg)
Tanned (http://darkt.zapto.org/tanned_final.jpg)


PS. Sorry I've only uploaded an r8 one but if anyone wants I can probably convert it to r7 later on today :)

[H. Ikeda]

Nice skin ball, kiwi. So which noise for the bump?

Well, here's a test rendering with the latest Phasmatis's shader modified for this head and with Shave hair.
Color has been modified and combined with a uv-mapped image (using Fusion), and specular has been also adjusted since its option is 'colored.'

[H. Ikeda]

And, before we go forward, some questions arise:
- What is the best shading model?
- With or without a SSS shader?
- Which noise is the best for bump?

First comments:
- Many people say oren-nayar the best shading, but its detailed settings can be different. I was also using it for head shading just like; Diffuse Falloff -10%, Diffuse Level 105%, Roughness 20%; While Phasmatis uses DF -30%, DL 100%, R 50%. Maybe these should be within some range.

- Probably we could get good results for both with and without a SSS shader, after some fine tuning. The SSS effects seem to be safely faked with Fresnel and possibly Falloff.

- About a good noise, we could see some candidates in the linked files as below. Probably voronoi family (possibly combined with other noises) might be suitable.

Any further comments are welcome.
Also any idea or results about skin shader...:)

[Phasmatis]

That looks really nice, could you post what colours you used? Because they are a million times better than the ones I used. :thumbsup:

I forgot to reply to your question before so I'll do it now. :) The reason I used three layers is because I wanted the middle layer to have more luminance than the other layers to try and get the effect of light under the skin, I have to admit I didn't try just using two layers, only three, did you use all the layers in that picture?

[H. Ikeda]

Yes, that uses a 3 layered one, and color is also not so different from yours. In fact, rendered color has been adjusted with light's color, somewhat yellow.:)

Anyway, post the shader file: skin_phmod.zip (20K R8 file) (http://www.interq.or.jp/aquarius/ikeda3dr/data/cgtalk/skin_phmod.zip)

An image for uv mapping has been replaced by dummy file.

Cheers,

[flingster]

H. Ikeda: that head of yours is really coming along....its amazing what subtle changes in textures/hair/lighting etc can really do to an image...much improved indeed! well done bud.
you kinda take it for granted really...but having seen that lady from the hair thread to now...shes really starting to get there!!:thumbsup:

[kiwi]

I will mail you the file Hiroshi :)



The bump was Mdme_sadies idea,you use buya for little imperfections which stick out,then I used just a bump channel as a second layer of random for skin pores going inwards,some distortion to your bump shader also works well.



Were getting closer :)



Stu.

[H. Ikeda]

Phasmatis, flingster: thanks a lot about the picture. But that picture owes much to the shader by Phasmatis. I just pushed it forward a little. If that becomes much better, the shader is heading for a right way, I'd guess.

Phasmatis: I understood the meaning of 3-layer textures. Also I'll check other cases such as 2 layers.

I'm now tweaking the kiwi/mdme_sadie shader, which I received from kiwi (thanks kiwi & per). The skin ball with it has been shown by kiwi in the previous post above.

For your checking: Skin_experiment.c4d.zip (43K R7 file) (http://www.interq.or.jp/aquarius/ikeda3dr/data/cgtalk/Skin_experiment.c4d.zip)

As a special feature in this shader, we can see veins on the skin surface. This makes the skin pale a bit. It's all right since we can change skin's color to compensate it.
But I wonder if we couldn't see veins through the skin of a head actually, in particular through that of a face. The shader itself seems to generate a good result though.
Anyway, I'll experiment about the shader, including modification of colors and lighting.

Cheers,

[kiwi]

For veins we need a blue tinge Hiroshi :)



I found some good bump settings for first skin bumps and second skin pores,try them they work quite nicely.


Stu.

[kiwi]

.

[H. Ikeda]

Thanks kiwi.
Ok, here's an example of the kiwi/mdme_sadie shader modified in a similar way to Phasmatis's.
In this case, Luminance has been adjusted and combined with an image for uv mapping. Lighting has been also changed so that the skin has a little warmer color. Bump settings are the latest. Cheers voronoi!

[kiwi]

Nice work Hiroshi :thumbsup:



Hey call me Stu :)



The bump is a little high bud.I would try the skin pores on about 10 - 15 percent,and the buya bumps on say 20 - 25,you will know that the setting is just right when you look at her face and its not really easy to see if she has a bump or not,that way you should have a sss type effect.


I have found that the luminance brings out the bump even more so,so you have to relax it even more.


Stu.

[H. Ikeda]

Thanks ki...Stu.:)

I know it's a little high bump, and I just did so because the main concern of that picture is how its bump looks like. But it seems somewhat too high in the picture.

Anyway, there are lots of kinds in skins, young/old, pale/tanned, dry/oily, man's/woman's...
In this sense, a high bump case may be also acceptable as a pimpled face or others.

But it's just the matter of a single parameter, i.e. bump strength.
We could easily understand.

So now, what tips do we have about skin shaders?

[kiwi]

Ya I agree about the skin type Hiroshi :)



I think now that the key to good skin lies in the luminance channel settings,its the part which adds the most.



Stu.

[H. Ikeda]

Sure, the luminance channel might be important, Stu.
And before that, I think first the shading model (oren-nayar) should be checked including its fine settings. This may be what had to be done though.

Well, I've just checked Phas shader about the number of texture layers.
Original picture has been shown in: http://www.cgtalk.com/showthread.php?s=&postid=356124#post356124
If the 3rd layer is removed, it's almost same as 3 layered.
If the 2nd layer is removed, we have a shader with less luminance, as we could expect.
And one layer (only the first basic layer) is almost same as the above 2 layers.

If it's almost same result, fewer layers would be desirable for less rendering time.

So we could have a modified 1 layer, as shown below.
I'm now not sure when applied to a head this also shows a similar result.

[kiwi]

That looks good Hiroshi :thumbsup:



Stu.

[Phasmatis]

That head looks great. Keep it up. :)

I just tried the skin with one layer but with higher luminance and you're right it does look exactly the same as the three layered approuch, I think I just got a little blind sided working on it for so long in one go, I saw the three layered one worked so I didn't want to change it. Which is why it's good if other people work on it.

It renders a lot faster now. :)

[H. Ikeda]

Thanks Stu and Phas.
Ok, I've also confirmed one layer texture surely shows an almost same picture as before. A little different color though. If colors are adjusted you couldn't distinguish two pictures (so not posted).

Now summarizing the links:

Phasmatis (latest); phasskin.zip (http://www.planetdeusex.com/tnm/phasimages/phasskin.zip)
A modified Phas; skin_phmod.zip (http://www.interq.or.jp/aquarius/ikeda3dr/data/cgtalk/skin_phmod.zip)
Arrias; skin_arrias.zip (http://darkt.zapto.org/skin_arrias.zip)
Kiwi/Mdme_sadie (latest); Skin_experiment2.c4d.zip (http://www.interq.or.jp/aquarius/ikeda3dr/data/cgtalk/Skin_experiment2.c4d.zip)
Also,
AndyB; 2SLAskins.zip (http://www.c4d-treff.de/ressourcen/download/sla/andreasbartsch/2SLAskins.zip)

I think AndyB's is for body skin rather than head.

Happy skin!

[AndyB]

Originally posted by H. Ikeda
...
I think AndyB's is for body skin rather than head.


Hi Hiroshi,

you're right.

Your skin presets are very interesting and condemned good.
I have many ideas to all the settings.
But I'm busy with 'my' injuries. Have still little patience, please.

BSY
AndyB

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