sub-surface scattering: The final frontier

[leigh]

Yeah, I have the same problem.
I use LW, and I can't an SSS plugin (not even the cheap ones, because my countrys currency is so weak).

I have also yet to find a decent way of faking it.
You can use things like gradients and stuff in conjunction with your lighting to create soft glows on the skin though :)
I mean, you mustn't think that just because you have no SSS, your skin will never look real, because people managed to do that long before we had SSS ;)

You could always model the actual muscle and and bone that lies within the skin, and just use normal translucency :p

[oddjob]

Originally posted by Leigh
You can use things like gradients and stuff in conjunction with your lighting to create soft glows on the skin though :)


Could you be more specific? Are you talking about something similar to simulating the fresnel effect?

[leigh]

Not the Fresnel effect, no. But just generally popping gradients in here and there and playing with them until you get nice edges :)

[Rice ManX]

I dunno much about this ither (i also use max 5) I think if you use the Translucency shader with your model and adjust the settings, it might turn out okay (ive never tried it) and i think if you use Radiosity it will calculate the correct subsurface scattering only if your using the Translucency shader. I dunno it mentioned somthing like that in the manual. Hope that helps?

[oddjob]

Yeah, I know that using global illumination helps to accent the effect. I'm still trying to figure out translucency myself (I should have noted in the beginning that I'm kind of a novice to texturing). Maybe I should re-read Leigh's thread. Again. For the 25'th time.

[smfjersey]

AMEN! This is the grail. I've been looking for this answer for SOOO long. I've started a few threads looking for help. even tried a few plugins. No help.

[oddjob]

Lets make it a group effort then!

If anyone out there has had success at reaching this affect or something similar to it, or knows of a great plugin, lets hear what ya got!!!

And in order to start off on the right foot, I'll be the dumbass to ask the question: Can we be TOTALLY clear on what translucency is (how is it different from transparency exactly)?

[AAbel]

There's a pretty descent subsurface scattering (faked) shader in SLIM format over at highend 3d. If you are familiar with renderman and the advanced functions of rendering engine of choice you should be able to come up with something pretty decent.

[aYs]

it's quite simple to fake some sort of sss

no sss fake
http://www.ays-arts.de/temp/sss01.jpg

with sss fake
http://www.ays-arts.de/temp/sss02.jpg


you just have to apply a gradient on luminosity for the incidence angle
that's all

[oddjob]

Well, to the best of my knowledge, Max doesn't have that incidence angle option (like I said I'm a texturing novice). Does anyone know how this would be applied to Max? I'm thinking I'd have to use the fresnel material for luminosity and THEN apply the gradient.

It looks like a great fake, but this seems to me to only work for still frame pics instead of animations. Am I wrong?

[aYs]

well, i can't tell you how this works in max but you also can apply it to animtions
as it uses the incidence angle it will always look good

maybe i will render a quick sample animation

[Ravennome]

You can access the fresnel through the falloff shader in max, which also allow you to use "incident angle (in LW)" or viewing angle properties. You can pipe your gradient through this or vice versa. That should help you get the effect that you are going after. I suggest using the raytrace material as well, even if your not raytracing, just cause you get so many more surface opptions for maps and shader pipes

Oh and don't forget, you can go far with some mulit-pass rendering and a little compisiting. Its very rare that production quality render come out of the renderer perfect, theres always a trick here and there.
.:bounce: so get going and good luck

BTW aYs, I love your Bernard, Maniac Mansion rules.:buttrock:

[aYs]

hey zainlars
we meet again ;)
we're a good team for all max/lw surface questions :wavey:

thanx, yes it roxxxx:buttrock:

[elukee]

how about these two fake 3s
;)

[elukee]

12345

[Stahlberg]

That's nice Elukee, does it work for skin too? What software is that?

Not sure if any of you guys saw my thread just below this one; my latest tut on human skin, includes how to fake translucency using a cartoon shader (probably similar to what was mentioned about the incident angle):
http://www.androidblues.com/shadetut.html

[oddjob]

yeah, that's a pretty interesting approach stahlberg. I think elukee is using the translucency shader for max, which i recently discovered too. It looks promising, but the trick is to make it look soft like skin and not hard like jade. I'll be tinkering with it and post any developments (if i can figure out how to post pics :)

[playmesumch00ns]

The best way to fake SSS is layers, similar to Stahlberg's recent tutorial and his previous miscellaneous notes (very interesting reading btw man). It's the same way they did it in Final Fantasy (and whatever you say about the movie, the skin looked pretty damn nice - ignoring the bad facial animation of course).

The basic idea is the same as stahlberg's but with knobs on. Instead of just the two layers, you have about 17, covering specular highlights from all angles as well as internal reflections from various different layers which all contribute their little bit. Now this is a lot easier to do in Renderman SL than in a package such as Maya, but you can do it. I haven't implemented it yet. In case you're interested there's a discussion in one of the Siggraph Renderman Course Notes papers over at www.renderman.org/RMR , as well as lots of other rman loveliness. I think it's the same one as where they chat about the volume shader they used for the invisibility reveal shots in hollow man (now there's some impressive shading work!)

[elukee]

The figures i posted are what i saw in chinadv.
The method to it is translucency script in max which can be downloaded from www.scriptspot.com while the process is too complex(in my opinion).

[Veggie_Iller]

I've tried to create layers to get realistic skin. But the renderingtime rises alot. And even when I get it to work ok or use real sss I still have to mix it with a shader. And even then there is a part missing that i cant put my finger on...

[Fungusmonkey]

I LOVE that tut, Stahlberg!!! I've been reading (and re-reading) it for hours now and trying to get the same effect in LW, but I'm nowhere near figuring it out yet. I got it figured out in MAX pretty easy, but it does me no good there, because I'm a total Lightwave fanatic and I use it for everything.

I'm not sure how to create a "incandescent channel of a new transparent Lambert" in LW. Any idea how that translates over to LW, anyone? (Leigh, I'm looking in your direction :D ) Also, how do you get Blinn and Phong, etc.

Maybe I'm headed the completely wrong way on this, and theres an easier way, but I'm still working on it. Maybe BRDF?? I don't know. This is the holy grail of CG.... Where's Indiana Jones and his Dad when you really need them?

:thumbsup:

[smfjersey]

O.K.,..now it's time to give up the info. You LW users have been holding out on the SSS secrets for long enough. I think now would be a great time to free yourself of burden of this secret. Leigh, I'll pre-order your book. Anyone, For god sake.
Oh,.I've seen it. I know it's out there.

[FatAssasin]

I put together a quick skin material using Max. I think the trick to faking SSS is using the Translucency channel in the Extended Parameters section of the Raytrace material. Put a falloff map in there with the Shadow/Light falloff type. I put a dark reddish color in the shadow side and used the output section to cut the output amount in half so the effect wouldn't be so glaring. You can achieve the same kind of effect using the luminosity channel but a problem arises in low light situations because the model will appear to glow.

I also put falloff maps in the diffuse channel to simulate how skin seems to become more gray on the sides and more saturated in the front. And then another falloff in the specular level channel to simulate the difference between glancing light and diffuse light, like Stahlberg talks about in his tutorial.

Of course, you'd need more than one texture for different parts of the face to get really believable results. Like a shinier version for the forehead and nose, and a more red version for the cheeks and ears.

I can upload the Max material if anyone is interested.

[Greenlief]

Maybe this can help? Not sure though, just saw it while browsing. Don't even use Lightwave myself. ;)

http://www.lightwave3d.com/contests/dec-02/winners/Tutorials/Layout/Shawn_Sapp/index.html

[Fungusmonkey]

I've been working more on a Lightwave skin shader, and I've gotten a little farther. Emphasis on "little"...

I was looking for an easier way to fake this, but I guess there is none, so I just started throwing gradients at it. Yay LW!!! It still doesn't look like I want, or even at all photorealistic, but it's a start, I guess. I'd get it to look okay in one lighting setup, but then when I'd move the lights, I'd have to start from scratch again :annoyed:. Here it is, but don't even ask about the settings, because you don't want to know... :surprised

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