Skin Shader study

[Julez4001]

Fantastic image you have going on for your skin study.

Can you post images of your Photoshop layers with the layer setting (multiply, screen, etc) and intensity?

[chikega]

Very interesting approach to create multipasses and reassemble everything in Photoshop or perhaps After Effects if it were animated. Very cool, Tony. I remember Maria when we first started posting on the Silo forum. And I remember your skin studies in C4d as well. Time flies when we're having fun, I tell ya'. Thanks again for sharing your experiments. Always inciteful as usual. :)

[popol]

great test tjnyc!!

[tjnyc]

Fantastic image you have going on for your skin study.

Can you post images of your Photoshop layers with the layer setting (multiply, screen, etc) and intensity?
Thanks fellows!

0. Color Layer
1. The vein layer was screen about 50%
2. Specular was screen 100%
3. Fresnel-Grad was screen 100%
4. Ambient Reflection layer was screen at 100%. I also lowered the saturation about -25
5. Occulsion layer was multiply at 100%. I lowered the saturation all the way down till the image was black and white. You can play with the brightness/contrast, but I didn't in this case. I would if I wanted to match a bright day with over exposure from the light .

Cheers,

[Julez4001]

Thank You!



Do you have anymore information on your IBL cheat?

What was inthe render that you lacking and had to come up with your own method.

Did messiah lack something or just frustrating to pull it out. How would you animate using your cheat? Rotoscope?

[tjnyc]

Here is an update.

I used a blurred HDRI image map. HDR prefilter ON with HDR intensity at 0.4. No Bounce Light GI, MC 6, depth 1 and GI Nosie reduction at Photons 500000, radius 100, count 400. Took about 30 seconds to render. I like the result better as it is less waxy than the previous PS blured indirect illumination layer.

http://www.telescript.com/images/tony/skn6.jpg

Julez, the IBL cheat idea I was referring too comes from this article.

http://www.andrew-whitehurst.net/amb_occlude.html

I didn't follow the whole approach, but what I did with the HDRI was to get my indirect illumination from the HDRI environment map.


Cheers,

[tjnyc]

What was inthe render that you lacking and had to come up with your own method.

Did messiah lack something or just frustrating to pull it out. How would you animate using your cheat? Rotoscope?Hey Julez,

I don't think it really is a matter of what the renderer is lacking, it is just the nature of the beast. Here is another shot with some color correction on the indirect illumination layer. Using a compositor to make these changes over re-rendering saves alot of time. By rendering the indirect illumination layer separately I have greater control over matching it to a live-action sequence or just improving the lighting without having to re-render sequences over again.

http://www.telescript.com/images/tony/skn7.jpg

Cheers,

[Julez4001]

Here is an update.

I used a blurred HDRI image map. HDR prefilter ON with HDR intensity at 0.4. No Bounce Light GI, MC 6, depth 1 and GI Nosie reduction at Photons 500000, radius 100, count 400. Took about 30 seconds to render. I like the result better as it is less waxy than the previous PS blured indirect illumination layer.

http://www.telescript.com/images/tony/skn6.jpg


Cheers,

I am curious in your HDRI pass because you choice of hdriimage or even your cheat before had a great "flesh" look to it. Its nice and warm. I am wondering what you would od different if say you had a sky and beach hdri map. You don't have a flat "texture pass" but your model looks like skin. The AON cell look pass contributing?

[flingster]

hey tony...i remember your c4d sla tests on this character...and its good to see a slightly different approach in messiah. i like the end result...seems a little specular/shiney in parts...some areas you really nail it stomach and neck i quite like...i like some of the luminous feel to some of them makes it more convincing for me at least...i think you vein layer really does the trick at first i thought it was a little over the top but when you see it in conjunction with the other layers it helps to flatter the image.
good work bud as always..keep messing.:buttrock:

[Sniffet]

Hey Tjync.


I would suggest the following for you ambient occlusion pass.. Set it to linear burn at 15%, create a copy of that layer, set it to multiply at 90%-95% or something.. Now go to curves for the multiply layer, and for the R channel set the blackpoint to 128, and for the green channel the black point can be 64 so it get a nicer brownish tone.. This way you dont end up with the "grey/black" shadows that usually is obvious with just a regular multiply. I atleast find it much better looking.

/Regards Peter K

[tjnyc]

Hey Tjync.


I would suggest the following for you ambient occlusion pass.. Set it to linear burn at 15%, create a copy of that layer, set it to multiply at 90%-95% or something.. Now go to curves for the multiply layer, and for the R channel set the blackpoint to 128, and for the green channel the black point can be 64 so it get a nicer brownish tone.. This way you dont end up with the "grey/black" shadows that usually is obvious with just a regular multiply. I atleast find it much better looking.

/Regards Peter K
Peter,

Thanks for the suggestion. The grayish issue was bugging me as it doesn't look right in an outdoor setting, but fine for indoors.


Cheers,

[tjnyc]

Another update, higher-res version than the last ones.

http://www.telescript.com/images/tony/skn8.jpg

Changes:

- Followed Sniffet(Peter)'s suggestion
- Created a better specular pass, really like the way messiah handles specularity, it usually is a b#tch in other apps to get it looking right.
- Brought out the vein pass more.
- Added freckles, subtle, but if you look around you will spot some.
- Got rid of the over wet/waxiness look.
- Slight PS glow.

I am pretty happy were this is going, need a texture map, some eye balls and teeth and we are almost in business.http://www.cgtalk.com/images/icons/icon7.gif

Cheers,

[tjnyc]

I am curious in your HDRI pass because you choice of hdriimage or even your cheat before had a great "flesh" look to it. Its nice and warm. I am wondering what you would od different if say you had a sky and beach hdri map. You don't have a flat "texture pass" but your model looks like skin. The AON cell look pass contributing?
I used the St Peter's probe HDRI map, but I think you could use any HDRI map and still get the same quality of "warmth" illumination. If I went with a sky, I would add a slight blue on the occulsion pass or create an ambient pass with a slight blue and multiple it with the occulsion pass. For the beach HDRI I would use it in my indirect illumination pass. If you know of a good beach HDRI map, I would like to try it out with this series of test.


Cheers,

[Julez4001]

Looking Great!

[chikega]

Getting close, Tony ... getting real close... :)

http://www2.victoriassecret.com/images/category/12-22-04/OSBRPZZZZZZ/ftr1.jpg

[Julez4001]

http://debevec.org/Probes/

Go here to get your beach hdri map...........

Julez out.

[tjnyc]

Here is what I got from the beach hdri. It was abit overcast, so I raised the brightness a little bit.

http://www.telescript.com/images/tony/skn9.jpg

http://debevec.org/Probes/beach_probe.jpg

Cheers,

[chikega]

I thought I'd keep things tidy by posting my skin studies here with Tony's. And it's also a way of bumping up his very informative thread. Julian posted a Maya SSS shader here (http://www.cgtalk.com/showthread.php?t=206199) which prompted me to investigate the subject matter using Taron's Basic Shader. This is the Butch character with a little more sweat applied, this is a straight render, no post work:

http://www.3ddmd.com/images/Messiah/ButchSSS2.jpg

[dobermunk]

Looks good! How many lights are in there?

[chikega]

Hey David, the scene has one spot light and it was rendered with GI. :)

[tjnyc]

From what I have been able to play with the Basic Shader is better than the Maya plugin and is very robust for all kinds of SSS skin creations. You can also mix SSS effects by applying more than one Basic Shader to a Final Radiance node to get some very interesting skin effects like the creature Gary posted on the other post. For example one SSS can be used for the inner sub-dermal skin with Extend-Shade or whatever and another SSS is blended in for the outer dermal skin with Extend Color. You could also use weight spots to define areas like the ear with a SSS to get the redish-vein shading, freckling and so on. Doing SSS skin shading with messiah I have found compare to others, C4D, XSI and Maya far simplier, better and faster.



Cheers,

[chikega]

One thing that the Basic shader doesn't do, that the built-in native translucency does, is show light falloff within the object. The whole object is lit uniformly whether the light has fall off or not. I've brought that up to Taron's attention. But, it can be faked to a certain degree using meta-effectors. See Julian's tutorial (http://flarenova.com/Msx/msx_sflow.htm). It would be great if messiah had weight maps to define areas of translucency as well.

[tjnyc]

Gary,

Faking can be accomplished in post, but have you tried blending a translucency standard material with a Basic Shader+SSS custom shader material to see what would happen?


Cheers,

[orion 77]

chikega, where did you get that pic of my girl? :D

[chikega]

I dunno about that girl, she was with this guy ;). Just testing out variations of the above shader - this being the less fit, more sun-starved version of Butch.

http://www.3ddmd.com/images/Messiah/BeerBelly.jpg

[Julez4001]

Nice pic Gary but i find Messiah lacking in the lighting bouncing inside look that it kinda need.
Its really hard to get that look, The translucency effect is powerful but it doesn't play nice wih basic shader.

[chikega]

We'll have to hook up Julian and geek out a bit, err, I mean, brainstorm. :D

[Julez4001]

No problem but my main focus is figuring out how to get the light to bounce inside the body accurately

[dobermunk]

Didn't Taron mention he was out to hook up the translucency channel?

Here's hoping...

At any rate, Chikega - that looks like a neat claymation style already. Me likes!
And I get that stuck-in-the-corner feel when you guys talk of getting together. Your last session bore the subsurface candle scene, right?
Last question: chikega, what render times do you have there with GI and I assume a decent AA level?

[chikega]

You're always welcome to Atlanta, home of the '96 Olympics, David! :) Actually, I'd love to visit Germany one day.

Render time for the above pic at 640 X 480 took about 5min 35sec. Specs: Adaptive SS AA X 3, Monte Carlo GI Samples 3, GI Depth 1, GI Noise Reduction (default). One Spot light.

On the object itself, there's the basic shader, with two layers of AoN shaders (fractal and turbulence), displacement is on but it's very subtle.

http://www.3ddmd.com/images/Messiah/BeerBelly1.jpg

[dobermunk]

The red clay of Georgia! I travelled through Atlanta once, selling posters at the university.
Great city!
As to your model, that's some serious cellulite there...
I find the times good, but not great. I suspect better looking fakes will be possible once the translucency channel is pluggable. Look forward to seeing what you guys come up with!

[tjnyc]

Nice work Gary, but the boy needs a tan.http://www.cgtalk.com/images/icons/icon12.gif

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