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Silent Eli ~ layered skin test

Posted: Mon Apr 02, 2012 5:31 am
by elwisoroarke
Just a simple custom skin shader macro test to get a nice layered effect in surface sebum spread & breakdown, epidermal & subdermal response, scatter & overall luminance of human skin. The blood map helps give the feel of a bit of light reflecting back out of the skin as it should without the infamous translucent "rubber/wax" SSS look that comes without depth control. The normals are providing a nice breakdown of the glossy oil layer, but they probably could be dialed down a tiny bit. Lit with a softbox as key light and another mesh light for a bit of fill.

Re: Silent Eli ~ layered skin test

Posted: Mon Apr 02, 2012 7:30 am
by tehfailsafe
Phenomenal!
Though the ear looks a bit off, perhaps it's just a result of the depth of field...

Plan on sharing more of those settings and bloodmap image? I'd love to see more on how you got to this!

Re: Silent Eli ~ layered skin test

Posted: Mon Apr 02, 2012 5:39 pm
by harford
A good start, few things to hekp

Texture looks too saturated
so much is baked into the texture, it's hard to tell if the render is actually any good at all, or the texture is doing most of the work.
the ear looks too clean and hard, like cg. Not soft.
You can see in the lips the bump map creating a look of dryness, where there is basically no SSS giving the lips that soft look. While you shouldn't use heavy sss on all parts of the head, it's important to retain that slightly translucent feel that makes skin look like skin, especially on the lips and eyes bags/lids, where skin is really thin.
Bump may be too strong, but this is a combination with the SSS to get right.
Nostrils.. don't know whats happening here, they are a black circle, there is no gradation of shade and the inner parts are not modeled.

Re: Silent Eli ~ layered skin test

Posted: Mon Apr 02, 2012 8:45 pm
by elwisoroarke
harford wrote:A good start, few things to hekp

Texture looks too saturated
so much is baked into the texture, it's hard to tell if the render is actually any good at all, or the texture is doing most of the work.
the ear looks too clean and hard, like cg. Not soft.
You can see in the lips the bump map creating a look of dryness, where there is basically no SSS giving the lips that soft look. While you shouldn't use heavy sss on all parts of the head, it's important to retain that slightly translucent feel that makes skin look like skin, especially on the lips and eyes bags/lids, where skin is really thin.
Bump may be too strong, but this is a combination with the SSS to get right.
Nostrils.. don't know whats happening here, they are a black circle, there is no gradation of shade and the inner parts are not modeled.
Thanks for the observations. This model test is built from a commercial texture & morph designed by our own MEC4D for the "Michael4" figure by DAZ3D. A lot of the realism is coming from the texture maps themselves, textured in DeepPaint3D, as well as the custom sculpt in zBrush. Both based off of photographic reference (not just photos slapped on a mesh set to it's default form). This is done in a number of the higher end textures available in the DAZ/Poser community to give a more consistent, "realistic" result across the variety of targeted biased rendering systems, (based on Renderman & 3Delight but with various limits) & range of user experience within the Poser & DAZ3D communities. MEC4D's texture, morph & map work is among the best out there, but given the shift into accurate full spectrum light & physically based materials, the way textures are built has begun to shift to fit the unbiased world better. You will see the result of her "reinvention" soon, which included things like actual 3D facial, head & body hair, not painted or trans mapped, to aid in the pursuit of realism. :) I am also a longtime advocate of photo realism in CGI, so many of my efforts, commercially & artistically fall in line with her standards and the unbiased rendering approach. Ideally a simple true diffuse color map, proper bump/normals, and specular control map, along with the right layered mix will give a lifelike photo realistic result, without baked in photo elements.

As to the model itself, yes the M4 (Michael 4) ears are still a bit "doll like" & would benefit from more detailed sculpting to mimic not only softness but contribute to "thickness" in combination with the right density map for control of the scattering. There is some ruddiness on the ridges of the ears in the color map itself, as it was on the actual human model, as likely left there to aid systems with more limited translucence & true SSS. Same issue with the lips, there is nice shine from the surface reflection, but some of the softer "juicyness" is hidden by the diffuse map...a thickness/density map vs the blood map I created would probably work better to control translucence in this material zone, along with a little more back scattering. The nostrils are actually painted black on the color maps, which unfortunately hides some of the actual modeling of the nostril (another "trick" to get around some of the issues the target biased render engines have had with modeled nostrils i.e. glowing due to lack of accurate AO etc...)

I love that we can now begin to build our models & textures based on how their physical world counterparts actually work, something both MEC4D & myself have long worked at... This was a test to see how with some simple setup, Octane handled the "Old World' way of doing things, and overall I'm pleased with the result, small but important details not withstanding. I think we'll all help push the organic "Human" side of GPU & unbiased rendering to places rarely has seen before in the virtual CG world.