hack for better EZSkin SSS Skin

  • I've been thinking about this for a few days now and finally tested it out and it works. The problem I was having was that places on a figure's skin where there was dark makeup were not getting the same shine or SSS as the rest of the skin. The issue is the red filter in the shader setup. The red filter is there to keep things like eyebrows and facial hair from receiving the same SSS as the rest of the skin. The problem is that eye makeup is often not red and will be excluded from the SSS. The solution is to plug your natural, un-made-up face maps into the red filter and leave your maps with makeup for the rest of the shader. I suspect this would also be very useful for tattoos on the skin. Image on the left is the normal setup and image on the right uses the natural un-made-up face map plugged into the red filter.
    0_1525543553598_better skin 1.jpg

    Here is the setup for that:
    0_1525543595268_skin hack 1.jpg

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    @ghostship Thank you for this. The lips are fabulous. Love the shader.

  • @Ladonna This is @bopperthijs shader for EZSkin3. All I did was plug the natural face map into the red filter.

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    @ghostship Have to do this too. Thank you for this great tip.

  • nice solution

  • @ghostship ummm, isn't dark makeup an additional, optically opaque layer on the surface of the skin which will absorb any sub-surface scattered light as well as reduce the inbound, pre-sub-surface-scattered light in that area. I ask from some ignorance on the matter, having a daily facial care routine that varies between wire brush and Dettol, to vigorous scraping with half a broken brick. That said though, my original point about kohl, and the light absorbing properties of pulverised carbon still apply. Will there still be significant, visible SSS effects on such darkly made-up skin?

    Your renders are excellent, as always, but it really looks like the hue and brightness of the eyeshadow has markedly changed on the right-hand image. Or is it your assertion that the RHS is truer to the original makeup texture?

    Your point about tattoos is very well made, as being subcutaneous, they will certainly be affected by SSS.

  • @anomalaus you are right about the dark makeup and SSS but that is already controlled by the texture map anyway. The effect as seen in @ghostship’s render has nothing to do with SSS. The red filtered map is connected to the blur input of the SSS shader and it just does what it says: blurring the map;) If you want to add additional control of the SSS amount you have to modulate the scale input of the SSS node.
    Anyway the difference in the renders comes solely from the gloss nodes and how they are mixed with the diffuse in this shader setup.

  • @anomalaus Yes, the eye makeup on the right is as it should be and that is with my fix. The red filter affects the gloss of the skin and if your map has black on it or colors other than red there will be less or no gloss in those areas on the render.

  • Now that's an great idea! I will see if I can implement that in the next EZcycles update.

  • @ghostship & @nagra_00_ I'm responding again only to clarify my own understanding. I agree that if the skin map is providing colouration for skin, exclusively, such as variations in melanin and natural skin pigmentation, then just choosing a darker colour should not affect the modulation of SSS, as a less red texture map would inappropriately do (I'm assuming that melanin levels should have no impact on on the levels of SSS, whether that's correct or not. I am not certain). In the case where light absorbing pigments are layered on top of the skin, I would have thought that their blocking of both the directly diffused (scattered reflection) and transmitted SSS back to the camera would be identical, and therefore appropriately reduce SSS in that area, since it's not actual skin that the camera sees there, but makeup (with appropriate graduation of effect as the makeup becomes less opaque). In the case of a blurred input, I would still assume it appropriate to include the made-up area as a valid input for the overall SSS. I understand that a surface layer doesn't impact the sub-surface scattering of what light already gets that deep, but the effect of SSS must still be transmitted back through any surface layers to be visible to the camera.

    Maybe I'm just assuming that kohl and other dark eyeliners should be less glossy than the skin they overlay, and that is not actually the case. If so, I'll stand corrected and say no more. :-) Always happy to learn something new (to me, at least).

  • @anomalaus yes he color of the texture map has an impact on the amount of SSS calculated by the node. White gives highest SSS and black no SSS because all light is already absorbed by the surface. So i am in sync with your assumption about the impact of makeup on the amount of SSS.

    I made a small test render and the result is as expected :)