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3Delight Surface and Lighting Thread
Posted: 03 May 2013 07:45 PM   [ Ignore ]   [ # 16 ]
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wancow - 03 May 2013 07:41 PM

Yes they would… What I could do, I suppose, is make a negative for the diffuse and apply that map, that should balance it out…

make a negative for the diffuse and apply that map… where?

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Posted: 03 May 2013 07:51 PM   [ Ignore ]   [ # 17 ]
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diffuse strength.  I’m using the lana Spec maps for Samantha

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Posted: 03 May 2013 07:51 PM   [ Ignore ]   [ # 18 ]
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wancow - 03 May 2013 02:30 PM

30% Diffuse - 70% SSS.”

Why would you have SSS that strong? (I’m not saying this is wrong, I just don’t understand. Most formulas seem to reverse that proportion, in general.)

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Posted: 03 May 2013 07:53 PM   [ Ignore ]   [ # 19 ]
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VWrangler, I’m told SSS should be as high as 90 and Diffuse as low as 10 percent… because skin is transparent down many, many layers.

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Posted: 03 May 2013 07:57 PM   [ Ignore ]   [ # 20 ]
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Throw the percentages out the window, boys! The shaders are not designed to incorporate conservation of energy! Keep the diffuse down out of 100%, and don’t overdo the SSS.  Use both specular channels, you need them.  And don’t forget bump, which I neglected to post.  If you really want conservation of energy you NEED to analyse each ray and have it react based on what happens: refl = spec/diffuse, absorption = diffuse/sss.  You are not going to get the “correct” results just by altering percentages, so you have to wing it!

Last render for now.  Fixed his nails, tweaked the eyes but really didn’t get what I wanted because of the light angles which I changed… tweaked the lights down.  I know he’s semi-floating there, but to hell with it.

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Posted: 03 May 2013 07:59 PM   [ Ignore ]   [ # 21 ]
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sorry??
so we would leave diffue color alone and then in the next slider apply the negative of the diffuse to the strength slider?

never would have thought of these things but will try them

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Posted: 03 May 2013 08:02 PM   [ Ignore ]   [ # 22 ]
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wancow - 03 May 2013 07:53 PM

VWrangler, I’m told SSS should be as high as 90 and Diffuse as low as 10 percent… because skin is transparent down many, many layers.

Here’s the problem with trying to be physically accurate: the shader’s aren’t designed for it.  If you read the HSS doc, scant though it is, it notes that SSS is affected by diffuse strength and further it is affected by a diffuse map.  How it is affected is not stated.

You are also going to lose all that glorious detail in the diffuse map if you reduce the diffuse too far, because the SSS channel does not seem to carry it through even if you put the diffuse map there.

The other problem we have here is that the SSS implementation that we are using is unique.  Its NOT the 3Delight implementation, its omnifreaker’s version of it.  US2 is closer to the actual 3Delight one, but if you really want 3Delight’s you’re going to have to build your own skin shader and incorporate it.  Good luck, I’ve tried and I still can’t make sense of what is happening with it.  Not to say you won’t have better luck than me!

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Posted: 03 May 2013 08:03 PM   [ Ignore ]   [ # 23 ]
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wancow - 03 May 2013 07:53 PM

VWrangler, I’m told SSS should be as high as 90 and Diffuse as low as 10 percent… because skin is transparent down many, many layers.

... but skin isn’t transparent down many layers. It can’t be; if it were, people would be much MUCH redder than they are.

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Posted: 03 May 2013 08:07 PM   [ Ignore ]   [ # 24 ]
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vwrangler - 03 May 2013 08:03 PM
wancow - 03 May 2013 07:53 PM

VWrangler, I’m told SSS should be as high as 90 and Diffuse as low as 10 percent… because skin is transparent down many, many layers.

... but skin isn’t transparent down many layers. It can’t be; if it were, people would be much MUCH redder than they are.

Its not transparent, its translucent.  Light penetrates, but not all light.  Some is reflected, which we try to accommodate for with our specular and diffuse channels (yes, diffuse is REFLECTED light) and some penetrates the outer layers of oil and skin, bounces around and then exits again at a different point.

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Posted: 03 May 2013 08:20 PM   [ Ignore ]   [ # 25 ]
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evilded777 - 03 May 2013 08:07 PM
vwrangler - 03 May 2013 08:03 PM
wancow - 03 May 2013 07:53 PM

VWrangler, I’m told SSS should be as high as 90 and Diffuse as low as 10 percent… because skin is transparent down many, many layers.

... but skin isn’t transparent down many layers. It can’t be; if it were, people would be much MUCH redder than they are.

Its not transparent, its translucent.  Light penetrates, but not all light.  Some is reflected, which we try to accommodate for with our specular and diffuse channels (yes, diffuse is REFLECTED light) and some penetrates the outer layers of oil and skin, bounces around and then exits again at a different point.


Right, reflection and refraction. The vast majority of light is actually reflected off or absorbed by skin and its melanin. So subsurface would be an undertone, not the dominant.

For what it’s worth, if I’m understanding the 3Delight documentation correctly (3Delight’s own manual, not anything from DAZ), the most accurate computation of subsurface would come from point cloud occlusion, one of the options in what Studio calls “Scripted 3Delight”. Now, I actually really love 3Delight’s point cloud occlusion ... but if you’re trying to get to something resembling the images posted earlier in this thread, I can promise you that point-cloud will be deeply disappointing.

When I use point-cloud occlusion render, it’s because it gives a slightly cartoonic look without being a cartoon shader. (That image is entirely worksafe, oddly enough.) That image isn’t properly lit—the trick with point-cloud is that it also places its own unseen light source into the image to provide the occlusion light, which is tricky to compensate for, so it’s kind of blown out, but you can get an idea what point cloud does. Also, I believe that both of those characters have US2 applied, so they’ll have both subsurface and translucency active, as well as both diffuse and specular channels.

(EDITED for clarity.)

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Posted: 03 May 2013 08:51 PM   [ Ignore ]   [ # 26 ]
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Which images above, vwrangler?

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Posted: 03 May 2013 08:55 PM   [ Ignore ]   [ # 27 ]
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All of these examples seem a bit too glossy for me. Has Mike just been working out? wink

I know there should be some secularity on the skin, but it seems a bit high to me in these images. (Maybe it’s the lighting.)

On another note, I’ve been thinking about procedural skin shaders, and particularly non-human skin. Are there any procedural tricks that are commonly used to get the sort of pigmentation variation usually found on palms and soles?

Edited to add: SSS gets tinted by blood color, yes? So if I want my aliens to have non-hemoglobin blood, I might use a different color? Do you folks recommend tinting diffuse with the chromatic opposite of the blood color? I think that would need to factor into the percentages, as well, because any tinting is going to cut down the brightness of that channel.

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Posted: 03 May 2013 09:09 PM   [ Ignore ]   [ # 28 ]
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zigraphix - 03 May 2013 08:55 PM

All of these examples seem a bit too glossy for me. Has Mike just been working out? wink

I know there should be some secularity on the skin, but it seems a bit high to me in these images. (Maybe it’s the lighting.)

On another note, I’ve been thinking about procedural skin shaders, and particularly non-human skin. Are there any procedural tricks that are commonly used to get the sort of pigmentation variation usually found on palms and soles?

Edited to add: SSS gets tinted by blood color, yes? So if I want my aliens to have non-hemoglobin blood, I might use a different color? Do you folks recommend tinting diffuse with the chromatic opposite of the blood color? I think that would need to factor into the percentages, as well, because any tinting is going to cut down the brightness of that channel.

Yes, David’s a little sweaty.  I could tone down the specular a bit, but I like it that way.

Yes you can tint your SSS color to suggest different colors underneath.  Over in the superhero render thread, I had lots of fun doing my Hulk render with lots of green SSS.  Tinting the diffuse is an old standard, I don’t put much stock in it anymore myself but people I respect do it quite a bit still.

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Posted: 03 May 2013 09:17 PM   [ Ignore ]   [ # 29 ]
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evilded777 - 03 May 2013 08:51 PM

Which images above, vwrangler?

Any of the ones earlier in this thread. Sorry, wasn’t clear on that. Point-cloud occlusion isn’t going to get anything resembling those images without a LOT of tinkering with settings. Which settings, whether Ubersurface or 3Delight render—and there’s an entirely different panel of settings to work with point-cloud—I have no idea.

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Posted: 03 May 2013 09:21 PM   [ Ignore ]   [ # 30 ]
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well, they are all mine except for the first one.  And I posted my settings, or close to them.  They are pretty basic, with a little HSS and a little UE, you can get some darn nice skin.

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