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Old 12-08-2013, 01:08 PM   #11
ysalex
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aren't they basically the same setting? From what I understand, I can use scatter radius as a map to achieve backscatter in certain places, and then tune the scale to the appropriate level.

I've tried going in increments of .25 from 0 up to 5, and never acheived anything like that fine line of scatter.

Are you perhaps adding your wrinkles into the scatter radius map to bolster the scattering in specific areas?

Maya vray.
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Old 12-08-2013, 10:00 PM   #12
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whats your prepass rate yuri ? very important parameter. if you set it high enough you can see that fine scattering even on pore level details (depends on your shader and lighting of course) . prepass rate of 2 looks usually very good, but its a pretty high setting so your renders will take quite some time to render. if your resolution is high enough though, you can get away with prepass rate of 1
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Old 12-08-2013, 11:10 PM   #13
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ysalex:
It is simply a lot of try & error to get the right effect.

Arnold and Vray have totally different shader concepts and settings.

A few tips:

First, you need very good quality maps that are large enough ( I prefer now 8K maps), otherwise your skin results will lack the 'real skin' look, no matter what your shader settings are.

Then, your model scale must be in real size.

For VrayforC4D:
The right SSS-Prepass rate-setting is crucial for the result. I use 0 in most cases.
I also never touch the SSS-scale setting as my model has already the right size, I leave it at 1.

From my long-year attempts, choosing the right scatter color along with the matching scatter radius and phase function is what produces all the magic in Vray.
I tried it for several years again and again, endlessly, until I found the right values for them. In the past, I also used complicated constructed scatter- weight maps and scatter-color maps etc, but you don't really need that for good results.
Especially the scatter-color is very important.
Only Vlado might know why, but the color-settings there do not only affect the color of the backscatter-effect, but also the total amount of the whole SSS-effect.
It is like juggling with 10 motor-saws. A slightly false set value there and all is gone.
Can really be veeeery frustrating, I assure you.

Also essential is the right specular-shading.
In Arnold, you can use the SSS and specs in one shader.
In Vray, it never produced satisfying results for me.
I think it's because Vray's SSS is not primarily designed for skin shading.
No matter what I tried, it always looked odd when I used the specs inside the SSS-shader (A note: VrayforC4D's VrayAdvanced-Material is different to the Vray-Max or -Maya versions)
So I do my specs in a separate shader.

Then choose 'Simple' for Single Scatter and 16 as Single scatter Subdivs, Prepass LOD is 4 and Prepass Blur is 1.2 .

I only use one or two color maps (in C4D we have a 'filter' that enables us to color-tweak, saturate etc. any basic color texture) and that's it.

Sounds simple, but took me a few years to fiddle that out.
Vray has too many settings that all has to match for getting it right.

Arnold is much easier to handle.
But it also needs some days to get the right settings (and I can tell, my settings are much different to the ones Lee has written in his Arnold-skin tutorial )

So, there is really no secret sauce, but both renderers need a lot of try & error to get the right skin look.

Again, without really good color maps, you will never get really good looking skin, no matter how right your settings are.

Last edited by RK-art; 13-08-2013 at 12:28 AM.
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Old 13-08-2013, 01:49 PM   #14
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Something else to keep in mind depending on the look you're going for... Movies and HD TV broadcasts rarely show natural looking people. Everyone is wearing a lot of make-up so the specularity/reflectivity is very low compared to real skin and SSS may act very strange as well. That's also because the lighting is pretty different from real world conditions, people are usually overlit because of the lenses or the sensitivity of the film stock or CCD.

I also know that we've been doing a LOT of photo shoots in the past few years, starting with the ME3 trailer and several departments are co-operating from textures through shading to comp, despite all the new raytracers and GI and what, so it's still not an easy to solve problem as far as I can see...
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Old 14-08-2013, 12:04 AM   #15
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Yes, that's right, make-up and film-look makes a totally different looking skin than pure skin under natural light conditions.
But you can mimic those effects either in the shader or later in post, depending on what you want/need to archieve.
I think, the first goal is always to produce a good looking natural skin with your character, from that you can easily add make-up-effects in the shader via the diffuse-channel or a specific film- or tv-look later in AE (MagicBullet does a great job).
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Old 15-08-2013, 04:57 AM   #16
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Here is an extreme Close-Up-Shot with Arnold.
I added a capillar-vessel texture in the subdermal layer.

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Old 14-10-2013, 09:58 AM   #17
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Cool test with Arnold Ralf, are you using the skin shader or the standard one?
cheers
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Old 15-10-2013, 12:52 AM   #18
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Thanks Pascal.

I use the Arnold Skin-SSS-Shader that Juanjo implemented in LWtoA.
I am really happy with the results so far, but I will further try to make it better.
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Old 30-10-2013, 03:50 AM   #19
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Really nice tests. I test Arnold SSS myself too. Coud you tell me what is the resolution of displace you used for last render? Do you use this method with "microbump", mentioned by bukkiit and Bigguns in other thread? May I ask you to show your refl and bump textures?
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Old 30-10-2013, 09:01 AM   #20
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looks very good indeed!
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