Vray Skin 2 - Tips

[MikeN]

Thought I would post up some Vraysss2 tips, along with anyone else willing to share.

I will just explain my own "Artistic" understanding of what the parameters do.

Prepass rate - Increases quality of sub-surface scattering. Leave at -1-0 for tweaking and 0-2 depending on final render size.

Scale - Leave at around 1 If using real world scale.

Overall color -
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Diffuse amount - Will apply a diffuse value overwriting your sss effects based on how much your diffuse value is set to. Useful for makeup/hair.

Sub Surface color - Linked to your SSS Col.

SSS Col -
Example:
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Scatter Color - The more you darken, the less apparent your sss effects will be. You can also use it with a texture map like the example below.
Example:
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Trace Reflections - Turn it on for some nice reflections. It will slow down render times.

Single Scatter - Change it to simple and leave the rest on default, apart from other settings I will list below.

Front Lighting - Leave it on. This enables your front sss scattering.

Back Lighting - This will slow down your render times a little. All it does is add that nice sss glow effects in the ears and fingers. Usually leave it off if you are not tweaking your back scattering.

Scatter Gi - This one is a killer to your render times. Only turn it on for final renders.

Whenever I have it off, I will also turn off indirect illumination/GI environment. Leaving indirect illumination on will tell it to bounce light just off the top surfaces of your skin instead of absorbing the light like real skin does. I may be wrong tho :/


Now onto a little more confusing area.
Since vraysss2 is lacking in good reflections and Spec controls you need to use it along with Shellac material.
So all that means is you are blending vray sss effects with a diffuse material to leach the extra reflection controls from.
You need to insert VrayMtl into your Shellac material slot and set your diffuse to black and apply your spec map.

My results may not be as good as others, but hopefully it will help people to get started with using it.
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Feel free to post your tips or crit any of the above info.

3Dsmax mat attached below.

[adamlewis]

Thanks for the tips, Mike. With regards to VRayBlendMtl, have you experimented with the additive shellac mode? As the name of the setting implies, instead of blending the materials in the node together, it will add the coat layers on top of the base. This has the advantage of allowing you to derive the reflections from the VRayMtl while omitting other properties such as the diffuse coloring. From my limited experiments with it it seems to work fine, but I am relatively new to Vray so I may be missing something.

[MikeN]

Double Post

[MikeN]

Hey Adam

Your right, I've been looking for something like this,thanks alot :thumbsup:

[Manuel Poehlau]

Nice tests Mike. The sss seems a little bit strong.
I think it´s a good idea to start a vray skin thread,since there is not so much info about it out there.
I also use the shellac mode to blend the vraymatl reflection with the sss2 shader, seems to work fine. For a clean skin ( i mean,no dirt,no make up,no hair etc) I don´t want to have any diffuse value mixed in.
Looking forward to see more results :thumbsup:

[collings]

cool Mike thanks for sharing :)

[MikeN]

Cheers guys,
I've updated the above info/shader to work a little better.

[tiktok]

wow! awesome. thanks for the tips! your results look fantastic. going to try to port this over to vray for maya ;P

[Ganjica]

Great idea! I spent the whole day yesterday to tweak the specular with sss2, and at the end I made a 2nd light rig just for the specular since I was not happy with the results. I thought it was just me having troubles with lack of settings for the specular and reflections.
Using the shellac is a way more powerful and ant time saving!!

[Ganjica]

One more thing I noticed but I don't know if coming just form my wrrng settings, is that GI seems to kill a good amount of the scatter effect. Do you guys use GI when you render with vray?

[adamlewis]

Ganjica, if you're using GI make sure you turn on "Scatter GI" in the VraySSS2 properties (at least for final renders; the setting is very expensive). Without that setting on, indirect rays will be treated as if they were hitting a plain old diffuse surface. I'd also recommend turning off or at least severely limiting the "Generate GI" setting under object properties, as it creates a rather undesirable look with SSS materials under most circumstances.

[Ganjica]

AAAaaaaaarrrrggghhhh! That's why every time I was tweaking the settings without the GI the shader was looking good, and then it was going to act as a normal blinn shader, now i got it! Thanks a milllllion!!