REDSPEC SSS

[Witpapier]

Steven Spielberg awesome stuff

[Witpapier]

maybe when I dont work myself to death ill have time for this and the hair.

[face_off]

I've had a chance to investigate SSS in Octane a little deeper and think my previous settings can be improved. In summary, I think you can use either the diffuse OR specular node for SSS - it doesn't particularly matter which. The settings I've come up with ....

Code: Select all

Kernel - PT, maxdepth = 6, rayepsilon = 0, caustic_blur = 1

Skin material = Material Mix
 - amount = 0.4 (ie. 40% of light coming from subsurface scattering, 60% from glossy)
 - material1 = diffuse
   - diffuse = 0 (black)
   - Transmission = 1 (white)
   - medium = scattering
     - absorption = 0, 256, 256 (so red is not absorbed and hits the back of the mesh)
     - scatter = 50, 0, 0 (so red is scatter back towards the light)
     - scattering_direction = 0
     - scale = 200 (or if the figure renders with a glowing nose, move to 300)
 - material 2 = glossy highlights setup of your choice

For material 2, if you need to lighten the figure's skin, reduce the gamma of the texturemap down from 2.2 to 1-2. For highlights, set the "index" to 1.44, filmwidth 0, and set the "specular" to a "mix" with "amount" = falloff map, texture1 = 60, 60, 60 and texture2 = 256, 256, 256. Roughness will be 0.3-0.8 depending on the skin oilines.

If the skin is rendering too red, reduce the redness by taking red of the the diffuse map on the glossy node (ie. don't touch the SSS node).

Paul

[Witpapier]

I've had a chance to investigate SSS in Octane a little deeper and think my previous settings can be improved. In summary, I think you can use either the diffuse OR specular node for SSS - it doesn't particularly matter which. The settings I've come up with ....

Code: Select all

Kernel - PT, maxdepth = 6, rayepsilon = 0, caustic_blur = 1

Skin material = Material Mix
 - amount = 0.4 (ie. 40% of light coming from subsurface scattering, 60% from glossy)
 - material1 = diffuse
   - diffuse = 0 (black)
   - Transmission = 1 (white)
   - medium = scattering
     - absorption = 0, 256, 256 (so red is not absorbed and hits the back of the mesh)
     - scatter = 50, 0, 0 (so red is scatter back towards the light)
     - scattering_direction = 0
     - scale = 200 (or if the figure renders with a glowing nose, move to 300)
 - material 2 = glossy highlights setup of your choice

For material 2, if you need to lighten the figure's skin, reduce the gamma of the texturemap down from 2.2 to 1-2. For highlights, set the "index" to 1.44, filmwidth 0, and set the "specular" to a "mix" with "amount" = falloff map, texture1 = 60, 60, 60 and texture2 = 256, 256, 256. Roughness will be 0.3-0.8 depending on the skin oilines.

If the skin is rendering too red, reduce the redness by taking red of the the diffuse map on the glossy node (ie. don't touch the SSS node).

Paul

Thanx Paul. I am slowly making progress with my diffuse skin. I really like it in conjunction with my Octanedefaults settings. If you look at my Blog http://redxart.tumblr.com/ you will see the results Im getting. I have not uploaded it yet for use, but it has got potential to be perfect. Im just working on some transparency maps and custom specular maps that can be used to give a more realistic look. If you want I can mail it to you, maybe can give some insight.

[Erick]

Interesting approach, Paul. Thanks for sharing.
I was just having a very brief play with it and it looked totally different from my other renders (of skin mat.) Can't wait now, to play more with it

One thing tho ... I was using your material on V4 and the eyebrows were really .. well .. they didn'T really look good, lol ... but that was expected, since it's a skin material after all.
I was trying to exclude the eyebrows with an opacity map.
The goal was to have the skin of the face rendered with you new material from above, but leaving out the eyebrows and have them applied with a simple diffuse or glossy material with the according texture/image map. But that didn't work out, at all haha ... Next time need to have another go at it =)

[face_off]

One thing tho ... I was using your material on V4 and the eyebrows were really .. well .. they didn'T really look good, lol ... but that was expected, since it's a skin material after all.
I was trying to exclude the eyebrows with an opacity map.

I think the thing missing from the shader is that you should load the diffuse texturemap into a "floatimage" and plug that into the transmission pin of the diffuse material. Then you will need to substantially reduce the scatter scale to get the SSS effect to show. But that will fix SSS appearing in dark areas.

Paul

[ch0pper]

Thanks for sharing the info is always Paul, is any chance you could upload poc file for us to play with I was find it better sometimes test specific purposes.

Thanks

[face_off]

I'm reluctant to provide actual materials, since they are probably heavily customized to my lighting and texturemaps and will look terrible for everyone else - but here you go! There is a BIG change in the next version of the plugin, in that RGBSpectrum colors will be transferred to Octane in "Linear color space" rather than "rgb color space". That change has confused me - not sure if the "scatter" red amount is pre or post the linear space change - so I'll need to confirm that later on. The change to linear space means the color you specify in a the color picker will be the actual color Octane uses (whereas previously is was tonally incorrect).

The only parameter you should be changing on "material1" is the "scale" - I originally used 300, but didn't have the diffuse mapped plugged into the transmission. Use you own glossy for "material2".

Paul

[Erick]

I had a little play over the weekend, with the material you posted, Paul. Thanks for sharing.
I really liked the results I was getting, even more so, after changing filmwidth to 1 (in the glossy part), but man did that change the whole appearance of the skin.
With setting filmwidth to 1, the whole appearance of the skin got much "bolder" looking. I tried to compensate it by either changing the diffuse value a bit, or by adjusting the 1st specular texture to a bit of a higher value (which initially was 60/60/60)
Quite the good toy to play with =)

[face_off]

Hi Erick

The next version of the plugin uses Linear Color Mapping (which corrects the current error where the plugin uses RGB color mapping) - so colors like 60/60/60 become much darker. So unfortunately the move to Linear Color space will mean so additional tweaking.

Regarding film width, someone made the comment that skin has no film, so this should be 0 (and the render output from 0 is pretty good). But I wonder in fact if skin /does/ have a film, so 1 may be the right value. The only thing that turned me off was that film width 1 gave a tinted color, which depended on the "index".

Paul