I tried doing what he said and, for me, diffuse materials don't change when I use transmission and medium settings. Is he using a different version of Octane, perhaps?We chose to use a material with subsurface scattering because it can add a sense of life to objects. First, create a new Octane Diffuse material, and choose a base colour in the Diffuse tab. Next go to the Transmission tab, and add an Octane RGBSpectrum texture to the Texture channel. Choose the colour you would like to transmit once light goes through the particle. Finally, in the Medium tab, add a Scattering Medium texture to the texture channel. This will give you absorption and scattering textures. Most times, you can leave Absorption at 0 and Scattering at 0.5. The scale slider is what controls how easily light can be absorbed and transmitted through the object – or in this case, the particles. We’ve used 1.75.
Now, it's my understanding that SSS is normally done with the medium tab of specular materials, sometimes as part of a mix material. But mixed specular/diffuse materials don't look as smooth for me as they do in Joey's example. At small scales (where the SSS has the most effect) they are grainy. At larger scales, the SSS is imperceptible. The scale/density slider seems very all-or-nothing at both scales, and the sliders for phase and for float texture don't do much at all.
Joey also fails to mention what textures go in which slots. I've seen Float Texture in Absorption, blank Scattering, and RGB Spectrum in Emission. This seems only to darken the center. I've also seen RGB Spectrum in Absorption, Float in Scattering, and blank Emission. This has a similar effect. (See attached. Transmission's effect seems simple, so I've ignored it in both.) What's going on here?
Some questions:
- Are specular materials the only or best way to do SSS?
- At what scale do SSS effects occur? (is it more like .001 cm or 100cm?)
- What is the best way to get that translucent, plastic-y look without grain or glassy shine?
