New Principled Hair Material added to FiberFx

Marianne using Principled Hair, courtesy of Mauro Corveloni

New to LightWave 2020 is a material called Principled Hair. It is a simplified shader based on the Principled BSDF limited settings. You will see that there are only five inputs compared to Hair's 19. Because hair can be considered a dielectric material, you will notice that is no diffuse control and that the Color doesn't just immediately make the hair assume the color you enter.

The Principled Hair material is designed for Stroke-based Fiber FX hair

  • Color - (Default: 47 13 0) The color chosen to tint the hair strand. If you want to force the color chosen, set Roughness and Radial Roughness to 100 %
  • Cutical Tilt - (Default: 3.0 °) Moves the highlight up and down the hair - typical human hair has a tilt of 3-7°
  • Roughness - (Default: 25 %) The roughness along the length of the strand, the amount of scattering of light falling on the strand
  • Radial Roughness - (Default: 75 %) The roughness around the strand
  • Index of Refraction - (Default: 1.55) Controls how the glints are placed

You might find you need to heavily increase your refraction samples for Principled Hair to not appear noisy. Rather than increasing Refraction samples everywhere in the render, use the new Refraction sample override in the Shading Model tab of the Surface editor to only increase refraction sampling for your hair surface