...
Color |
|---|
Melanin
This parameter, alongside the along width the Melanin Redness bellow, controls the generation of natural-looking hair colors. It sets the amount of melanin in each hair strand. Colors will range from white at around 0 , to blonde at around 0.2 to red and brown around 0.5 and to black at the maximum value of 1.0.
...
Controls the redness of hair. In more technical terms, this controls the the proportion proportion of red pheomelanin (as found in red hair) relative to the amount of eumelanin.
...
It is sometimes desirable to render non-natural looking colors for hair. Using a dye color allows setting the color directly, without using the melanin parameters. The dye weight allows mixing both methods using a simple mix. Setting tthe the Dye Weight to 1 will use only Dye Color and setting it to 0 will only use Melanin and Melanin Red, all . All values in between will use a mix of both.
...
Natural looking hair requires a slightly different parametrisation variations from one hair strand to the next (having totally uniform parametrisation over the entire hair clump is generally only possible for synthetic hairs). The values in this section allow to randomly vary most parameters by a certain amount. Not Note that the variation is coherent from frame to frame in animation. A value of 0 indicates no variation for the parameter, a value of 1 indicates the largest possible variation and will be closer to a totally random value.
...
An interesting aspect of hair rendering is that all the intricate visual details seen in hair stem from the scattering of light in a multitude of hair strands and is not due to the complexity of the BRDF on a single hair strand. This seemingly simple observation explains why so many complex shaders are not successful at conveying a realistic look for hair. This includes the widely used shaders based on the Marschner model not using volume scattering. The Our shader simulates 3 scattering events from one single hair strand and then proceeds with a Monte-Carlo simulation to follow light paths inside the hair volume.
...