Image from Piper ©

This pattern allows artists to create realistic and art directed hair and feathers that are easy to manipulate. Everything from human auburn hair to fantastical alien feathers are possible with just a few controls.

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Hair Color

Physical Mode

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Melanin

The melanin concentration in the hair fibers, from 0.0 to 1.0. Zero creates white hair and higher values create darker colors. For lighter hair you may need more Diffuse Gain in the PxrMarschnerHair material. Darker hair can use reduced values or even 0.0 for the darkest shades.

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Color Randomize

Using an RGB color or selected pattern, you can supply a random color to mix into the color chosen above.

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Darken Roots

Progressively darken the fiber's root by progressively adding more melanin. The value corresponds the additional amount of melanin at the root. The gradient can be shaped using Darken Slope and Darken End Position, below we darken the whole hair with Darken End Position set to 1.0.

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Randomize the melanin level of stray hairs, if hairIndexPrimvar is defined. 

Artistic Mode

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Stray Color

This allows you to choose an arbitrary RGB color or pattern for the stray colors. Below the Color is white with the stray hair colored with a solid color or a ramp. Stray Density is set to 0.5

Stray Random Color

This allows you to choose an arbitrary RGB color or pattern for randomizing and combining stray colors. Below the colors are set to black/none, dark red, red. The hair color is selected at blue. Stray Density is set to 0.5

Dye Color

Dye

Hair can be dyed with a color. This color will be combined with hair color in a plausible way. In the first example, the hair is very dark because a deep blue dye on red hair results in this color. A purer saturated color or a color chosen on hair with melanin set to 0.0 will have a more vibrant color like the red example.

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Here is a list of known primvars:

Random Pivot

Offset the random values to allow you to create centered, additive or subtractive random variations.

Random Seed

A global random seed to make sure you get different random results. Especially useful if you have duplicate grooms but need different coloring through random parameters.

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