How you set up hair shading depends on the hair output you selected (see nHair Output) and what renderer you plan to use. If you output to curves, then you can use the hair color attributes in both the hair system and follicle nodes, but if you output to Paint Effects and are rendering in the Maya Software renderer, you can also use the Multi Streak attributes in the hairSystemShape. If you converted the Paint Effects strokes to polygons, you can also shade using the default tube shader that’s created upon conversion.
In order for Paint Effects Hair to have directional light for itself, you must assign a Paint Effects brush to the hair, then turn off the brush's Real Lights attribute and set the Light Direction.
To set up hair shading
In the hair system’s Attribute Editor, there is a Shading section for the hair with the following attributes: Hair Color, Hair Color Scale, Translucence, Specular Color, Specular Power, Cast Shadows, as well as Color Randomization. Setting these attributes controls how the entire hair system’s shading looks and renders.
If your hair output includes Paint Effects, then you can further shade using Multi Streaks. These shading attributes only appear when the scene is rendered.
Each follicle has shading attributes that can override or blend with the hair system’s attributes. In the follicle’s Attribute Editor, go to the Per Follicle Overrides section, and then go to the Render Overrides section where the follicle shading attributes are located: Color Blend and Color. The Color Blend value is 0 by default, meaning only the hair system color value is respected. If you set a Color Blend value greater than 0, the follicle color will be blended with the hair system’s color as a percentage. For example, a value of 0.1 would mean the follicle color would be blended at 10% with the hair system color.
If you convert your Paint Effects hair system to polygons, then a default Paint Effects tube shader is created. The former color attributes you set in the hair system are converted to the tube shader, but there is no construction history for these attributes. Any shading changes you want to make after you convert Paint Effects to polygons must be done using the tube shader. For descriptions of the attributes in the tube shader, see hairTubeShader.