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Comment: wikit macro-replace (build 4280ad5-2021.10.08.115947) run by cwalker
Note

Do you need help rendering Xgen hair? Try this example file for Maya.

XgenExample.zip
Info

You can find an easier way to shade and control hair using a pattern included with RenderMan: PxrHairColor

 

 

PxrMarschner HairImage Modified
© Disney/Pixar

PxrMarschner is a material designed to render realistic hair, fur, and fibers.

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Carousel Image Slider
dotsfalse
sliderHeight400
labelsFiltermarschnerHairExample
gutterSize3

 

 

Diffuse Parameters

There are two choices of diffuse models: Zinke and Kajiya. By default, it is set to Zinke diffuse model which is for bidirectional scattering. See Importance Sampling for Physically-Based Hair Fiber Models.

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labelsFilterdiffusecolorexample
slidesToScroll2

Specular Parameters

The bulk of your controls can be found under the Specular Parameters. Each of these relates in some way to the description below.

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Note

The Specular Gain controls allow the artist to break energy conservation for artistic purposes. If the values entered add to greater than 1.0 then the hair is not energy conserving. This is only important if you are unsatisfied with the look (it's too "hot") or are interested in starting with physically realistic shading.

Info

The default gain for the below Specular parameters is 0.33, however, they can all be set to 1.0 and that is preferred as they are not additive. This default will change to 1.0 in a future releaseis now 1.0, previous versions may have been set to 0.33.

 

 

Primary Specular Gain

Gain for the R lobe of Marschner specular. This is like a clearcoat where the specular is fairly sharp and glossy and normally not colored. This specular is a direct reflection which is not tinted by any volume attenuation. Modifications of the R lobe help to make a hair look "wet" as well.

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dotsfalse
arrowsfalse
labelsFilterprimaryspecgain
slidesToScroll01
captionstrue

Secondary Specular Gain

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Gain for glints. This is a multiplier for the effect of Glints and operates like the other gain controls.


 

Anchor
primarySpecularColor
primarySpecularColor

Primary Specular Color

Specular color for tinting the Primary Specular (the R lobe). For natural hair and fur, this should always be white.


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dotsfalse
arrowsfalse
labelsFilterprimaryspeccolor
slidesToScroll4
captionstrue

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dotsfalse
infinitefalse
arrowsfalse
labelsFiltersecondaryconeangle
slidesToScroll01
slidesToShow4
captionstrue

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This is the cross-section aspect ratio of the hair and is usually between 0.85 and 1.0 for realistic hair. This is most often used when rendering curly hair. (Note this depends on the hair normals.)

 

Glow

Glow can be used to create hair fibers that appear to emit light or "glow" in the scene. 

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Carousel Image Slider
dotsfalse
infinitefalse
arrowsfalse
labelsFilterglowcolor
slidesToShow4


Globals

This section provides global controls for the entire material. Presence is also a global parameter that will mask out or "cutout" all the lobes as-if the object isn't present where the mask has a value of 0.0

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Expand
titleNamed Lobes

Below are the named and user lobes from PxrMarschnerHair.

Named Diffuse Lobe

  • HairDiffuse

Named Specular Lobes

  • HairSpecularR
  • HairSpecularTT
  • HairSpecularTRT
  • HairSpecularGLINTS

User Lobes

  • HairAlbedo
  • HairTangent
  • Position

 

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