9

540 Chapter 8: Modifiers
Note:
You can adjust the shadow characteristics by
changing the Hair Light Attr rollout (page 2–1351)
settings for lights that i lluminate t he hair.
Geom. Shadow—The amount of shadow
contribution hair receives from geometry in the
scene. Default=100.0. Range=0.0 to 100.0.
Geom.Mat.ID—The m aterial ID assigned to
geometry-r endered hair.Default=1.
mr Pa r a meter s R ol lout (H ai r a nd
Fu r)
Select an object with the Hair And Fur modifier applied. >
Modify panel > mr Parameters rollout
Lets you assig n a mental ray shader (page 2–1710)
to generate hair. 3ds Max passes the object’s UV
coordinate data, including map channels, to the
mental ray shader; strictly speaking, the shader
generateshairfromthisUVandmappingdata,
not f rom t he object geometry itself. (Multiple map
channels are supported.)
When you use a mental ray sh ader for hair, you
must render your scene using the me ntal ray
renderer (page 3–78) and set the Hair And Fur
render effect (page 3–220) method to “mr prim”.
Impor tant: When you assign a mental ray shader, only
the shader’s own controls apply to the generated hair.
All other Hair And Fur settings are disregarded.
Aside from the “mr prim ” option that you can
choose as a render effect (see Hair and Fur Render
Effec t (page 3–220)), no mental ray hair shaders
are provided with 3ds Max. This feature is meant
to support third-party hair shader products or
custom-coded hair shaders.
Interfa ce
Apply mr Sha der—When on, lets you apply a
mental ray shader to generate hair .
[shader button]—Enabledonlywhen“Applymr
Shader” is on. Click to display a Material/Map
Browser (page 2–1412) and assign the shader.
When no shader is assigned, this button is labeled
“None”. When a shader is assigned, the button’s
label shows the shader’s name.
Frizz Parameters Rollout (Hair and
Fu r)
Select an object with the Hair And Fur modifier applied. >
Modify panel > Frizz Parameters rollout
Frizz displacement is accomplished by doing a
Perlin noise lookup at the hair’s rest position
root, and then displacing the hair much the way
bump mapping displaces a surface normal. The
frequency of the noise function is set by the Frizz
X/Y/Z Frequency parameters. The mag nitude of
the displacement is controlled with Frizz Root and
Frizz Tip. If you set dynamics mode (page 1–547)
to Live, the viewports show the effects of changing
these settings in real time.