Blur - The blurriness of the reflection. It defines
how widely the reflection rays spread, in degrees.
(0 = perfect mirror, 90 = diffuse shading)
Samples - The number of samples used to calculate the
reflection: the higher the blur value (the more the reflection rays
diverge) the more samples you need to achieve smooth results, without
unwanted noise. In general samples between 4 and 64 work for most cases.
If blur is 0 than automatically only one sample is used.
Anisotropic Strength – Defines how strong the
anisotropic effect will be: 0 is perfectly isotropic and a value of
1 makes the reflection blur only in the U direction. You must have exact
mapping coordinates for this effect to work.
Anisotropic Angle – Rotates the direction of
the anisotropic effect. When its 0 the reflection blurs in the U direction,
at 90 it blurs in the V direction. There is no point of using values
above 180, since the effect is symmetrical. (180=0, 200 = 20 …)
Normalize Angle for Texturing – Normalizes the
Anisotropic Angle into the 0-1 range, instead of degrees. This makes
texturing the parameter much easier.
Blurred Raytrace Depth - Defines the reflection “depth”
that still computes soft reflections. Usually you don't want to have
soft reflections reflecting softly (that is raytrace depth 2) on another
surface. :) Raising it over 1 can seriously kill rendering time.
Max Raytrace Distance - The maximum distance where
raytrace calculations take place. If the reflection ray does not hit
any objects while travelling to this distance it will automatically
sample the environment image instead (if there is any). It can seriously
speed up rendering and eliminate some sampling artifacts when used in
Raytrace Distance Falloff – This value is added
to the Maximum Distance and creates a soft transition between raytrace
and environment reflections. It eliminates hard clipping of reflections
on the objects.
(Max Distance and Falloff only works with Mental Ray 3.2 and above.
That equals Maya 5 and above.)
Color Gain - Modifies the reflection's color and
Saturation – De-saturates the reflection. (Most
materials in real life doesn't reflect fully saturated.)
Fresnel - A switch that enables angle-based, physically
plausible reflection values, based on Fresnel's equations.
Fresnel Strength - The intensity of the fresnel effect.
(0 is like turning the fresnel effect off, 1 is fully fresnel based.
This setting is not physically correct but makes slight modifications
IOR - The index of refraction that is used to calculate
the fresnel value.
Enable Bump - If bump is enabled than the reflection
can be mapped with a bump-like texture that effects only the reflections.
It can be used to roughen up reflections or produce nice glass window-like
distortions, without changing the base shader’s lighting.
Surface Bump - This is the channel that can be mapped
with a texture, if reflection bump is enabled. (basically like Maya's
Surface Bump Height - This value scales the effect
of the mapped texture. (like Maya's Bump Depth)