9

Falloff Map 1671
Procedure
To control opacity using a Fa lloff map:
1.
Assign the Falloff map as an opacity map.
2. Render to see the effect.
3. Adjust the falloff parameters to vary the effect.
Inter face
Falloff Parameters rollout
Fr o n t : Sid e —By default, "Front : Side" is the name
of the group at the top of this rollout. Front : Side
indicates Perpendicular/Parallel falloff. This name
changes depending on the falloff type selected.
In all cases, the name on the left refers to the top
set of controls, and the name on the ri ght to the
bottom set.
The controls are as follows:
• Click the color swatches to assign colors.
• Use the numeric fields and spinners to adjust
therelativestrengthofthecolors.
• Click the buttons marked None to assign maps.
• Turnonthecheckboxestoactivatethemaps;
otherwise the colors are used. These are on by
default.
•
Click Swap Colors/Maps (the cur ved
arrow) to exchange the assignments.
Fa lloff Type—Chooses the kind of falloff. Five
options are available:
•
Perpendicular /Parallel—Sets the angular
falloff ranges between face norma ls that are
perpendicular to the falloff direction and
normals that are parallel to the falloff direction.
Thefalloffrangeisbasedona90-degreechange
in face normal direction. (Default.)
•
Towards/Away—Sets the angular falloff ranges
between face norma ls that face toward (parallel
to) the falloff direction and normals that face
away from the falloff direction. The falloff
range is based on a 180-deg ree change in face
normal direction.
•
Fr esne l —Based on adjustments to the Index of
Refraction (IOR). Results in dim reflections on
surfaces facing the view, with much brighter
reflections on angled faces, creating highlights
like those on the sides of a glass.
•
Shadow/Light—Adjusts between two
subtextures based on how much light is falling
on the object.
•
Distance B lend—Adjusts between two
subtextures based on Near Distance and Far
Distance values. Uses i nclude reducing aliasing
on large terrain objects and cont rolling the
shading in non-photorealistic environments.
Fa lloff Direction—Chooses the direction of falloff.
Five options are available:
•
V i ewing D irecti on (Camera Z-Axi s)—Sets the
falloff direction relative to the camera (or
screen). Changing object orientation doesn’t
affect the falloff map. (Default.)
•
Came ra X/Y Axis—Similar to Camera Z-Axis.
For example, using Camera X-Axis with the
Toward/Away fal loff ty pe ru ns the gradient
from left (Toward) to right (Away).