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254 Chapter 18: Effects and Environments
might n eed to use the Perimeter option at times
when the alpha channel is unavailable.
Bright—Filters the source objects based on their
brightness values. The effect is only applied to
objects with a brightness above the spinner setting
This option can be inverted by clicking the I
button next to the spinner
Hue—Filtersthesourceobjectsbytheirhue.Select
the hue by clicking the color swatch next to the
spinner. You can choose hue values from 0 to 255.
ThespinnerbesidetheHuecolorswatchletsyou
enter a variance level so that the glow can find
several different hues in the same range as the
chosen color
Additional Effects group
AdditionalEffectsallowsyoutoapplymapssuch
as Noise to your L ens Effect. You can display the
Material/Map browser by clicking the long button
next to the Apply check box.
Apply—Applies the selected map when act ivated.
Radial Density—Determines where and how much
you would like the additional effects applied.
Click ing the Radial Density button displays the
Radial Density dialog (page 3–256).Usingthe
Radial Density dialog you can create points on
alineandmovethosepointsalongagraphto
determinewheretheadditionaleffectshouldbe
placed around the light. You can also use a map
to determine where the additional effect should
be placed.
Lens Effects Dialogs
Ci rcular Fal lo ff G raph (L e n s
Effects)
Rendering menu > Effects > Environment and Effects
dialog > Effects panel > Add > Add Effect dialog > Lens
Effects > Choose any effect, and click the (>) arrow
button. > Parameters tab of the rollout for that e ffect >
Falloff Curve (under the Circular or S e ction Color group)
The Circular Falloff graph allows you to add weight
to a particular color applied to your Lens Effect.
By weighting the colors that you apply you can
choose to display more of one color than another.
You can also make the transition of colors gradual
from one color to the next or you can create a
sharp e dge to the transition.