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48 Chapter 17: Rendering
Decreasing this value results in a g rainier effect,
but renders more quickly. Default=250.
Tip: To get a “ f i r st draft” pre v iew of t h e e f fe c t of
light tracing, reduce the v alue of Rays/Sample and
the Filter Size.
Changing the num ber of rays per sample
The higher the value, the less grain
Color Filter—Filters all lig ht falling on objects. Set
to a color other than white to tint the ov erall effect.
Default=white.
Filter S ize—The size, in pixels, of the filter used to
reduce noise in the effect. Default=0.5.
Tip: Filter Size is especial ly useful w hen Adaptive
Undersampling is turned off, and Rays/Sample has
alowvalue.
Changing the Filter Size value
Increasing Filter Size reduces noise in the rendering.
Ex tra A mbient—When set to a color other than
black, adds that color as extra ambient lig ht on
objects. Default=black.
Ray Bias—Ray Bias, like Ray-Trace Bias for shadows
(page 3–1000), adjusts the positioning of the
bounced light effects. Use it to correct rendering
artifacts, such as the banding that can occur when
an object casts shadows on itself. Default=0.03.
Bounces—The number of light-ray bounces that
are traced. Increasing this value increases the
amount of color bleeding. Lower values give faster
results w ith less accuracy, and typically produce
darker images. Higher values allow more light
to flow through the scene, resulting in brighter,
more accurate images at a cost of rendering time.
Default=0.
WhenBouncesequals0,theLightTracer
disregards volumetric lighting.
Tip: If your scene has transparent objects such as
glass, increase Bounces to be g reater t han zero. Be
aware that this increases rendering time.