9

Raytracer Global Parameters Rollout 1529
Maximum Depth—
Sets the maximum recursion
depth. Increasing this value potentially increases
the realism of your rendered scene, at a cost of
rendering time. You can reduce this value to reduce
rendering time. Range=0 to 100. Default=9.
Cutoff Thre shold—Sets a cutoff threshold for
adaptive ray levels. If the contribution of any ray
to the final pixel color drops below the cutoff
threshold, the ray is terminated. Default: 0.05 (5%
of the final pixel color). This can speed up your
rendering time considerably.
Co lor to us e at Max Depth —As a rule, when a ray
reaches the maximum depth, it is rendered the
same color as the background environment. You
can override the color returned at maximum depth
by either selecting a color, or setting an alternative
environment map. This can make the "lost" ray
invi sible in the scene.
Tip: If you are having tr ouble with getting complex
objects to render, especia l ly glass, specify the
maximum recursion color to something obvious,
like magenta, and your background color to
something that contrasts, like c yan. The chances
arethatalotofyourraysaregettinglostineither
maximum recursion or just being shot off into the
world, totally missing anything you think they
should st rike. Try rendering the scene again. If
this is the problem, try reducing the Maximum
Depth value.
•
Specify—Specifies what color the raytracer
returns w hen the ray is considered lost or
trapped. Click the color swatch to change this
color.
•
Background—(The default.) Returns the
background color when the ra y is considered
lost or trapped. For Raytrace material, the
background color is the global environment
background or the environment specified
locallyforthematerial. ForRaytracemap,
the background color is either the g lobal
environment background, or is set locally in
the Raytracer Parameters rollout (page 2–1704).
Global Ray Antialiaser group
Controls in this group let you set global antialiasing
for raytraced maps and materials.
Above: No antialiasing
Below: Antialiasing of reflections
Tip: Tu rning on Sup ersa mple for a R ay t raced
material (in the Raytrace Basic P ar ameters
rollout (page 2–1514)) usually prov ides adequate
antialiasing. Use one of the r aytrace antialiasers
(Fast Adaptive or Multiresolution Adaptive) when
you want to blur reflections or refractions.
On—When on, uses antialiasing. Default=off.
Drop-down list—Chooses which antialiasing
settings to use. There are two alternatives:
•
Fa st Adaptive Antia liaser—(The default.) Uses
theFastAdaptiveantialiaser.
•
Multiresolution Adaptive A ntialiaser—Uses the
Multiresolution Adaptive antialiaser.
...—The button with the ellipsis to the right of
the drop-down list displays another dialog to let
you set antialiasing controls globally. The dialog
displayed depends on which a lternative you chose
in the drop-down list, as follows: