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100 Chapter 17: Rendering
(fully opaque, or 255 in ei g ht-bit encoding).
Default=0.05.
•
Co lor sw atch—Click to display a Color Selector
(page 1–161) to let you specify the R, G, and B
threshold values interactively.
Options group
Lock S a mpl es —When on, the mental ray renderer
uses the same sampling pattern for ever y frame
of an animation. When off, the mental ray
renderer introduces a quasi-random (Monte
Carlo)variationinthesamplepatternfromframe
to frame. Default=on.
Varying the sample pattern reduces rendering
artifacts in animations.
Jitter—Introduces a variation into sample
locations; see Sampling (page 3–1005).Turningon
Jitter can help reduce aliasing. Default=off.
Bucket Width—Determinesthesizeofeachbucket
in pixels. Range=4 to 512 pixels. Default=48
pixels.
To render the scene, the mental ray renderer
subdivides the image into rectangular sections, or
“buckets.” Using a smaller bucket size causes more
image updates to be generated during rendering.
Updating the image consumes a certain amount
ofCPUcycles.Forsceneswithlittlecomplexity,
smaller buckets can increase the rendering time,
whilelargerbucketscanmakethingsrenderfaster.
For more complex scenes, the reverse is true.
Bucket Order—Lets you spe cify the method by
which mental ray chooses t he next bucket. If you
are using placeholders or distributed rendering,
use the default Hilber t order. Otherwise, you can
choose a method based on how you prefer to see
the image appear as it renders in the rendered
frame window.
•
Hilbert (best)—(The default.) The next bucket
chosen is the one that will trigger the fewest
data transfers.
Tip: Always use Hilbert order when you use
placeholders (see the Translator Options rollout
(page 3–119))ordistributedrendering(see
the Di stributed Bucket Rendering rollout (page
3–124)).
•
Spiral—The buckets begin at the center of the
image, and spiral outward.
•
Left to right—Buckets are rendered in columns,
from bottom to top, left to right.
•
Right to left—Buckets are rendered in columns,
from bottom to top, right to left.
•
Top-down—Buckets are rendered in rows, from
right to left, top to bottom.
•
Bottom-up—Buckets are rendered in rows, from
right to left, b ottom to top.
Fr ame Bu ff e r Type —Lets you choose the bit depth
of the output frame buffer:
•
Integer (16 bits per channel)—Outputs 16 bits
per channel of color information. This is the
defaultoutputformat.
•
Floating-Point (3 2 bit s per channel)—Outputs
32 bits per channel of color information. This
method supports high-dy namic-range imagery
(HDRI).