9

938 Glossary
Configuration dialog. You can type a value in the
FOV field of the dialog to precisely set FOV for the
active Perspective view.
Use Field of View (FOV) to change the amount of
thescenevisibleandtheamountofperspective
flare applied to a Perspective or Camera view.
The Field of View button appears in the viewport
navigation control panel when a Perspective or
Camera view is active.
Fi eld s
Two fields combine to make a single frame.
Your animations might u ltimately b e viewed
on television monitors. Standard video signals
display animation by breaking it dow n within time
segments (f r ames). The image for each f rame is
split into horizontal lines (scan lines). A special
method for con v eying frame information on a
video signal has been developed. This method is
called field interlacing. Television monitors display
a video signal by separately scanning two portions
of each frame called fields. One field contains the
odd scan lines of a frame, the other field contains
theevenscanlines.Televisionmonitorsscanand
display the fields of each frame separately. The
fields are alternately cycled through e very other
horizontal line on the screen so that they "layer"
together to form a single interlaced image.
Render to Fields
On the Render Scene dialog, in t he Common
Parameters rollout (page 3–27) >Optionsgroup,
the Render To Fields check box sets whether the
renderer renders full frames at the specified frame
rate, or renders fields at twice that rate. When
Render To Fields is on, the renderer renders an
extra sub-frame image between every two frames,
and composite s each f r a me and the following
sub-frame into a single image with two fields. The
result is a 60 fields-per-second animation suitable
for play on an NT SC (page 3–980) television
monitor.
Fi eld Ord e r
When you render to fields, you also specify a
field order to identify which field comes first.
The Field Order configuration setting is found in
Preferences, on the Rendering page. A frame’s
scan lines are numbered and each field cont ains
either the odd or even scan lines. The video source
(for example, broadcast transmitter, v ideo tape
recorder, or digital video recorder) determines
which group of scan lines is in each field and which
group is delivered to the display first. The fields are
referred to as Field 1 (F1) and Field 2 (F2); either
could contain the o dd numbered (1st, 3rd, 5th,
and so on) scan lines or the even numbered (2nd,
4th, 6th, and so on) scan lines in the frame.
Using the default setting of Odd as your Field
Order preference, the software renders the first
field image (F1) to the odd scan lines. If the field
order preference is set to Even, then the first field
image is rendered to the even scan lines. For an
image to display properly, the field order and the
video device field order must match.
Somevideosystemsrequireoddlinestobe
rendered first, and others require the even lines
to be recorded first. The Field Order parameter
is set to Odd by default. If you observe incorrect