Ganbar R. - NUKE 101. Professional Compositing and Visual Effects - 2011

GETTING STARTED WITH NUKE 15
3. Hover your mouse pointer over the Viewer and press 1 and 2 several times. See
how the images change from one input to another.
Using this method you can keep monitoring different stages of your composite as you
are working. This is also a good way to compare two images.
playing a clip in the Viewer
Playing a clip is kind of mandatory in a compositing package. Let’s see this piece of
moving image playing in realtime.
This notion of realtime is very subjective in relation to the specific footage you are
using. For film, realtime is 24fps (frames per second). For PAL video, it’s 25fps. For
some other purpose it might be 100fps. Some computers will simply never be able to
play realtime footage of some resolutions and frame rates simply because they are
too slow, no matter what tricks you try to apply to them.
This aside, you can strive to play clips in realtime. First, you can attempt to play footage
in the Viewer itself. You will need to define what realtime is for your footage. This
footage is 25fps. Let’s set the Viewer to 25fps. You do this in the fps field above the
Timebar. When playing, this field will show how fast playback really is instead of how
fast it is supposed to be playing.
FIGURE 1.22 Viewer
fps field.
1. Set the Viewer fps field to 25 (FigUrE 1.22).
Now when you click Play, Nuke will load each frame from the disk, apply any
calculations to it, and present it in the Viewer. It will also cache this image in
its cache file. It will then move on to the next frame. once Nuke caches all the
frames, it will start to load those into the Viewer instead of going back to the originals.
This will allow Nuke better speed in playback. Nuke will now attempt to play
the given frame rate. The fps field will display the actual frame rate that is playing
whether it’s realtime or not.
2. Click the Play Forward button on the Viewer controls. Let it loop a couple of times
to cache, and then see how fast it is actually playing.
3. Click Stop.
Chances are it played pretty well, and close to if not exactely 25 fps. Let’s give it
something more difficult to attempt.
4. Change the value in the fps field to 100.
5. Click Play and again watch how fast Nuke is playing the footage.
Nuke probably isn’t reaching 100fps, but it should be telling you what it is reaching.
How thoughtful.
Note The cache file is a
folder on your hard drive
where Nuke can place
temporary files. You can
set that to be any folder
and any size by changing
the disk cache setting in
Nuke’s preferences.
tip The hot keys for
playing in the Viewer are
easy to use and good
to remember. They are
exactly the same as in
Final Cut Pro: L plays
forward, K pauses, and J
plays backwards. Pressing
L and J one after the
other enables you to easily
rock ’n’ roll your shot.