After Effects cs4 note

Photoshop Files

Although the PSD format does not offer any type of compression,
it offers a few unique advantages when used with
After Effects. Specifi cally, PSD fi les
. Can be imported directly as identical After Effects
compositions; all of the data is preserved and most of
it, including blending modes and even layer styles and
text, remains editable in After Effects. In the Import
File dialog, choose Composition or Composition –
Cropped Layers using the Import Kind pop-up menu

. Can be created from After Effects (File > New > Adobe
Photoshop File or even Layer > New > Adobe Photoshop
File).
. Can include moving footage. More about why you
might want to work with video in Photoshop (for its
paint tools) is included in Chapter 7.
. Can include Live 3D layers: 3D models with lighting,
material, and surface characteristics created in Photoshop
that can be manipulated in After Effects. More
about this new feature is found in Chapter 9.
Once your source footage is imported and organized
(Chapter 4), the next step is to place it in a composition.


Composition Settings

My advice is to begin with your plate: the main footage,
whether a background shot or a foreground yet to be
keyed. To ensure that composition settings are exactly as
they should be with the least effort, try one of the following:
. Use a prebuilt project template that includes compositions
whose settings match the intended output; you
can even create and save your own.
. Create a new composition by dragging the plate footage
(often the background plate) to the Create a New
Composition icon . This automatically matches pixel
dimensions, Pixel Aspect Ratio, Frame Rate, and Duration,
all of which are crucial.
Composition Settings also contains an Advanced tab. This
pertains to temporal and spatial settings (Chapter 4) and
motion blur and 3D (Chapter 9).

Previews and View Panels

How exactly does a professional work with footage in After
Effects? I’ve noticed some good habits that experienced
pros tend to share.

Resolution and Quality

First, keep in mind that you should almost never work at
Full resolution, but you should almost always leave layers
at Best quality. There are several effective ways to speed
up previews and interactivity without ever setting a layer to
Draft quality, which creates inaccurate previews by rounding
off crucial values.
In rough order of preference, you can
. Lower viewer Resolution to Half, or in extreme cases,
Quarter (see Note)
. Set a Region of Interest (ROI) to isolate only the area
that needs to be previewed
. Use Shift+RAM Preview to skip frames (default setting
of 1 skips every second frame—details in “Caching and
Previewing,” later in this chapter)

Half resolution allows four times as much data to fi ll a
RAM preview, and Shift+RAM Preview can reduce overhead
further by skipping every nth frame (according to the
Skip setting in the Preview panel). The default setting of 1
plays every other frame (Figure 1.19).
To quickly change the display resolution in the Composition
panel, use the keyboard shortcuts

TABLE 1.2 Display Resolution/Size Shortcuts
RESOLUTION/SIZE KEYBOARD SHORTCUT
Full                Ctrl+J/Cmd+J
Half               Ctrl+Shift+J/Cmd+Shift+J
Quarter         Ctrl+Shift+Alt+J/Cmd+Shift+Option+J
Fit in viewer  Shift+/
Fit up to 100%    Alt+/ / Option+/


Hold down the Spacebar or activate the Hand tool
(H, Spacebar, or Middle Mouse Button) to move your
view of a clip around. To zoom in and out, you can use
. Ctrl+=/Cmd+= and Ctrl+-/Cmd+-
. Zoom tool (Z); press Alt/Option to zoom out
. Comma and period keys
. A mouse with a scroll wheel

Ever notice yourself focusing only on a particular section
of a huge image? Use the Region of Interest (ROI) tool
(Figure 1.20), to defi ne a rectangular preview region. Only
the layer data needed to render that area is calculated and
buffered, lengthening RAM previews.
Responsiveness
Has your After Effects UI slowed to crawl as you work on a
big shot? Here’s a quick triage you can try:
. Deactivate Live Update (Figure 1.21a). On by default,
this toggle enables real-time update in the viewers as
you adjust controls. Deactivate it and updates occur
only when you release the mouse.
. Hold Option/Alt as you make adjustments. With Live
Update on, this prevents views from updating. Deactivate
Live Update and the behavior is inverted; the
modifi er keys instead enable real-time updates.
. Activate Caps Lock. If you don’t mind working “blind”
for periods of time, the Caps Lock key prevents updates
to any viewer

. Enable OpenGL. Preferences > Previews includes the
Enable OpenGL option, off by default (and unavailable
with older graphics cards). Enable it, and OpenGLInteractive
mode in a View panel is accelerated in
certain cases, for example when positioning layers in
3D space. There are two OpenGL options, Interactive
and Always On; the former will help you with fast scene
setup, especially in a complicated 3D scene, and the
latter will give you the look of OpenGL at all times as
you work.
In general, the more responsive you can make your user
interface, the better will be the result because you can
make more decisions in a shorter period of time. Just leave
time to double-check the result if you are in the habit of
disabling viewers.


Multiprocessing

Multiprocessing, which allows After Effects to use all of the
processor cores on your system, is disabled by default; this
does not mean that After Effects doesn’t use all of your
procs, just that by default it doesn’t work on more than
one frame at a time, and thus it doesn’t maximize usage of
your system.
The Preferences > Memory & Multiprocessing dialog
contains dynamically updated information related to your
particular system; it is designed to help you make maximum
use of processing power without maxing out the system
for other applications. The decision of how to balance
it is yours. By default, After Effects leaves a given amount
of RAM for other applications, and you can control this
amount in this dialog.
Most users miss the main feature here, the Render Multiple
Frame Simultaneously checkbox, which is disabled by
default. Check this box and After Effects no longer waits
for one frame to render before starting the next; instead
it looks for available memory and CPU to render as many
frames as your system can handle simultaneously.
How much multiprocessing can your system handle?
Once you enable multiprocessing, you can tune how it is
handled:
. Raise the minimum allocation per CPU to help background
processes: 1.0 GB for HD footage below 32 bpc,
2.0 GB for larger than HD and 32 bpc projects (Chapter
11 tells you more about those).
. Weight memory more toward RAM Previews (a foreground
process, so you wait for it) or faster background
renders (while you continue to work).
. Spare whole CPUs for other applications.
The controls and descriptive text in this dialog, along with
the features they describe have been enhanced for CS4