Graphics Programs Reference
In-Depth Information
The number of frames played back per second determines the
frame rate
of the anima-
tion. This is denoted as
fps
, or frames per second. The following are the three standard
frame rates for media:
NTSC: 30fps
•
•
PAL: 25fps
•
Film: 24fps
Knowing your output medium is important when beginning an animation project.
Although it isn't crucial, it can affect how you design your framing, create your move-
ments, render your project, and so on. You can change the frame rate and render resolu-
tion at any time in Maya, but it's always better to know as best you can what the final
resolution and fps will be before you begin.
Playing back a 24fps animation at 30fps will yield a slower-moving animation and will
necessitate either repeating some frames to fill in the gaps or ending the animation early.
Conversely, playing a 30fps animation at 24fps will create a faster-moving animation that
will either skip some frames or end later than it should.
3D Coordinate Space and Axes
Three-dimensional space is the virtual area in which you create your models and execute
your animation. It's based on the Cartesian coordinate system, a geometric map of sorts
developed by the brainy René Descartes. Knowing where you are at all times is essential
with a 3D program. You can do so if you understand the toolset you're working with and
the 3D space in which you're working.
Space is defined in three axes—
X
,
Y
, and
Z
—representing width, height, and depth.
The three axes form a numeric grid in which a particular point is defined by
coordinates
set forth as (#,#,#), corresponding to (
X
,
Y
,
Z
), respectively.
At the zero point of these axes is the
origin
. This is at (0,0,0) and is the intersection of
all three axes. The 3D space defined by these three axes is called the
World axis,
in which
the
XYZ
axes are
fixed references
. The axis in
World Space
is always fixed and is represented
in Maya by the XYZ Axis icon in the lower-left corner of the Perspective windows.
Because objects can be oriented in all sorts of directions within the World axis, it's
necessary for each object to have its own width, height, and depth axis independent of
the World axis. This is called the
Local axis
. The Local
axis is the
XYZ-
coordinate space
that is attached to every object in Maya. When that object rotates or moves, its Local
axis rotates and moves with it. This is necessary to make animating an object easier as it
moves and orients about in the World axis.
You'll get a hands-on introduction to Maya's Cartesian coordinate space in the tutorial
in Chapter 2, “Jumping in Headfirst, with Both Feet,” where you'll re-create the solar sys-
tem with the Sun placed at the origin, the planets orbiting the World axis and rotating on
their own Local axes, and moons orbiting the planets and also rotating (see Figure 1.3).
