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Controlling Rotation
Below the Transform controller is the Rotation controller. Rotation is a data
type that can use most of the standard controllers such as TCB, Linear, and
Noise.
Rotations in 3D are very complex. Even the standard controller types behave
differently when used for rotation. The most common way of calculating
rotations in 3D animation uses four components to define rotation about an
arbitrary axis. This is the quaternion method.
The benefits of using quaternion rotation include:
■ It produces a direct one-to-one relationship between the quaternion values
and how objects interactively rotate in the scene.
■ It produces smoother rotation than other methods.
The drawbacks of using quaternion rotation include:
■ Rotation values in key information can be difficult to understand.
■ Quaternion rotation controllers do not display function curves in Track
View — Curve Editor. For this reason Euler XYZ is now the default rotation
controller assigned to all objects.
You can use the following controllers only as rotation controllers.
Smooth Rotation
Use
Smooth Rotation on page 3253 when you want rotation to have a smooth
and natural look. Smooth rotation uses nonadjustable curved interpolation,
and has the following characteristics:
■ You can move keys in Track View to change timing.
■ You can directly rotate objects in the viewports to change rotation values.
■ You cannot display controller or key properties, or function curves.
Euler XYZ Rotation
Use the
Euler XYZ Rotation controller on page 3151 when you want individual
function curve control for each axis of rotation. Euler XYZ is a compound
controller that combines separate, single-value float controllers to specify an
3118 | Chapter 15 Animation